http://www.mdpi.com/journal/insects Latest open access articles published in Insects at http://www.mdpi.com/journal/insects http://www.mdpi.com/2075-4450/4/2/198 The sweetpotato whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) continues to be a serious threat to crops worldwide. The UK holds Protected Zone status against this pest and, as a result, B. tabaci entering on plant material is subjected to a policy of eradication. Both B and Q Bemisia biotypes are now regularly intercepted entering the UK. With increasing reports of neonicotinoid resistance in both these biotypes, it is becoming more problematic to control/eradicate. Therefore, alternative means of control are necessary. Entomopathogenic fungi (Lecanicilllium muscarium and Beauveria bassiana) offer much potential as control agents of B. tabaci within eradication programmes in the UK. Insects 2013-05-16 4 2 Review 10.3390/insects4020198 198 205 2075-4450 2013-05-16 doi: 10.3390/insects4020198 Andrew Cuthbertson http://www.mdpi.com/2075-4450/4/2/185 Tomato leafminer Tuta absoluta (Meyrick) is a major pest of tomato plants in South America. It was first recorded in the UK in 2009 where it has been subjected to eradication policies. The current work outlines T. absoluta development under various UK glasshouse temperatures. The optimum temperature for Tuta development ranged from 19–23 °C. At 19 °C, there was 52% survival of T. absoluta from egg to adult. As temperature increased (23 °C and above) development time of the moth would appear to decrease. Population development ceases between 7 and 10 °C. Only 17% of eggs hatched at 10 °C but no larvae developed through to adult moths. No eggs hatched when maintained at 7 °C. Under laboratory conditions the total lifespan of the moth was longest (72 days) at 13 °C and shortest (35 days) at both 23 and 25 °C. Development from egg to adult took 58 days at 13 °C; 37 days at 19 °C and 23 days at 25 °C. High mortality of larvae occurred under all temperatures tested. First instar larvae were exposed on the leaf surface for approximately 82 minutes before fully tunnelling into the leaf. Adult longevity was longest at 10 °C with moths living for 40 days and shortest at 19 °C where they survived for 16 days. Generally more males than females were produced. The potential of Tuta absoluta to establish populations within UK protected horticulture is discussed. Insects 2013-05-15 4 2 Article 10.3390/insects4020185 185 197 2075-4450 2013-05-15 doi: 10.3390/insects4020185 Andrew Cuthbertson James Mathers Lisa Blackburn Anastasia Korycinska Weiqi Luo Robert Jacobson Phil Northing http://www.mdpi.com/2075-4450/4/2/177 Educate to Eradicate is a K-12 curriculum project using termite biology and control as the basis for science education that has been implemented in over 350 Hawaii public school classrooms. To encourage sustained implementation of the project, we aimed to identify factors that influence the adoption and continuation of pest management curricula in public school classrooms. Regression analysis of teacher survey data were used to create predictive models of teacher continuation. Teachers motivated by “exciting students about science”, who perceived increases in “student understanding and comprehension of major termite knowledge concepts” and/or students as “more interested in termites after participating in this project” were more likely to continue curriculum. Teachers who had worked at their current school over 21 years at the time of curriculum adoption, and/or who identified having subject specialties not listed on the survey were less likely to continue curriculum. Additionally, teachers servicing lower socioeconomic level students were less likely to continue the curricula. Insects 2013-04-15 4 2 Article 10.3390/insects4020177 177 184 2075-4450 2013-04-15 doi: 10.3390/insects4020177 Makena Mason Maria Aihara-Sasaki J. Grace http://www.mdpi.com/2075-4450/4/1/168 Demand for organic cherries offers producers a premium price to improve their commercial viability. Organic standards require that producers find alternatives to pesticides. Soil treatments to control the European cherry fruit fly Rhagoletis cerasi (L.) (Diptera: Tephrididae) appear to be an attractive option. However, soil treatments can only be effective if the migration of flies is low, because mature flies may migrate from near-by trees for oviposition. To examine the general potential of soil treatments and to understand the dispersal and flight behaviour of R. cerasi within orchards, experiments using netting to cover the soil were conducted in two orchards with different pest pressure during two years. The netting reduced flight activity by 77% and fruit infestation by 91%. The data showed that the flies have a dispersal of less than 5 m within orchards, which is very low. The low thresholds for tolerance for infested fruit in the fresh market creates a strong economic incentive for control, therefore, soil covering is a promising strategy for controlling R. cerasi in commercial orchards. Insects 2013-03-12 4 1 Article 10.3390/insects4010168 168 176 2075-4450 2013-03-12 doi: 10.3390/insects4010168 Claudia Daniel Brian Baker http://www.mdpi.com/2075-4450/4/1/153 Amidst ongoing declines in honey bee health, the contributory role of the newer systemic insecticides continues to be intensely debated. Scores of toxicological field experiments, which bee scientists and regulators in the United States have looked to for definitive causal evidence, indicate a lack of support. This paper analyzes the methodological norms that shape the design and interpretation of field toxicological studies. I argue that contemporary field studies of honey bees and pesticides are underpinned by a “control-oriented” approach, which precludes a serious investigation of the indirect and multifactorial ways in which pesticides could drive declines in honey bee health. I trace the historical rise to prominence of this approach in honey bee toxicology to the development of entomology as a science of insecticide development in the United States. Drawing on “complexity-oriented” knowledge practices in ecology, epidemiology, beekeeping and sociology, I suggest an alternative socio-ecological systems approach, which would entail in situ studies that are less concerned with isolating individual factors and more attentive to the interactive and place-based mix of factors affecting honey bee health. Insects 2013-03-05 4 1 Essay 10.3390/insects4010153 153 167 2075-4450 2013-03-05 doi: 10.3390/insects4010153 Sainath Suryanarayanan http://www.mdpi.com/2075-4450/4/1/117 Wireworms (Coleoptera: Elateridae) are important soil dwelling pests worldwide causing yield losses in many crops. The progressive restrictions in the matter of efficient synthetic chemicals for health and environmental care brought out the need for alternative management techniques. This paper summarizes the main potential tools that have been studied up to now and that could be applied together in integrated pest management systems and suggests guidelines for future research. Insects 2013-01-25 4 1 Review 10.3390/insects4010117 117 152 2075-4450 2013-01-25 doi: 10.3390/insects4010117 Fanny Barsics Eric Haubruge François Verheggen http://www.mdpi.com/2075-4450/4/1/104 Mating disruption techniques are used in pest control for many species of insects, yet little is known regarding the environmental persistence of these pheromones following their application and if persistence is affected by climatic conditions. We first studied the persistent effect of ground applications of Luretape® GM in Lymantria dispar (L) mating disruption in VA, USA in 2006. The removal of Luretape® GM indicated that the strong persistent effect of disparlure in the environment reported by previous studies is produced by residual pheromone in the dispensers as opposed to environmental contamination. In 2010 and 2011, we evaluated the efficacy of two formulations, Disrupt® II and SPLAT GMTM, in VA and WI, USA, which presented different climatic conditions. In plots treated in WI and VA, male moth catches in pheromone-baited traps were reduced in the year of treatment and one year after the pheromone applications relative to untreated controls. However, similar first- and second-year effects of pheromone treatments in VA and WI suggest that the release rate over one and two years was the same across markedly different climates. Future applications that use liquid or biodegradable formulations of synthetic pheromones could reduce the amount of persistence in the environment. Insects 2013-01-14 4 1 Article 10.3390/insects4010104 104 116 2075-4450 2013-01-14 doi: 10.3390/insects4010104 Ksenia Onufrieva Kevin Thorpe Andrea Hickman Donna Leonard E. Roberts Patrick Tobin http://www.mdpi.com/2075-4450/4/1/90 RNA interference has been frequently applied to modulate gene function in organisms where the production and maintenance of mutants is challenging, as in our model of study, the honey bee, Apis mellifera. A green fluorescent protein (GFP)-derived double-stranded RNA (dsRNA-GFP) is currently commonly used as control in honey bee RNAi experiments, since its gene does not exist in the A. mellifera genome. Although dsRNA-GFP is not expected to trigger RNAi responses in treated bees, undesirable effects on gene expression, pigmentation or developmental timing are often observed. Here, we performed three independent experiments using microarrays to examine the effect of dsRNA-GFP treatment (introduced by feeding) on global gene expression patterns in developing worker bees. Our data revealed that the expression of nearly 1,400 genes was altered in response to dsRNA-GFP, representing around 10% of known honey bee genes. Expression changes appear to be the result of both direct off-target effects and indirect downstream secondary effects; indeed, there were several instances of sequence similarity between putative siRNAs generated from the dsRNA-GFP construct and genes whose expression levels were altered. In general, the affected genes are involved in important developmental and metabolic processes associated with RNA processing and transport, hormone metabolism, immunity, response to external stimulus and to stress. These results suggest that multiple dsRNA controls should be employed in RNAi studies in honey bees. Furthermore, any RNAi studies involving these genes affected by dsRNA-GFP in our studies should use a different dsRNA control. Insects 2013-01-04 4 1 Article 10.3390/insects4010090 90 103 2075-4450 2013-01-04 doi: 10.3390/insects4010090 Francis Nunes Aline Aleixo Angel Barchuk Ana Bomtorin Christina Grozinger Zilá Simões http://www.mdpi.com/2075-4450/4/1/71 The effects of sublethal pesticide exposure on queen emergence and virus titers were examined. Queen rearing colonies were fed pollen with chlorpyrifos (CPF) alone (pollen-1) and with CPF and the fungicide Pristine® (pollen-2). Fewer queens emerged when larvae from open foraging (i.e., outside) colonies were reared in colonies fed pollen-1 or 2 compared with when those larvae were reared in outside colonies. Larvae grafted from and reared in colonies fed pollen-2 had lower rates of queen emergence than pollen-1 or outside colonies. Deformed wing virus (DWV) and black queen cell virus were found in nurse bees from colonies fed pollen-1 or 2 and in outside colonies. The viruses also were detected in queen larvae. However, we did not detect virus in emerged queens grafted from and reared in outside colonies. In contrast, DWV was found in all emerged queens grafted from colonies fed pollen-1 or 2 either reared in outside hives or those fed pollen-1 or 2. The results suggest that sublethal exposure of CPF alone but especially when Pristine® is added reduces queen emergence possibly due to compromised immunity in developing queens. Insects 2013-01-04 4 1 Article 10.3390/insects4010071 71 89 2075-4450 2013-01-04 doi: 10.3390/insects4010071 Gloria DeGrandi-Hoffman Yanping Chen Roger Simonds http://www.mdpi.com/2075-4450/4/1/55 The history of classical biological control of fruit flies in Brazil includes two reported attempts in the past 70 years. The first occurred in 1937 when an African species of parasitoid larvae (Tetrastichus giffardianus) was introduced to control the Mediterranean fruit fly, Ceratitis capitata and other tephritids. The second occurred in September 1994 when the exotic parasitoid Diachasmimorpha longicaudata, originally from Gainesville, Florida, was introduced by a Brazilian agricultural corporation (EMBRAPA) to evaluate the parasitoid’s potential for the biological control of Anastrepha spp. and Ceratitis capitata. Although there are numerous native Brazilian fruit fly parasitoids, mass rearing of these native species is difficult. Thus, D. longicaudata was chosen due to its specificity for the family Tephritidae and its ease of laboratory rearing. In this paper we review the literature on Brazilian fruit fly biological control and suggest that those tactics can be used on a large scale, together creating a biological barrier to the introduction of new fruit fly populations, reducing the source of outbreaks and the risk of species spread, while decreasing the use of insecticides on fruit destined for domestic and foreign markets. Insects 2012-12-21 4 1 Review 10.3390/insects4010055 55 70 2075-4450 2012-12-21 doi: 10.3390/insects4010055 Flávio Garcia Marcelo Ricalde http://www.mdpi.com/2075-4450/4/1/31 The Colorado potato beetle (CPB) has been a major insect pest to potato farming for over 150 years and various control methods have been established to reduce its impact on potato fields. Crop rotation and pesticide use are currently the most widely used approaches, although alternative methods are being developed. Here we review the role of various volatile and nonvolatile chemicals involved in behavior changes of CPB that may have potential for their control. First, we describe all volatile and nonvolatile chemicals involved in host plant localization and acceptance by CPB beetles, including glycoalcaloids and host plant volatiles used as kairomones. In the second section, we present the chemical signals used by CPB in intraspecific communication, including sex and aggregation pheromones. Some of these chemicals are used by natural enemies of CPBs to locate their prey and are presented in the third section. The last section of this review is devoted a discussion of the potential of some natural chemicals in biological control of CPB and to approaches that already reached efficient field applications. Insects 2012-12-20 4 1 Review 10.3390/insects4010031 31 54 2075-4450 2012-12-20 doi: 10.3390/insects4010031 Ludovic Sablon Joseph Dickens Éric Haubruge François Verheggen http://www.mdpi.com/2075-4450/4/1/9 Honey bees move through a series of in-hive tasks (e.g., “nursing”) to outside tasks (e.g., “foraging”) that are coincident with physiological changes and higher levels of metabolic activity. Social context can cause worker bees to speed up or slow down this process, and foragers may revert back to their earlier in-hive tasks accompanied by reversion to earlier physiological states. To investigate the effects of flight, behavioral state and age on gene expression, we used whole-genome microarrays and real-time PCR. Brain tissue and flight muscle exhibited different patterns of expression during behavioral transitions, with expression patterns in the brain reflecting both age and behavior, and expression patterns in flight muscle being primarily determined by age. Our data suggest that the transition from behaviors requiring little to no flight (nursing) to those requiring prolonged flight bouts (foraging), rather than the amount of previous flight per se, has a major effect on gene expression. Following behavioral reversion there was a partial reversion in gene expression but some aspects of forager expression patterns, such as those for genes involved in immune function, remained. Combined with our real-time PCR data, these data suggest an epigenetic control and energy balance role in honey bee functional senescence. Insects 2012-12-20 4 1 Article 10.3390/insects4010009 9 30 2075-4450 2012-12-20 doi: 10.3390/insects4010009 Joseph Margotta Georgina Mancinelli Azucena Benito Andrew Ammons Stephen Roberts Michelle Elekonich http://www.mdpi.com/2075-4450/4/1/1 This laboratory study examined viability and infectivity of the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora Poinar in solutions containing four different turfgrass soil surfactants: Revolution (Aquatrols Corp., Paulsboro, NJ), Aqueduct (Aquatrols Corp., Paulsboro, NJ), Cascade Plus (Precision Laboratories Inc., Waukegan, IL) and OARS (Aqua-Aid Inc., Rocky Mount, NC). Infective juvenile H. bacteriophora were added to solutions containing each of the four surfactants, and nematode viability and infectivity were monitored over time. In one of two trials, nematode survival in solutions containing the surfactants Aqueduct and Cascade Plus was consistently higher compared to the water control and solutions containing Revolution or OARS. Surfactants had no significant influence on nematode infectivity in either trial. Findings indicate that most of the common turfgrass soil surfactants examined should be compatible with EPNs and that some may potentially enhance nematode survival. Results also imply that tank-mixing of EPNs with most turfgrass soil surfactants should not pose a significant risk to the nematodes. The influence of soil surfactants on EPN performance remains to be examined in the field. Insects 2012-12-20 4 1 Article 10.3390/insects4010001 1 8 2075-4450 2012-12-20 doi: 10.3390/insects4010001 Terri Hoctor Timothy Gibb Cale Bigelow Douglas Richmond http://www.mdpi.com/2075-4450/3/4/1271 The biological concept of stress originated in mammals, where a “General Adaptation Syndrome” describes a set of common integrated physiological responses to diverse noxious agents. Physiological mechanisms of stress in mammals have been extensively investigated through diverse behavioral and physiological studies. One of the main elements of the stress response pathway is the endocrine hypothalamo-pituitary-adrenal (HPA) axis, which underlies the “fight-or-flight” response via a hormonal cascade of catecholamines and corticoid hormones. Physiological responses to stress have been studied more recently in insects: they involve biogenic amines (octopamine, dopamine), neuropeptides (allatostatin, corazonin) and metabolic hormones (adipokinetic hormone, diuretic hormone). Here, we review elements of the physiological stress response that are or may be specific to honey bees, given the economical and ecological impact of this species. This review proposes a hypothetical integrated honey bee stress pathway somewhat analogous to the mammalian HPA, involving the brain and, particularly, the neurohemal organ corpora cardiaca and peripheral targets, including energy storage organs (fat body and crop). We discuss how this system can organize rapid coordinated changes in metabolic activity and arousal, in response to adverse environmental stimuli. We highlight physiological elements of the general stress responses that are specific to honey bees, and the areas in which we lack information to stimulate more research into how this fascinating and vital insect responds to stress. Insects 2012-12-11 3 4 Review 10.3390/insects3041271 1271 1298 2075-4450 2012-12-11 doi: 10.3390/insects3041271 Naïla Even Jean-Marc Devaud Andrew Barron http://www.mdpi.com/2075-4450/3/4/1257 Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006–2011) from full leaf expansion in May to leaf fall in October in “Desirable” variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids. Insects 2012-12-05 3 4 Article 10.3390/insects3041257 1257 1270 2075-4450 2012-12-05 doi: 10.3390/insects3041257 James Dutcher Haider Karar Ghulam Abbas http://www.mdpi.com/2075-4450/3/4/1236 Antagonistic relationships between parasitoids and their insect hosts involve multiple traits and are shaped by their ecological and evolutionary context. The parasitoid wasp Cotesia melitaearum and its host butterfly Melitaea cinxia occur in several locations around the Baltic sea, with differences in landscape structure, population sizes and the histories of the populations. We compared the virulence of the parasitoid and the susceptibility of the host from five populations in a reciprocal transplant-style experiment using the progeny of five independent host and parasitoid individuals from each population. The host populations showed significant differences in the rate of encapsulation and parasitoid development rate. The parasitoid populations differed in brood size, development rate, pupal size and adult longevity. Some trait differences depended on specific host-parasitoid combinations, but neither species performed systematically better or worse in experiments involving local versus non-local populations of the other species. Furthermore, individuals from host populations with the most recent common ancestry did not perform alike, and there was no negative effect due to a history of inbreeding in the parasitoid. The complex pattern of variation in the traits related to the vulnerability of the host and the ability of the parasitoid to exploit the host may reflect multiple functions of the traits that would hinder simple local adaptation. Insects 2012-12-05 3 4 Article 10.3390/insects3041236 1236 1256 2075-4450 2012-12-05 doi: 10.3390/insects3041236 Saskya van Nouhuys Suvi Niemikapee Ilkka Hanski http://www.mdpi.com/2075-4450/3/4/1220 Augmentative releases of parasitoids may be a useful tool for the area-wide management of tephritid pests. The latter are parasitized by many wasp species, though only a few of them are relevant for augmentative biocontrol purposes. To date, nearly all the actual or potential biocontrol agents for such programs are egg or larval Opiinae parasitoids (Hymenoptera: Braconidae). Here, we review the literature published on their habitat and host location behavior, as well as the factors that modulate this behavior, which is assumed to be sequential; parasitoids forage first for the host habitat and then for the host itself. Parasitoids rely on chemical, visual, and mechanical stimuli, often strongly related to their ecology. Behavioral modulation factors include biotic and abiotic factors including learning, climatic conditions and physiological state of the insect. Finally, conclusions and perspectives for future research are briefly highlighted. A detailed knowledge of this behavior may be very useful for selecting the release sites for both inundative/augmentative releases of mass-reared parasitoids and inoculative releases for classical biocontrol. Insects 2012-11-22 3 4 Review 10.3390/insects3041220 1220 1235 2075-4450 2012-11-22 doi: 10.3390/insects3041220 Serge Quilici Pascal Rousse http://www.mdpi.com/2075-4450/3/4/1200 As key factors in intercellular adhesion processes, cadherins play important roles in a plethora of developmental processes, including gametogenesis. In a previous study on cadherin localization in the gonads of honey bees, performed with heterologous pan-cadherin antibodies, we detected these proteins as (i) associated with cell membranes, (ii) as homogeneously distributed throughout the cytoplasm, and (iii) as nuclear foci in both somatic and germline cells, raising the possibility of alternative functions. To further investigate such unusual intracellular cadherin localization we produced specific antibodies against the N- and C-terminal domains of honey bee N- and E-cadherin. A 160 kDa protein was recognized by the E-cadherin antibodies as well as one of approximately 300 kDa from those raised against N-cadherin. In gonad preparations, both proteins were detected as dispersed throughout the cytoplasm and as nuclear foci in both germline and somatic cells of queen and worker ovarioles, as well as in the testioles of drones. This leads us to infer that cadherins may indeed be involved in certain signaling pathways and/or transcriptional regulation during gametogenesis. In late oogenesis stages, immunolabeling for both proteins was observed at the cell cortex, in conformity with a role in cell adhesion. In testioles, E-cadherin was seen in co-localization with fusomes, indicating a possible role in cyst organization. Taken together, the distribution of N- and E-cadherins in honey bee gonads is suggestive of alternative roles for cadherins in gametogenesis of both sexes. Insects 2012-11-22 3 4 Article 10.3390/insects3041200 1200 1219 2075-4450 2012-11-22 doi: 10.3390/insects3041200 Mônica Florecki Klaus Hartfelder http://www.mdpi.com/2075-4450/3/4/1190 The Formosan subterranean termite (Coptotermes formosanus) is an important worldwide pest, each year causing millions of dollars in structural damage and control costs. Termite colonies are composed of several phenotypically distinct castes. Termites utilize these multiple castes to efficiently perform unique roles within the colony. During the molting/caste differentiation process, multiple genes are believed to be involved in the massive reorganization of the body plan. The objective of this research was to analyze the muscle gene, myosin, to further understand the role it plays in C. formosanus development. We find that comparing worker vs. solider caste myosin gene expression is up-regulated in the soldier and a myosin antibody-reactive protein suggests changes in splicing. Comparison of body regions of mature soldier and worker castes indicates a greater level of myosin transcript in the heads. The differential expression of this important muscle-related gene is anticipated considering the large amount of body plan reorganization and muscle found in the soldier caste. These results have a direct impact on our understanding of the downstream genes in the caste differentiation process and may lead to new targets for termite control. Insects 2012-11-16 3 4 Article 10.3390/insects3041190 1190 1199 2075-4450 2012-11-16 doi: 10.3390/insects3041190 Matthew R. Tarver Christopher B. Florane Christopher P. Mattison Beth A. Holloway Alan Lax http://www.mdpi.com/2075-4450/3/4/1171 The current changes in global climatic regimes present a significant societal challenge, affecting in all likelihood insect physiology, biochemistry, biogeography and population dynamics. With the increasing resistance of many insect pest species to chemical insecticides and an increasing organic food market, pest control strategies are slowly shifting towards more sustainable, ecologically sound and economically viable options. Biologically based pest management strategies present such opportunities through predation or parasitism of pests and plant direct or indirect defense mechanisms that can all be important components of sustainable integrated pest management programs. Inevitably, the efficacy of biological control systems is highly dependent on natural enemy-prey interactions, which will likely be modified by changing climates. Therefore, knowledge of how insect pests and their natural enemies respond to climate variation is of fundamental importance in understanding biological insect pest management under global climate change. Here, we discuss biological control, its challenges under climate change scenarios and how increased global temperatures will require adaptive management strategies to cope with changing status of insects and their natural enemies. Insects 2012-11-09 3 4 Article 10.3390/insects3041171 1171 1189 2075-4450 2012-11-09 doi: 10.3390/insects3041171 Frank Chidawanyika Pride Mudavanhu Casper Nyamukondiwa http://www.mdpi.com/2075-4450/3/4/1156 Habitat modification and fragmentation are considered as some of the factors that drive organism distribution and host use diversification. Indigenous African stem borer pests are thought to have diversified their host ranges to include maize [Zea mays L.] and sorghum [Sorghum bicolor (L.) Moench] in response to their increased availability through extensive cultivation. However, management efforts have been geared towards reducing pest populations in the cultivated fields with few attempts to understand possible evolution of "new" pest species. Recovery and growing persistence of Busseola segeta Bowden on maize (Zea mays L.) in Kakamega called for studies on the role of wild host plants on the invasion of crops by wild borer species. A two-year survey was carried out in a small agricultural landscape along the edge of Kakamega forest (Kenya) to assess host range and population genetic structure of B. segeta. The larvae of B. segeta were found on nine different plant species with the majority occurring on maize and sorghum. Of forty cytochrome b haplotypes identified, twenty-three occurred in both wild and cultivated habitats. The moths appear to fly long distances across the habitats with genetic analyses revealing weak differentiation between hosts in different habitats (FST = 0.016; p = 0.015). However, there was strong evidence of variation in genetic composition between growing seasons in the wild habitat (FST = 0.060; p < 0.001) with emergence or disappearance of haplotypes between habitats. Busseola segeta is an example of a phytophagous insect that utilizes plants with a human induced distribution range, maize, but does not show evidence of host race formation or reduction of gene flow among populations using different hosts. However, B. segeta is capable of becoming an important pest in the area and the current low densities may be attributed to the general low infestation levels and presence of a wide range of alternative hosts in the area. Insects 2012-11-06 3 4 Article 10.3390/insects3041156 1156 1170 2075-4450 2012-11-06 doi: 10.3390/insects3041156 George O. Ong'amo Bruno P. Le Ru Pascal Campagne Antoine Branca Paul-Andre Calatayud Claire Capdevielle-Dulac Jean-Francois Silvain http://www.mdpi.com/2075-4450/3/4/1143 Since 2006, beekeepers have reported increased losses of Apis mellifera colonies, and one factor that has been potentially implicated in these losses is the microsporidian Nosema ceranae. Since N. ceranae is a fairly recently discovered parasite, there is little knowledge of the variation in infection levels among individual workers within a colony. In this study we examined the levels of infection in individual bees from five colonies over three seasons using both spore counting and quantitative real-time PCR. The results show considerable intra-colony variation in infection intensity among individual workers with a higher percentage of low-level infections detected by PCR than by spore counting. Colonies generally had the highest percentage of infected bees in early summer (June) and the lowest levels in the fall (September). Nosema apis was detected in only 16/705 bees (2.3%) and always as a low-level co-infection with N. ceranae. The results also indicate that intra-colony variation in infection levels could influence the accuracy of Nosema diagnosis. Insects 2012-11-01 3 4 Article 10.3390/insects3041143 1143 1155 2075-4450 2012-11-01 doi: 10.3390/insects3041143 Grace Mulholland Brenna Traver Nels Johnson Richard Fell http://www.mdpi.com/2075-4450/3/4/1126 Integrated pest management (IPM), which combines physical, biological, and chemical control measures to complementary effect, is one of the most important approaches to environmentally friendly sustainable agriculture. To expand IPM, we need to develop new pest control measures, reinforce existing measures, and investigate interactions between measures. Continued progress in the development of environmental control technologies and consequent price drops have facilitated their integration into plant production and pest control. Here I describe environmental control technologies for the IPM of spider mites through: (1) the disturbance of photoperiod-dependent diapause by artificial light, which may lead to death in seasonal environments; (2) the use of ultraviolet radiation to kill or repel mites; and (3) the use of water vapor control for the long-term cold storage of commercially available natural enemies. Such environmental control technologies have great potential for the efficient control of spider mites through direct physical effects and indirect effects via natural enemies. Insects 2012-10-26 3 4 Review 10.3390/insects3041126 1126 1142 2075-4450 2012-10-26 doi: 10.3390/insects3041126 Takeshi Suzuki http://www.mdpi.com/2075-4450/3/4/1105 The use of irradiated hosts in mass rearing tephritid parasitoids represents an important technical advance in fruit fly augmentative biological control. Irradiation assures that fly emergence is avoided in non-parasitized hosts, while at the same time it has no appreciable effect on parasitoid quality, i.e., fecundity, longevity and flight capability. Parasitoids of fruit fly eggs, larvae and pupae have all been shown to successfully develop in irradiated hosts, allowing a broad range of species to be shipped and released without post-rearing delays waiting for fly emergence and costly procedures to separate flies and wasps. This facilitates the early, more effective and less damaging shipment of natural enemies within hosts and across quarantined borders. In addition, the survival and dispersal of released parasitoids can be monitored by placing irradiated sentinel-hosts in the field. The optimal radiation dosages for host-sterility and parasitoid-fitness differ among species, and considerable progress has been made in integrating radiation into a variety of rearing procedures. Insects 2012-10-25 3 4 Review 10.3390/insects3041105 1105 1125 2075-4450 2012-10-25 doi: 10.3390/insects3041105 Jorge Cancino Lía Ruíz Mariana Viscarret John Sivinski Jorge Hendrichs http://www.mdpi.com/2075-4450/3/4/1093 Pattern recognition receptors play an important role in insect immune defense. We cloned the β-1,3-glucan recognition protein, lectin-5 and C-type lectin 1 genes of Antheraea pernyi and examined the expression profiles of immune-stimulated pupae. After infection with Bacillus subtilis, Escherichia coli, Antheraea pernyi nuclear polyhedrosis virus (ApNPV) and Saccharomyces cerevisiae, respectively, the pupae showed different gene expression levels in the different tissues examined (midgut, fatbody, epidermis, testis, and hemocytes). ApβGRP and Aplectin-5 was induced by all the microorganisms, and mainly in epidermis and hemocytes, but not in testis; Aplectin-5 was also expressed in fatbody. Ap C-type lectin 1 was, on the contrary, highly expressed in testis and also in fatbody, but not in hemocytes. Unlike ApβGRP and Aplectin-5, Ap C-type lectin 1 was not induced by Gram-positive bacteria. The results suggest that the cloned lectins may have different functions in different tissues of A. pernyi. Insects 2012-10-24 3 4 Article 10.3390/insects3041093 1093 1104 2075-4450 2012-10-24 doi: 10.3390/insects3041093 Fengjuan Li Olle Terenius Yuan Li Suyun Fang Wenli Li http://www.mdpi.com/2075-4450/3/4/1084 The insulin signaling pathway has been hypothesized to play a key role in regulation of worker social insect behavior. We tested whether insulin treatment has direct effects on worker honeybee behavior in two contexts, sucrose response thresholds in winter bees and the progression to foraging by summer nurse bees. Treatment of winter worker bees with bovine insulin, used as a proxy for honeybee insulin, increased the bees’ sucrose response threshold. Treatment of summer nurse bees with bovine insulin significantly decreased the age at which foraging was initiated. This work provides further insight into the role of endocrine controls in behavior of in honeybees and insects in general. Insects 2012-10-24 3 4 Article 10.3390/insects3041084 1084 1092 2075-4450 2012-10-24 doi: 10.3390/insects3041084 Christine Mott Michael Breed http://www.mdpi.com/2075-4450/3/4/1056 This review draws together available information on the biology, methods for study, and culturing of hymenopteran parasitoids of the Queensland fruit fly, Bactrocera tryoni, and assesses prospects for improving biological control of this serious pest. Augmentative release of the native and naturalised Australian parasitoids, especially the braconid Diachasmimorpha tryoni, may result in better management of B. tryoni in some parts of Australia. Mass releases are an especially attractive option for areas of inland eastern Australia around the Fruit Fly Exclusion Zone that produces B. tryoni-free fruits for export. Diachasmimorpha tryoni has been successful in other locations such as Hawaii for the biological control of other fruit fly species. Biological control could contribute to local eradication of isolated outbreaks and more general suppression and/or eradication of the B. tryoni population in endemic areas. Combining biological control with the use of sterile insect technique offers scope for synergy because the former is most effective at high pest densities and the latter most economical when the pest becomes scarce. Recommendations are made on methods for culturing and study of four B. tryoni parasitoids present in Australia along with research priorities for optimising augmentative biological control of B. tryoni. Insects 2012-10-22 3 4 Review 10.3390/insects3041056 1056 1083 2075-4450 2012-10-22 doi: 10.3390/insects3041056 Ashley L. Zamek Jennifer E. Spinner Jessica L. Micallef Geoff M. Gurr Olivia L. Reynolds http://www.mdpi.com/2075-4450/3/4/1039 Hexamerins are storage proteins with primordial functions in insect metamorphosis. They are actively secreted by the larval fat body and stored in the hemolymph. During metamorphosis, they return to the fat body to be processed. For decades, these proteins were thought to exclusively function as an amino acid source for tissue reconstruction during the non-feeding pupal and pharate adult stages and, in some species, for egg production. Recently, new findings have linked the hexamerins to caste polyphenism and gonad development in social insects. To explore the roles of hexamerins during the honey bee metamorphosis, we used specific antibodies in expression analysis by western blot, in situ immunolocalization by confocal laser-scanning microscopy and in vivo injections to lower their endogenous levels. Our expression analysis highlighted the changing expression patterns in the fat body and hemolymph during development, which is consistent with the temporal dynamics of hexamerin secretion, storage and depletion. Confocal microscopy showed hexamerin expression in the cytoplasm of both types of fat body cells, trophocytes and oenocytes. Notably, hexamerin foci were also found in the nuclei of these cells, thus confirming our western blot analysis of fat body nuclear-enriched fractions. We also observed that the decrease in soluble hexamerins in antibody-treated pharate adults led to a precocious adult ecdysis, perhaps in response to the lack (or decrease) in hexamerin-derived amino acids. Taken together, these findings indicate that hexamerins have other functions in addition to their well-established role as amino acid sources for development. Insects 2012-10-22 3 4 Article 10.3390/insects3041039 1039 1055 2075-4450 2012-10-22 doi: 10.3390/insects3041039 Juliana Ramos Martins Márcia Maria Gentile Bitondi http://www.mdpi.com/2075-4450/3/4/1028 Previous dynamic characterizations of the cercal mechanosensory hairs of crickets have generally been limited to the first resonant frequency and associated deflection shape. A more complete description of the mechanical dynamics of these structures could be obtained by an experimental modal analysis. This paper describes a method by which a full experimental modal analysis, giving natural frequency, mode shape, and modal damping ratio, of these sense organs can be performed. Results of this analysis, employing an unmeasured moving-air excitation and non-contact vibration measurement with an output-only identification method are presented. Two distinct types of behaviour were observed, one of which was a good match for the behaviour expected based on the literature, and one of which was quite different. These two behaviours had distinct patterns of modal parameters. The method described in this paper has been shown to be able to estimate the modal parameters, including natural frequency, modal damping ratio, and normalized mode shape, for the first mode of cercal mechanosensory hairs of crickets. The method could practically be extended to higher modes and a wide variety of other sound and vibration sense organs with the selection of appropriate excitation and specimen supports. Insects 2012-10-22 3 4 Article 10.3390/insects3041028 1028 1038 2075-4450 2012-10-22 doi: 10.3390/insects3041028 Joel M. Book Samuel F. Asokanthan http://www.mdpi.com/2075-4450/3/4/1001 In order to describe seasonal flight activity of the cabbage maggot Delia radicum (L.) adults in relation to Julian days (JD), degree-day accumulations (DDA) and precipitation, flight dynamics were followed weekly with the use of yellow sticky traps (YST). Climatic data were collected and DDA were calculated using the lower developmental threshold of 4.3 °C. The efficacy of four insecticides applied either as standard foliar treatment or through dipping the seedlings before transplanting was determined. Seasonal flight activity during the cultivation season of a mid-early variety of white cabbage was correlated with DDA and JD and was characterized by having two peaks. The first peak occurred between 119 ± 7.5 JD and 125.5 ± 8 JD when DDA was 471.35 ± 74.97 °C. The second occurred between 172.8 ± 6.1 JD and 179.3 ± 6.7 JD when DDA was 1,217.28 ± 96.12 °C. The DDA, cumulative capture of flies and JD are suitable for predicting the timing of insecticide application. Spraying with insecticides should be applied when the cumulative capture of flies reaches 100 flies/YST and when DDA reaches 400 °C. If only one parameter reaches the threshold, additional visual surveys should be employed to establish the level of infestation. Insecticides were able to ensure only partial control. In the future, alternative control tactics which employ seed treatments and nonpesticide measures should be investigated in Croatia. Insects 2012-10-22 3 4 Article 10.3390/insects3041001 1001 1027 2075-4450 2012-10-22 doi: 10.3390/insects3041001 Renata Bažok Mirna Ceranić-Sertić Jasminka Igrc Barčić Josip Borošić Antonela Kozina Tomislav Kos Darija Lemić Maja Čačija http://www.mdpi.com/2075-4450/3/4/989 Nucleopolyhedroviruses (NPV: Gammabaculovirus: Baculoviridae) of diprionid sawflies (Diprionidae: Hymenoptera) are highly host specific and only infect the midgut epithelium. While still alive, infected sawfly larvae excrete NPV-laden diarrhea that contaminates food sources. The diarrhea can then be consumed by conspecific larvae, resulting in rapid horizontal transmission of the virus. To better understand the efficacy of Gammabaculovirus-based biological control products, the horizontal spread of such a virus (NeabNPV) within cohorts of balsam fir sawfly (Neodiprion abietis) larvae was studied by introducing NeabNPV-treated larvae into single-cohort groups at densities similar to those observed during the increasing (field study) and peak (laboratory study) phases of an outbreak. In field studies (~200 N. abietis larvae/m2 of balsam fir (Abies balsamea) foliage), NeabNPV-induced mortality increased positively in a density-dependent manner, from 23% (in control groups) to 51% with the addition of one first-instar NeabNPV-treated larva, to 84% with 10 first–instar-treated larvae. Mortality was 60% and 63% when one or 10 NeabNPV-treated third-instar larva(e), respectively, were introduced into groups. Slightly higher levels of NeabNPV-induced mortality occurring when NeabNPV-treated larvae were introduced into first- rather than third-instar cohorts suggests that early instars are more susceptible to the virus. In the laboratory (~1330 N. abietis larvae/ m2 of foliage), NeabNPV-caused mortality increased from 20% in control groups to over 80% with the introduction of one, five or 10 NeabNPV-treated larvae into treatment groups of first-instar larvae. Insects 2012-10-19 3 4 Article 10.3390/insects3040989 989 1000 2075-4450 2012-10-19 doi: 10.3390/insects3040989 Roger Graves Dan T. Quiring Christopher J. Lucarotti http://www.mdpi.com/2075-4450/3/4/956 The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is a highly destructive pest. The low tolerance for damaged fruit requires preventive insecticide treatments for a marketable crop. The phase-out of old insecticides threatens cherry production throughout the European Union (EU). Consequently, new management techniques and tools are needed. With the increasing number of dwarf tree orchards covered against rain to avoid fruit splitting, crop netting has become a viable, cost-effective method of cherry fruit fly control. Recently, a biocontrol method using the entomopathogenic fungus Beauveria bassiana has been developed for organic agriculture. However, for most situations, there is still a lack of efficient and environmentally sound insecticides to control this pest. This review summarizes the literature from over one hundred years of research on R. cerasi with focus on the biology and history of cherry fruit fly control as well as on antagonists and potential biocontrol organisms. We will present the situation of cherry fruit fly regulation in different European countries, give recommendations for cherry fruit fly control, show gaps in knowledge and identify future research opportunities. Insects 2012-10-16 3 4 Review 10.3390/insects3040956 956 988 2075-4450 2012-10-16 doi: 10.3390/insects3040956 Claudia Daniel Jürg Grunder http://www.mdpi.com/2075-4450/3/4/930 The New World Screwworm, Cochliomyia hominivorax (Coquerel), is one of the most damaging parasites of livestock, causing millions of dollars in annual losses to producers. The fly is an obligate parasite of warm-blooded animals, including humans. After a successful 50-year eradication campaign, C. hominivorax has been eradicated from the USA, Mexico and Central America by an area-wide integrated pest management approach. Recently, Caribbean and South American countries have expressed an interest in this approach. Aiming to support forthcoming projects in these countries, this review describes the main technical components of past and ongoing AW-IPM campaigns against C. hominivorax. Insects 2012-10-12 3 4 Review 10.3390/insects3040930 930 955 2075-4450 2012-10-12 doi: 10.3390/insects3040930 Thiago Mastrangelo John Welch http://www.mdpi.com/2075-4450/3/4/912 Field trials and assessments of the balsam fir sawfly (Neodiprion abietis) nucleopolyhedrovirus (NeabNPV: Baculoviridae, Gammabaculovirus) against its natural host were conducted in July and August 2002 near Corner Brook, Newfoundland and Labrador, Canada, in naturally regenerated, precommercially thinned stands dominated by balsam fir (Abies balsamea). Two experimental blocks, each with its own untreated control, were established. The purpose of the Island Pond block was to examine the spread of NeabNPV from a 313-ha aerial treatment block out into adjacent populations of balsam fir sawflies. The purpose of the Old Man’s Pond block (2,093 ha) was to determine whether NeabNPV could disperse into populations of balsam fir sawflies within a 200-m zone between spray swaths. NeabNPV was applied to treatment blocks by a Cessna 188B AgTruck aircraft equipped with MicronAir AU4000 rotary atomizers at an application rate equivalent to 1 × 109 NeabNPV occlusion bodies/ha in 2.5 L of 20% aqueous molasses. At Island Pond, NeabNPV infection increased with time following the spray, especially for individuals close to the treatment block, and infection rate decreased to a measured distance of 400 m from the treatment block. At Old Man’s Pond, NeabNPV infection rose higher (80% vs. 15%) and sawfly densities declined more (84% vs. 60%) in the area between spray swaths than in the control block. Insects 2012-09-28 3 4 Article 10.3390/insects3040912 912 929 2075-4450 2012-09-28 doi: 10.3390/insects3040912 Roger Graves Christopher J. Lucarotti Dan T. Quiring http://www.mdpi.com/2075-4450/3/4/900 Superparasitism, a strategy in which a female lays eggs in/on a previously parasitized host, was attributed in the past to the inability of females to discriminate between parasitized and non-parasitized hosts. However, superparasitism is now accepted as an adaptive strategy under specific conditions. In fruit fly parasitoids, superparasitism has mainly been studied as concerns the new association between Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) and the Mexican fruit fly Anastrepha ludens (Loew) (Diptera: Tephritidae), wherein this phenomenon is a common occurrence in both mass rearing and field conditions. Studies of this species have shown that moderate levels of superparasitism result in a female-biased sex ratio and that both massreared and wild females superparasitize their hosts without detrimental effects on offspring demographic parameters, including longevity and fecundity. These studies suggest that superparasitism in this species is advantageous. In this paper, we review superparasitism in D. longicaudata, discuss these findings in the context of mass rearing and field releases and address the possible implications of superparasitism in programs employing augmentative releases of parasitoids for the control of fruit fly pests. Insects 2012-09-25 3 4 Review 10.3390/insects3040900 900 911 2075-4450 2012-09-25 doi: 10.3390/insects3040900 Pablo Montoya Gabriela Pérez-Lachaud Pablo Liedo http://www.mdpi.com/2075-4450/3/3/889 The successful application of Augmentative Biological Control (ABC) to control pest fruit flies (Diptera: Tephritidae) confronts two fundamental requirements: (1) the establishment of efficient mass rearing procedures for the species to be released, and (2) the development of methodologies for the packing and release of parasitoids that permit a uniform distribution and their optimal field performance under an area-wide approach. Parasitoid distributions have been performed by ground and by air with moderate results; both options face challenges that remain to be addressed. Different devices and strategies have been used for these purposes, including paper bags and the chilled adult technique, both of which are commonly used when releasing sterile flies. However, insect parasitoids have morphological and behavioral characteristics that render the application of such methodologies suboptimal. In this paper, we discuss an alternate strategy for the augmentative release of parasitoids and describe packing conditions that favor the rearing and emergence of adult parasitoids for increased field performance. We conclude that the use of ABC, including the packaging of parasitoids, requires ongoing development to ensure that this technology remains a viable and effective control technique for pest fruit flies. Insects 2012-09-20 3 3 Review 10.3390/insects3030889 889 899 2075-4450 2012-09-20 doi: 10.3390/insects3030889 Pablo Montoya Jorge Cancino Lía Ruiz http://www.mdpi.com/2075-4450/3/3/870 In Argentina there are two tephritid fruit fly species of major economic and quarantine importance: the exotic Ceratitis capitata that originated from Southeast Africa and the native Anastrepha fraterculus. In recent years, the use of fruit fly parasitoids as biocontrol agents has received renewed attention. This increasing interest has recently led to the establishment of a program for the mass rearing of five million Diachasmimorpha longicaudata parasitoids per week in the BioPlanta San Juan facility, San Juan, Argentina. The first augmentative releases of D. longicaudata in Argentina are currently occurring on commercial fig crops in rural areas of San Juan as part of an integrated fruit fly management program on an area-wide basis. In this context, research is ongoing to assess the suitability of indigenous parasitoid species for successful mass rearing on larvae of either C. capitata or A. fraterculus. The purpose of this article is to provide a historical overview of the biological control of the fruit fly in Argentina, report on the strategies currently used in Argentina, present information on native parasitoids as potential biocontrol agents, and discuss the establishment of a long-term fruit fly biological control program, including augmentative and conservation modalities, in Argentina’s various fruit growing regions. Insects 2012-09-14 3 3 Review 10.3390/insects3030870 870 888 2075-4450 2012-09-14 doi: 10.3390/insects3030870 Sergio M. Ovruski Pablo Schliserman http://www.mdpi.com/2075-4450/3/3/857 A honey bee queen mates with a number of drones a few days after she emerges as an adult. Spermatozoa of different drones are stored in her spermatheca and used for the rest of the queen’s life to fertilize eggs. Sperm usage is thought to be random, so that the patriline distribution within a honey bee colony would remain constant over time. In this study we assigned the progeny of a naturally mated honey bee queen to patrilines using microsatellite markers at the queen’s age of two, three and four years. No significant changes in patriline distribution occurred within each of two foraging seasons, with samples taken one and five months apart, respectively. Overall and pair-wise comparisons between the three analyzed years reached significant levels. Over the three-year period we found a trend for patrilines to become more equally represented with time. It is important to note that this study was performed with a single queen, and thus individual and population variation in sperm usage patterns must be assessed. We discuss long-term changes in patriline composition due to mixing processes in the queen’s spermatheca, following incomplete mixing of different drones’ sperm after mating. Insects 2012-09-13 3 3 Article 10.3390/insects3030857 857 869 2075-4450 2012-09-13 doi: 10.3390/insects3030857 Robert Brodschneider Gérard Arnold Norbert Hrassnigg Karl Crailsheim http://www.mdpi.com/2075-4450/3/3/833 In Giant Honey Bees, abdomen flipping happens in a variety of contexts. It can be either synchronous or cascaded, such as in the collective defense traits of shimmering and rearing-up, or it can happen as single-agent behavior. Abdomen flipping is also involved in flickering behavior, which occurs regularly under quiescent colony state displaying singular or collective traits, with stochastic, and (semi-) synchronized properties. It presumably acts via visual, mechanoceptive, and pheromonal pathways and its goals are still unknown. This study questions whether flickering is preliminary to shimmering which is subject of the fs (flickering-shimmering)-transition hypothesis? We tested the respective prediction that trigger sites (ts) at the nest surface (where shimmering waves had been generated) show higher flickering activity than the alternative non-trigger sites (nts). We measured the flickering activity of ts- and nts-surface bees from two experimental nests, before and after the colony had been aroused by a dummy wasp. Arousal increased rate and intensity of the flickering activity of both ts- and nts cohorts (P < 0.05), whereby the flickering intensity of ts-bees were higher than that of nts-bees (P < 0.05). Under arousal, the colonies also increased the number of flickering-active ts- and nts-cohorts (P < 0.05). This provides evidence that cohorts which are specialist at launching shimmering waves are found across the quiescent nest zone. It also proves that arousal may reinforce the responsiveness of quiescent curtain bees for participating in shimmering, practically by recruiting additional trigger site bees for expanding repetition of rate and intensity of shimmering waves. This finding confirms the fs-transition hypothesis and constitutes evidence that flickering is part of a basal colony-intrinsic information system. Furthermore, the findings disprove that the muscle activity associated with flickering would heat up the surface bees. Hence, surface bees are not actively contributing to thermoregulation. Insects 2012-08-30 3 3 Article 10.3390/insects3030833 833 856 2075-4450 2012-08-30 doi: 10.3390/insects3030833 Frank Weihmann Thomas Hoetzl Gerald Kastberger http://www.mdpi.com/2075-4450/3/3/821 This work verifies that amitraz and oxalic acid treatment affect honeybee cuticle proteolytic enzymes (CPE). Three bee groups were monitored: oxalic acid treatment, amitraz treatment, control. Electrophoresis of hydrophilic and hydrophobic CPE was performed. Protease and protease inhibitor activities (in vitro) and antifungal/antibacterial efficiencies (in vivo), were analyzed. Amitraz and oxalic acid treatment reduced hydrophobic, but did not affect hydrophilic, protein concentrations and reduced both hydrophilic and hydrophobic body surface asparagine and serine protease activities in relation to most substrates and independently of pH. The activities of natural cuticle inhibitors of acidic, neutral, and alkaline proteases were suppressed as a result of the treatments, corresponding with reduced antifungal and antibacterial activity. Electrophoretic patterns of low-, medium-, and high-molecular-weight proteases and protease inhibitors were also affected by the treatments. Insects 2012-08-27 3 3 Article 10.3390/insects3030821 821 832 2075-4450 2012-08-27 doi: 10.3390/insects3030821 Aneta Strachecka Jerzy Paleolog Krzysztof Olszewski Grzegorz Borsuk http://www.mdpi.com/2075-4450/3/3/789 Parasites can dramatically reduce the fitness of their hosts, and natural selection should favor defense mechanisms that can protect hosts against disease. Much work has focused on understanding genetic and physiological immunity against parasites, but hosts can also use behaviors to avoid infection, reduce parasite growth or alleviate disease symptoms. It is increasingly recognized that such behaviors are common in insects, providing strong protection against parasites and parasitoids. We review the current evidence for behavioral immunity in insects, present a framework for investigating such behavior, and emphasize that behavioral immunity may act through indirect rather than direct fitness benefits. We also discuss the implications for host-parasite co-evolution, local adaptation, and the evolution of non-behavioral physiological immune systems. Finally, we argue that the study of behavioral immunity in insects has much to offer for investigations in vertebrates, in which this topic has traditionally been studied. Insects 2012-08-15 3 3 Review 10.3390/insects3030789 789 820 2075-4450 2012-08-15 doi: 10.3390/insects3030789 Jacobus C. de Roode Thierry Lefèvre http://www.mdpi.com/2075-4450/3/3/763 Parasitoid detection and identification is a necessary step in the development and implementation of fruit fly biological control strategies employing parasitoid augmentive release. In recent years, DNA-based methods have been used to identify natural enemies of pest species where morphological differentiation is problematic. Molecular techniques also offer a considerable advantage over traditional morphological methods of fruit fly and parasitoid discrimination as well as within-host parasitoid identification, which currently relies on dissection of immature parasitoids from the host, or lengthy and labour-intensive rearing methods. Here we review recent research focusing on the use of molecular strategies for fruit fly and parasitoid detection and differentiation and discuss the implications of these studies on fruit fly management. Insects 2012-08-14 3 3 Review 10.3390/insects3030763 763 788 2075-4450 2012-08-14 doi: 10.3390/insects3030763 Cheryl Jenkins Toni A. Chapman Jessica L. Micallef Olivia L. Reynolds http://www.mdpi.com/2075-4450/3/3/743 Larvae of the tobacco budworm are major polyphagous pests throughout the Americas. Development of effective microbial biopesticides for this and related noctuid pests has been stymied by the natural resistance mediated innate immune response. Hemocytes play an early and central role in activating and coordinating immune responses to entomopathogens. To approach this problem we completed RNA-seq expression profiling of hemocytes collected from larvae following an in vivo challenge with bacterial and fungal cell wall components to elicit an immune response. A de novo exome assembly was constructed by combination of sequence tags from all treatments. Sequence tags from each treatment were aligned separately with the assembly to measure expression. The resulting table of differential expression had > 22,000 assemblies each with a distinct combination of annotation and expression. Within these assemblies > 1,400 were upregulated and > 1,500 downregulated by immune activation with bacteria or fungi. Orthologs to innate immune components of other insects were identified including pattern recognition, signal transduction pathways, antimicrobial peptides and enzymes, melanization and coagulation. Additionally orthologs of components regulating hemocytic functions such as autophagy, apoptosis, phagocytosis and nodulation were identified. Associated cellular oxidative defenses and detoxification responses were identified providing a comprehensive snapshot of the early response to elicitation. Insects 2012-08-14 3 3 Article 10.3390/insects3030743 743 762 2075-4450 2012-08-14 doi: 10.3390/insects3030743 Kent S. Shelby Holly J. R. Popham http://www.mdpi.com/2075-4450/3/3/727 Bactrocera fruit fly species are economically important throughout the Pacific. The USDA, ARS U.S. Pacific Basin Agricultural Research Center has been a world leader in promoting biological control of Bactrocera spp. that includes classical, augmentative, conservation and IPM approaches. In Hawaii, establishment of Bactrocera cucurbitae (Coquillett) in 1895 resulted in the introduction of the most successful parasitoid, Psyttalia fletcheri (Silvestri); similarly, establishment of Bactrocera dorsalis (Hendel) in 1945 resulted in the introduction of 32 natural enemies of which Fopius arisanus (Sonan), Diachasmimorpha longicaudata (Ashmead) and Fopius vandenboschi (Fullaway) were most successful. Hawaii has also been a source of parasitoids for fruit fly control throughout the Pacific region including Australia, Pacific Island Nations, Central and South America, not only for Bactrocera spp. but also for Ceratitis and Anastrepha spp. Most recently, in 2002, F. arisanus was introduced into French Polynesia where B. dorsalis had invaded in 1996. Establishment of D. longicaudata into the new world has been important to augmentative biological control releases against Anastrepha spp. With the rapid expansion of airline travel and global trade there has been an alarming spread of Bactrocera spp. into new areas of the world (i.e., South America and Africa). Results of studies in Hawaii and French Polynesia, support parasitoid introductions into South America and Africa, where B. carambolae and B. invadens, respectively, have become established. In addition, P. fletcheri is a candidate for biological control of B. cucurbitae in Africa. We review past and more recent successes against Bactrocera spp. and related tephritids, and outline simple rearing and release methods to facilitate this goal. Insects 2012-08-10 3 3 Review 10.3390/insects3030727 727 742 2075-4450 2012-08-10 doi: 10.3390/insects3030727 Roger I. Vargas Luc Leblanc Ernest J. Harris Nicholas C. Manoukis http://www.mdpi.com/2075-4450/3/3/719 The Small hive beetle, Aethina tumida, is an invasive pest of honey bees. Indigenous to sub-Saharan Africa, it has now become established in North America and Australia. It represents a serious threat to European honey bees. Commercially available entomopathogenic agents were screened for their potential to control beetle larvae. Entomopathogenic fungi investigated had minimal impact. The nematodes Steinernema kraussei and S. carpocapsae provided excellent control with 100% mortality of larvae being obtained. Sequential applications of the nematodes following larvae entering sand to pupate also provided excellent control for up to 3 weeks. The information gained supports the development of contingency plans to deal with A. tumida should it occur in the UK, and is relevant to the management of Small hive beetle where it is already present. Insects 2012-08-09 3 3 Article 10.3390/insects3030719 719 726 2075-4450 2012-08-09 doi: 10.3390/insects3030719 Andrew G. S. Cuthbertson James J. Mathers Lisa F. Blackburn Michelle E. Powell Gay Marris Stephane Pietravalle Mike A. Brown Giles E. Budge http://www.mdpi.com/2075-4450/3/3/709 An experiment was carried out in order to investigate fungal conidia transmission of Metarhizium anisopliae (Metschnikoff) Sorokin from vector (donor) to healthy Microcerotermes diversus Silvestri (Iso.: Termitidae) and determine the best donor/concentration ratio for transmission. After preliminary trials, concentrations of 3.1 × 104, 3.9 × 105, 3.2 × 106 and 3.5 × 108 conidia mL−1 were selected for testing. The experiment was performed at three donor : Recipient ratios of 10, 30 and 50%. The highest mortality of recipient workers was observed after 14 days at the concentration of 3.5 × 108 conidia mL−1 and donor ratio of 50%. The mortality of recipient workers was less than 20% at all concentrations at a donor ratio of 10%. Our observations indicate social behavior of M. diversus, such as grooming, can be effective in promoting epizootic outbreaks in a colony. While the current results suggest good potential for efficacy, the use of M. anisopliae as a component of integrated pest management of M. diversus still needs to be proven under field conditions. Insects 2012-08-08 3 3 Article 10.3390/insects3030709 709 718 2075-4450 2012-08-08 doi: 10.3390/insects3030709 Amir Cheraghi Behzad Habibpour Mohammad Saied Mossadegh Mona Sharififard http://www.mdpi.com/2075-4450/3/3/692 White grubs are larvae of Coleoptera of the family Scarabaeidae. They are known because of their intensive feeding habits on crop roots. Mallophora ruficauda (Diptera: Asilidae) is a dipteran parasitoid whose larva is a natural enemy for white grubs. This species is a solitary ectoparasitoid, where both female and larva realize different steps in the host location process. Female place its eggs in high grasslands and then, the larva finds and parasitizes the host in the ground. There are nine potential hosts in the area of action of this parasitoid; however a high preference for Cyclocephala signaticollis has been observed (87% of field parasitism). It is known that many insects have developed defensive and immunological mechanisms when attacked by a parasitoid, which can be behavioral, physiological, chemical or genetic. The objectives of this work were to investigate what kind of defense and non-immunological associated mechanisms the white grubs have against this parasitoid and to understand why M. ruficauda have such a high preference for masked chafer grubs or Cyclocephala species. In particular, for each white grub species, we asked: (1) If there is a differential behavioral reaction when a parasitoid attack is simulated; (2) If body attributes of white grubs species have influence on defense behavior, and particularly for the masked chafer C. signaticollis; and (3) Why this species is the most selected by M. ruficauda. It was found that behavioral defenses of white grubs would explain the parasitism pattern of M. ruficauda larvae and its preference for C. signaticollis. Insects 2012-07-26 3 3 Article 10.3390/insects3030692 692 708 2075-4450 2012-07-26 doi: 10.3390/insects3030692 Marcela K. Castelo José E. Crespo http://www.mdpi.com/2075-4450/3/3/668 Ultimately, the success of augmentative fruit fly biological control depends upon the survival, dispersal, attack rate and multi-generational persistence of mass-reared parasitoids in the field. Foraging for hosts, food and mates is fundamental to the above and, at an operational level, the choice of the parasitoid best suited to control a particular tephritid in a certain environment, release rate estimates and subsequent monitoring of effectiveness. In the following we review landscape-level and microhabitat foraging preferences, host/fruit ranges, orientation through environmental cues, host vulnerabilities/ovipositor structures, and inter and intraspecific competition. We also consider tephritid parasitoid mating systems and sexual signals, and suggest the directions of future research. Insects 2012-07-20 3 3 Review 10.3390/insects3030668 668 691 2075-4450 2012-07-20 doi: 10.3390/insects3030668 John Sivinski Martin Aluja http://www.mdpi.com/2075-4450/3/3/653 Studies of predation of ladybird beetles (Coccinellidae) have focused on a limited number of predator taxa, such as birds and ants, while other potential predators have received limited attention. I here consider amphibians as predators of ladybirds. Published amphibian gut analyses show that ladybirds are quite often eaten by frogs and toads (Anura), with recorded frequencies reaching up to 15% of dietary items. Salamanders (Caudata) eat ladybirds less frequently, probably as their habits less often bring them into contact with the beetles. Amphibians do not appear to be deleteriously affected by the potentially toxic alkaloids that ladybirds possess. Amphibians, especially frogs and toads, use primarily prey movement as a release cue to attack their food; it is thus likely that their ability to discriminate against ladybirds and other chemically defended prey is limited. Because of this poor discriminatory power, amphibians have apparently evolved non-specific resistance to prey defensive chemicals, including ladybird alkaloids. Although amphibian-related ladybird mortality is limited, in certain habitats it could outweigh mortality from more frequently studied predators, notably birds. The gut analyses from the herpetological literature used in this study, suggest that in studying predation of insects, entomologists should consider specialized literature on other animal groups. Insects 2012-07-18 3 3 Review 10.3390/insects3030653 653 667 2075-4450 2012-07-18 doi: 10.3390/insects3030653 John J. Sloggett http://www.mdpi.com/2075-4450/3/3/640 In August 2010 the coffee berry borer, Hypothenemus hampei, was first reported to have invaded the Kona coffee growing region of Hawaii, posing a severe economic challenge to the fourth largest agricultural commodity in the State. Despite its long and widespread occurrence throughout the tropics as the most serious pest of coffee, there are still discrepancies in the literature regarding several basic aspects of berry borer biology relevant to its control. In Kona coffee plantations, we investigated the beetles’ response to several trap and lure formulations, and examined the occurrence of beetles in seeds of alternate host plants occurring adjacent to coffee farms. While traps were shown to capture significant numbers of beetles per day, and the occurrence of beetles in alternate hosts was quite rare, the unique situation of coffee culture in Hawaii will make this pest extremely challenging to manage in the Islands. Insects 2012-07-11 3 3 Article 10.3390/insects3030640 640 652 2075-4450 2012-07-11 doi: 10.3390/insects3030640 Russell H. Messing http://www.mdpi.com/2075-4450/3/3/629 Using two-dimensional foraging arenas, laboratory tests were conducted to investigate the effect of soil type, soil moisture level and ambient temperature on the exploratory tunneling by Coptotermes formosanus Shiraki. In choice arenas consisting of two substrate types having two moisture levels each, and conducted at a constant temperature of 22 °C, a significantly greater proportion of termites aggregated in sand than in sandy loam. Similarly, the length of excavated tunnels was also increased in sand. In a given substrate, termite aggregation or tunnel length did not differ between 5% and 15% moisture levels. In no-choice tests, where three different substrates (sand, sandy loam and silt loam) were tested at two temperatures (22 °C and 28 °C), excavations were significantly greater in sand than either sandy loam or silt loam at 22 °C. Fewer primary tunnels were constructed in sandy loam than in sand and fewer branched tunnels than either in sand or silt loam. No significant difference in either tunnel length or number of primary or branched tunnels was found between these two temperatures. Insects 2012-06-27 3 3 Article 10.3390/insects3030629 629 639 2075-4450 2012-06-27 doi: 10.3390/insects3030629 Bal K. Gautam Gregg Henderson http://www.mdpi.com/2075-4450/3/3/616 Basic research on the insect immune response has progressed dramatically within the last two decades, showing that immunity is one of the most effective defenses against foreign invaders. As such, it is important to understand the causes of variation in this response. Here, we investigate the effects of pesticides used in Costa Rican banana plantations on the immune response of the lepidopteran larva, Caligo memnon (Brassolinae). In addition, we performed a parasitism survey of the banana plantations and surrounding forests to provide a broader assessment of pesticide effects on parasitoid populations. All caterpillars for the immune assay were collected from two banana plantations and brought to La Selva Biology Station for immune challenge. Individuals were fed leaves from the plantations (pesticide) or leaves from La Selva (pesticide-free), then immune challenged with injected sephadex beads. We found that individuals feeding on pesticide leaves had significantly lower bead melanization compared to individuals feeding on pesticide-free leaves. Nonetheless, the parasitism survey showed that caterpillars from the banana plantations had lower parasitism rates compared to caterpillars from the La Selva forest. This study adds to the growing body of evidence documenting negative effects of pesticides on the insect immune response and on adult parasitoids, and underscores the need for more research at the intersection between ecological entomology and immunology. Insects 2012-06-27 3 3 Article 10.3390/insects3030616 616 628 2075-4450 2012-06-27 doi: 10.3390/insects3030616 Angela M. Smilanich Lee A. Dyer http://www.mdpi.com/2075-4450/3/3/601 We investigated the effect of the parasitic mite Varroa destructor on the immunological and nutritional condition of honey bees, Apis mellifera, from the perspective of the individual bee and the colony. Pupae, newly-emerged adults and foraging adults were sampled from honey bee colonies at one site in S. Texas, USA. Varroa‑infested bees displayed elevated titer of Deformed Wing Virus (DWV), suggestive of depressed capacity to limit viral replication. Expression of genes coding three anti-microbial peptides (defensin1, abaecin, hymenoptaecin) was either not significantly different between Varroa-infested and uninfested bees or was significantly elevated in Varroa-infested bees, varying with sampling date and bee developmental age. The effect of Varroa on nutritional indices of the bees was complex, with protein, triglyceride, glycogen and sugar levels strongly influenced by life-stage of the bee and individual colony. Protein content was depressed and free amino acid content elevated in Varroa-infested pupae, suggesting that protein synthesis, and consequently growth, may be limited in these insects. No simple relationship between the values of nutritional and immune-related indices was observed, and colony-scale effects were indicated by the reduced weight of pupae in colonies with high Varroa abundance, irrespective of whether the individual pupa bore Varroa. Insects 2012-06-27 3 3 Article 10.3390/insects3030601 601 615 2075-4450 2012-06-27 doi: 10.3390/insects3030601 Katherine A. Aronstein Eduardo Saldivar Rodrigo Vega Stephanie Westmiller Angela E. Douglas http://www.mdpi.com/2075-4450/3/3/593 Indoxacarb (Arilon 20WG) was evaluated against a nuisance pest, the European earwig (Forficula auricularia), and was found to be an effective contact toxicant with residual activity on substrates commonly encountered in urban environments. Within 16 h of being directly sprayed with indoxacarb, ≥90% of earwigs from two populations were either ataxic, moribund, or dead, and 100% displayed these symptoms of severe intoxication at 1 d. Brief exposure (5 min or 1 h) to dried residues on either a porous (pine wood) or non-porous (ceramic tile) substrate also was sufficient to cause severe intoxication of earwigs within 1 d. In all bioassays, indoxacarb-treated earwigs showed no signs of recovery during the 21-d observation period. In outdoor urban habitats, intoxicated earwigs would be more vulnerable to desiccation, predation, or pathogens leading to higher mortality than in a laboratory setting. Insects 2012-06-25 3 3 Article 10.3390/insects3030593 593 600 2075-4450 2012-06-25 doi: 10.3390/insects3030593 Susan C. Jones Joshua L. Bryant http://www.mdpi.com/2075-4450/3/2/573 Specialist and generalist insect herbivore species often differ in how they respond to host plant traits, particularly defensive traits, and these responses can include weakened or strengthened immune responses to pathogens and parasites. Accurate methods to measure immune response in the presence and absence of pathogens and parasites are necessary to determine whether susceptibility to these natural enemies is reduced or increased by host plant traits. Plant chemical traits are particularly important in that host plant metabolites may function as antioxidants beneficial to the immune response, or interfere with the immune response of both specialist and generalist herbivores. Specialist herbivores that are adapted to process and sometimes accumulate specific plant compounds may experience high metabolic demands that may decrease immune response, whereas the metabolic demands of generalist species differ due to more broad-substrate enzyme systems. However, the direct deleterious effects of plant compounds on generalist herbivores may weaken their immune responses. Further research in this area is important given that the ecological relevance of plant traits to herbivore immune responses is equally important in natural systems and agroecosystems, due to potential incompatibility of some host plant species and cultivars with biological control agents of herbivorous pests. Insects 2012-06-19 3 2 Review 10.3390/insects3020573 573 592 2075-4450 2012-06-19 doi: 10.3390/insects3020573 Evan Lampert http://www.mdpi.com/2075-4450/3/2/553 Bacterial endosymbioses are very common in insects and can range from obligate to facultative as well as from mutualistic to pathogenic associations. Several recent studies provide new insight into how endosymbionts manage to establish chronic infections of their hosts without being eliminated by the host immune system. Endosymbiont tolerance may be achieved either by specific bacterial adaptations or by host measurements shielding bacteria from innate defense mechanisms. Nevertheless, insect hosts also need to sustain control mechanisms to prevent endosymbionts from unregulated proliferation. Emerging evidence indicates that in some cases the mutual adaptations of the two organisms may have led to the integration of the endosymbionts as a part of the host immune system. In fact, endosymbionts may provide protective traits against pathogens and predators and may even be required for the proper development of the host immune system during host ontogeny. This review gives an overview of current knowledge of molecular mechanisms ensuring maintenance of chronic infections with mutualistic endosymbionts and the impact of endosymbionts on host immune competence. Insects 2012-06-15 3 2 Review 10.3390/insects3020553 553 572 2075-4450 2012-06-15 doi: 10.3390/insects3020553 Carolin Ratzka Roy Gross Heike Feldhaar http://www.mdpi.com/2075-4450/3/2/538 Several thousand Reticulitermes flavipes (Kollar) including worker, nymph, soldier, neotenic and alate castes were collected from three pine logs brought into the laboratory on dates five years apart. The neotenics, all nymphoid, were divided into three groups based on the extent of cuticle pigmentation and termed regular neotenics (RN), black-headed neotenics (BHN) or black neotenics (BN). All castes, from Log A, in 2008, provided a neutral sex ratio except BHN (N = 378) and BN (N = 51) which were exclusively male while the soldiers (N = 466) were female-biased. This information suggests that there is a sex-linked bifurcation along the path for termite development with a male-biased neotenic or female-biased soldier as the choice. In contrast, termites collected in 2004 from Log B provided sex ratios that included a female biased RN (N = 1017), a neutral soldier (N = 258) and male biased BHN (N = 99) and workers (N = 54). Log C, collected in 2009, provided female biased soldiers (N = 32), RNs (N = 18) and BHNs (N = 4) and only male BN (N = 5). Eight laboratory cultures, ranging in age from five to 14 years old, also were sampled and all castes sexed. The census included a 14-year old queen-right colony, an 8-year old polyandrous colony and six colonies provided nymphs and male-biased worker populations. Together these data indicate a flexible caste determination system providing a unique opportunity for a better understanding of the flexible developmental options available in R. flavipes that we discuss relative to the literature on Reticulitermes ontogeny. Insects 2012-06-04 3 2 Article 10.3390/insects3020538 538 552 2075-4450 2012-06-04 doi: 10.3390/insects3020538 Jian Hu Brian T. Forschler http://www.mdpi.com/2075-4450/3/2/532 Laboratory-made particleboards were tested for their resistance to subterranean termite, Coptotermes curvignathus Holmgren (Order Isoptera, Family Termitidae) by Indonesian standard SNI 01.7207–2006, during four weeks and at the end of the test their mass loss percentage and feeding rate were determined. Particleboards consisted of: jabon (Anthocephalus cadamba, Family Rubiacea) with a density of 0.41 g/cm3; sungkai (Peronema canescens, Family Verbenaceae) with a density of 0.46 g/cm3; mangium (Acacia mangium, Family Rhamnaceae) with a density of 0.60 g/cm3 separately and the three species mixture at a rate of 1:1:1. Densities of the boards were targetted at 0.60 g/cm3 and 0.80 g/cm3 by using 12% urea formaldehyde as binder with 2% paraffin as additive based on oven dry wood particle weight. The hand-formed mats and hot-pressing at 130 °C and 2.45 MPa for 10 min were applied. The results showed that particleboards density did not affect mass loss and feeding rate, but the particleboards made from higher density wood resulted in higher resistance to subterranean termite attack. The most resistant particleboards were made of magium, followed by sungkai, mixed species, and jabon. Insects 2012-05-29 3 2 Article 10.3390/insects3020532 532 537 2075-4450 2012-05-29 doi: 10.3390/insects3020532 Dede Hermawan Yusuf S. Hadi Esi. Fajriani Muhamad Y. Massijaya Nurwati Hadjib http://www.mdpi.com/2075-4450/3/2/511 Arthropod-borne (arbo) viruses are transmitted by vectors, such as mosquitoes, to susceptible vertebrates. Recent research has shown that arbovirus replication and spread in mosquitoes is not passively tolerated but induces host responses to control these pathogens. Small RNA-mediated host responses are key players among these antiviral immune strategies. Studies into one such small RNA-mediated antiviral response, the exogenous RNA interference (RNAi) pathway, have generated a wealth of information on the functions of this mechanism and the enzymes which mediate antiviral activities. However, other small RNA-mediated host responses may also be involved in modulating antiviral activity. The aim of this review is to summarize recent research into the nature of small RNA-mediated antiviral responses in mosquitoes and to discuss future directions for this relatively new area of research. Insects 2012-05-29 3 2 Review 10.3390/insects3020511 511 531 2075-4450 2012-05-29 doi: 10.3390/insects3020511 Claire L. Donald Alain Kohl Esther Schnettler http://www.mdpi.com/2075-4450/3/2/492 Insects, like all invertebrates, express robust innate, but not adaptive, immune reactions to infection and invasion. Insect immunity is usually resolved into three major components. The integument serves as a physical barrier to infections. Within the hemocoel, the circulating hemocytes are the temporal first line of defense, responsible for clearing the majority of infecting bacterial cells from circulation. Specific cellular defenses include phagocytosis, microaggregation of hemocytes with adhering bacteria, nodulation and encapsulation. Infections also stimulate the humoral component of immunity, which involves the induced expression of genes encoding antimicrobial peptides and activation of prophenoloxidase. These peptides appear in the hemolymph of challenged insects 6–12 hours after the challenge. Prostaglandins and other eicosanoids are crucial mediators of innate immune responses. Eicosanoid biosynthesis is stimulated by infection in insects. Inhibition of eicosanoid biosynthesis lethally renders experimental insects unable to clear bacterial infection from hemolymph. Eicosanoids mediate specific cell actions, including phagocytosis, microaggregation, nodulation, hemocyte migration, hemocyte spreading and the release of prophenoloxidase from oenocytoids. Some invaders have evolved mechanisms to suppress insect immunity; a few of them suppress immunity by targeting the first step in the eicosanoid biosynthesis pathways, the enzyme phospholipase A2. We proposed research designed to cripple insect immunity as a technology to improve biological control of insects. We used dsRNA to silence insect genes encoding phospholipase A2, and thereby inhibited the nodulation reaction to infection. The purpose of this article is to place our view of applying dsRNA technologies into the context of eicosanoid actions in insect immunity. The long-term significance of research in this area lies in developing new pest management technologies to contribute to food security in a world with a rapidly growing human population. Insects 2012-05-16 3 2 Review 10.3390/insects3020492 492 510 2075-4450 2012-05-16 doi: 10.3390/insects3020492 David Stanley Eric Haas Jon Miller http://www.mdpi.com/2075-4450/3/2/473 When symbioses between insects and bacteria are discussed, the origin of a given association is regularly of interest. We examined the evolution of the symbiosis between reed beetles (Coleoptera, Chrysomelidae, Donaciinae) and intracellular symbionts belonging to the Enterobacteriaceae. We analyzed the partial sequence of the 16S rRNA to assess the phylogenetic relationships with bacteria we found in other beetle groups (Cerambycidae, Anobiidae, other Chrysomelidae). We discuss the ecology of each association in the context of the phylogenetic analysis. The bacteria in Sagra femorata (Chrysomelidae, Sagrinae) are very closely related to those in the Donaciinae and are located in similar mycetomes. The Sagrinae build a cocoon for pupation like the Donaciinae, in which the bacteria produce the material required for the cocoon. These aspects support the close relationship between Sagrinae and Donaciinae derived in earlier studies and make a common ancestry of the symbioses likely. Using PCR primers specific for fungi, we found Candida sp. in the mycetomes of a cerambycid beetle along with the bacteria. Insects 2012-05-07 3 2 Article 10.3390/insects3020473 473 491 2075-4450 2012-05-07 doi: 10.3390/insects3020473 Gregor Kölsch Dimitra Synefiaridou http://www.mdpi.com/2075-4450/3/2/453 Bark beetle species within the scolytid genera Dendroctonus, Ips, Pityogenes and Tomicus are known to cause extensive ecological and economical damage in spruce and pine forests during epidemic outbreaks all around the world. Dendroctonus ponderosae poses the most recent example having destroyed almost 100,000 km2 of conifer forests in North America. The success and effectiveness of scolytid species lies mostly in strategies developed over the course of time. Among these, a complex system of semiochemicals promotes the communication and aggregation on the spot of infestation facilitating an en masse attack against a host tree’s defenses; or an association with fungi that evolved either in the form of nutrition (ambrosia fungi) or even by reducing the resistance of host trees (blue-stain fungi). Although often specific to a tree genus or species, some bark beetles are polyphagous and have the ability to switch on to new hosts and extend their host range (i.e., between conifer genera such as Pityogenes chalcographus or even from conifer to deciduous trees as Polygraphus grandiclava). A combination of these capabilities in concert with life history or ecological traits explains why bark beetles are considered interesting subjects in evolutionary studies. Several bark beetle species appear in phylogeographic investigations, in an effort to improve our understanding of their ecology, epidemiology and evolution. In this paper investigations that unveil the phylogeographic history of bark beetles are reviewed. A close association between refugial areas and postglacial migration routes that insects and host trees have followed in the last 15,000 BP has been suggested in many studies. Finally, a future perspective of how next generation sequencing will influence the resolution of phylogeographic patterns in the coming years is presented. Utilization of such novel techniques will provide a more detailed insight into the genome of scolytids facilitating at the same time the application of neutral and non-neutral markers. The latter markers in particular promise to enhance the study of eco-physiological reaction types like the so-called pioneer beetles or obligate diapausing individuals. Insects 2012-05-07 3 2 Review 10.3390/insects3020453 453 472 2075-4450 2012-05-07 doi: 10.3390/insects3020453 Dimitrios N. Avtzis Coralie Bertheau Christian Stauffer http://www.mdpi.com/2075-4450/3/2/442 Two established field populations of bed bugs were sampled using host-mimicking traps baited with a combination of CO2, heat and a synthetic kairomone. The proportion of first instar nymphs (between 52% and 78% of all captured insects) was significantly higher than reported in previous studies, which had employed different sampling methods. The proportion of adults was correspondingly much lower than previously reported, between 5% and 7% of total capture. As many as 120 bed bugs were captured in a single trap in one night; the variation in catches between sampling locations within the same room and between days at the same location indicates that multiple nights of trapping may be required to obtain an accurate representation of population structure. Insects 2012-04-30 3 2 Article 10.3390/insects3020442 442 452 2075-4450 2012-04-30 doi: 10.3390/insects3020442 Elizabeth J. Schaafsma Samuel D. Hapke Michael G. Banfield http://www.mdpi.com/2075-4450/3/2/432 Two native, stream-associated amphibians are found in coastal streams of the west coast of North America, the tailed frog and the coastal giant salamander, and each interacts with stream insects in contrasting ways. For tailed frogs, their tadpoles are the primary life stage found in steep streams and they consume biofilm from rock surfaces, which can have trophic and non-trophic effects on stream insects. By virtue of their size the tadpoles are relatively insensitive to stream insect larvae, and tadpoles are capable of depleting biofilm levels directly (exploitative competition), and may also “bulldoze” insect larvae from the surfaces of stones (interference competition). Coastal giant salamander larvae, and sometimes adults, are found in small streams where they prey primarily on stream insects, as well as other small prey. This predator-prey interaction with stream insects does not appear to result in differences in the stream invertebrate community between streams with and without salamander larvae. These two examples illustrate the potential for trophic and non-trophic interactions between stream-associated amphibians and stream insects, and also highlights the need for further research in these systems. Insects 2012-04-10 3 2 Review 10.3390/insects3020432 432 441 2075-4450 2012-04-10 doi: 10.3390/insects3020432 Trisha Atwood John S. Richardson http://www.mdpi.com/2075-4450/3/2/424 Seasonal changes in the popularity of fireflies [usually Genji-fireflies (Luciola cruciata Motschulsky) in Japan] and Japanese rhinoceros beetles [Allomyrina dichotoma (Linne)] were investigated to examine whether contemporary Japanese are interested in visible emergence of these insects as seasonal events. The popularity of fireflies and Japanese rhinoceros beetles was assessed by the Google search volume of their Japanese names, “Hotaru” and “Kabuto-mushi” in Japanese Katakana script using Google Trends. The search volume index for fireflies and Japanese rhinoceros beetles was distributed across seasons with a clear peak in only particular times of each year from 2004 to 2011. In addition, the seasonal peak of popularity for fireflies occurred at the beginning of June, whereas that for Japanese rhinoceros beetles occurred from the middle of July to the beginning of August. Thus seasonal peak of each species coincided with the peak period of the emergence of each adult stage. These findings indicated that the Japanese are interested in these insects primarily during the time when the two species are most visibly abundant. Although untested, this could suggest that fireflies and Japanese rhinoceros beetles are perceived by the general public as indicators or symbols of summer in Japan. Insects 2012-04-10 3 2 Article 10.3390/insects3020424 424 431 2075-4450 2012-04-10 doi: 10.3390/insects3020424 Kenta Takada http://www.mdpi.com/2075-4450/3/2/410 The relationship between mosquitoes and their amphibian hosts is a unique, reciprocal trophic interaction. Instead of a one-way, predator-prey relationship, there is a cyclical dance of avoidance and attraction. This has prompted spatial and temporal synchrony between organisms, reflected in emergence time of mosquitoes in the spring and choice of habitat for oviposition. Frog-feeding mosquitoes also possess different sensory apparatuses than do their mammal-feeding counterparts. The reciprocal nature of this relationship is exploited by various blood parasites that use mechanical, salivary or trophic transmission to pass from mosquitoes to frogs. It is important to investigate the involvement of mosquitoes, frogs and parasites in this interaction in order to understand the consequences of anthropogenic actions, such as implementing biocontrol efforts against mosquitoes, and to determine potential causes of the global decline of amphibian species. Insects 2012-04-03 3 2 Review 10.3390/insects3020410 410 423 2075-4450 2012-04-03 doi: 10.3390/insects3020410 Laura V. Ferguson Todd G. Smith http://www.mdpi.com/2075-4450/3/2/402 Bed bug (Cimex lectularius L.) infestations are currently controlled by a variety of non-chemical and chemical methods. There have been few studies on the comparative effectiveness of these control techniques. We evaluated three bed bug management strategies in an apartment building: (1) non-chemical methods only (n = 9); (2) insecticides only (n = 6); and (3) integrated pest management including both non-chemical methods and insecticides (n = 9). The apartments were one-bedroom units occupied by seniors or people with disabilities. Bed bug numbers in each apartment were determined by visual inspection and/or installing intercepting devices under bed and sofa legs. The median (min, max) bed bug counts in the non-chemical methods only, insecticides only, and integrated pest management (IPM) treatment were: 4 (1, 57), 19 (1, 250), and 14 (1, 219), respectively prior to the treatments. The apartments were retreated if found necessary during biweekly to monthly inspections. After 10 weeks, bed bugs were found to be eliminated from 67, 33, and 44% of the apartments in the three treatment groups, respectively. The final (after 10 weeks) median (min, max) bed bug counts in the non-chemical methods only, insecticides only, and IPM treatment were: 0 (0, 134), 11.5 (0, 58), and 1 (0, 38), respectively. There were no significant differences in the speed of bed bug count reduction or the final bed bug counts. Lack of resident cooperation partially contributed to the failure in eliminating bed bugs from some of the apartments. Results of this study suggest that non-chemical methods can effectively eliminate bed bugs in lightly infested apartments. Insects 2012-04-02 3 2 Article 10.3390/insects3020402 402 409 2075-4450 2012-04-02 doi: 10.3390/insects3020402 Changlu Wang Kurt Saltzmann Gary Bennett Timothy Gibb http://www.mdpi.com/2075-4450/3/2/396 Standardized laboratory testing of wood and wood-based products against subterranean termites in Indonesia (SNI 01.7207-2006) (SNI) has no requirement for the inclusion of a comparative reference species of wood (reference control). This is considered a weakness of the Indonesian standard. Consequently, a study was undertaken to identify a suitable Indonesian species of community wood that could be used as a reference control. Four candidate species of community woods: Acacia mangium, Hevea brasiliensis, Paraserianthes falcataria and Pinus merkusii were selected for testing their susceptibility to feeding by Coptotermes formosanus. Two testing methods (SNI and the Japanese standard method JIS K 1571-2004) were used to compare the susceptibility of each species of wood. Included in the study was Cryptomeria japonica, the reference control specified in the Japanese standard. The results of the study indicated that P. merkusii is a suitable reference species of wood for inclusion in laboratory tests against subterranean termites, conducted in accordance with the Indonesian standard (SNI 01.7207-2006). Insects 2012-03-28 3 2 Article 10.3390/insects3020396 396 401 2075-4450 2012-03-28 doi: 10.3390/insects3020396 Arinana Kunio Tsunoda Elis N. Herliyana Yusuf S. Hadi http://www.mdpi.com/2075-4450/3/2/390 The effects of thermal modification on the resistance of Dendrocalamus asper against Microcerotermes losbañosensis were investigated after exposure to virgin coconut oil at 140–200 °C for 30–120 min. The results showed that heat treatment significantly improved bamboo’s resistance to termites based on mass losses and visual observations. The enhancement was highest at 200 °C. Prolonged treatment had a positive effect on the resistance at lower temperatures only. Insects 2012-03-27 3 2 Article 10.3390/insects3020390 390 395 2075-4450 2012-03-27 doi: 10.3390/insects3020390 Ronniel D. Manalo Carlos M. Garcia http://www.mdpi.com/2075-4450/3/2/378 We determined virulence of seven Heterorhabditis bacteriophora strain GPS11 inbred lines possessing superior infective juvenile longevity, and heat and ultra violet radiation tolerance against white grubs Popillia japonica and Cyclocephala borealis. At 1 and 2 weeks after treatment, inbred line A2 was significantly more virulent towards P. japonica compared to the parent strain GPS11 and inbred lines A7, A8, A12 and A21; and line A2 caused significantly higher C. borealis mortality than lines A6 and A12. Penetration, encapsulation and survival of two inbred lines, A2 and A12, that showed the highest and lowest virulence against both grub species were then assessed. There were no differences between the two lines for the total number of nematodes penetrated in either P. japonica or C. borealis within the first 24 h, but a significantly higher percentage of penetrated nematodes were alive in line A2 compared to the line A12 in both grub species. P. japonica immune response over time to hemocoel-injected nematodes of A2, A12 and the parent strain was further investigated. While all injected nematodes were encapsulated at 6 h post injection, non-encapsulated living nematodes were detected at 12 and 24 h post injection, showing the breakage out of encapsulation. A higher percentage of non-encapsulated living nematodes and a lower percentage of dead nematodes were found in line A2 as compared to the line A12 after 12 h post injection. These data suggest that virulence differences in the studied H. bacteriophora inbred lines are not due to differences in nematode penetration or recognition by the grub immune system, but are related to the ability of the infective juveniles to break out of encapsulation. Insects 2012-03-23 3 2 Article 10.3390/insects3020378 378 389 2075-4450 2012-03-23 doi: 10.3390/insects3020378 Ruisheng An Marcio Voss Ganpati B. Jagdale Parwinder S. Grewal http://www.mdpi.com/2075-4450/3/2/367 This study examines the individual behavior of workers of the Formosan subterranean termite, Coptotermes formosanus Shirkai, on two consecutive days of tunnel construction. In each trial, a group of 30 termite workers was observed continuously during the first 60 min of construction of a new tunnel on two consecutive days. On each day, an average of 68% of individuals did not participate in tunnel construction, 19% spent < 25 min tunneling, and 13% spent ≥ 25 min tunneling. There were specific individuals that did most of the work in the construction of new tunnels on both days. An individual that spent at least 25 min tunneling on Day 1 was significantly more likely to spend at least 25 min tunneling on Day 2 than individuals that spent < 25 min tunneling on Day 1. When individuals were ranked based on the time spent tunneling on Day 1 and Day 2, there were individuals ranked as one of the top four excavators on both days in three of the four groups. These results indicate that there is evidence of task allocation by termite workers during the construction of a new tunnel. Insects 2012-03-23 3 2 Article 10.3390/insects3020367 367 377 2075-4450 2012-03-23 doi: 10.3390/insects3020367 Mary L. Cornelius http://www.mdpi.com/2075-4450/3/1/339 Ectosymbioses among bark beetles (Curculionidae, Scolytinae) and fungi (primarily ophiostomatoid Ascomycetes) are widespread and diverse. Associations range from mutualistic to commensal, and from facultative to obligate. Some fungi are highly specific and associated only with a single beetle species, while others can be associated with many. In addition, most of these symbioses are multipartite, with the host beetle associated with two or more consistent partners. Mycangia, structures of the beetle integument that function in fungal transport, have evolved numerous times in the Scolytinae. The evolution of such complex, specialized structures indicates a high degree of mutual dependence among the beetles and their fungal partners. Unfortunately, the processes that shaped current day beetle-fungus symbioses remain poorly understood. Phylogeny, the degree and type of dependence on partners, mode of transmission of symbionts (vertical vs. horizontal), effects of the abiotic environment, and interactions among symbionts themselves or with other members of the biotic community, all play important roles in determining the composition, fidelity, and longevity of associations between beetles and their fungal associates. In this review, I provide an overview of these associations and discuss how evolution and ecological processes acted in concert to shape these fascinating, complex symbioses. Insects 2012-03-22 3 1 Review 10.3390/insects3010339 339 366 2075-4450 2012-03-22 doi: 10.3390/insects3010339 Diana L. Six http://www.mdpi.com/2075-4450/3/1/324 Juvenile hormone (JH) is responsible for controlling many biological processes. In several insect species JH has been implicated as a key regulator of developmental timing, preventing the premature onset of metamorphosis during larval growth periods. However, the molecular basis of JH action is not well-understood. In this review, we highlight recent advances which demonstrate the importance of transcription factors from the bHLH-PAS and nuclear receptor families in mediating the response to JH. Insects 2012-03-22 3 1 Review 10.3390/insects3010324 324 338 2075-4450 2012-03-22 doi: 10.3390/insects3010324 Travis J. Bernardo Edward B. Dubrovsky http://www.mdpi.com/2075-4450/3/1/307 We present a new perspective for the role of Termitomyces fungi in the mutualism with fungus-growing termites. According to the predominant view, this mutualism is as an example of agriculture with termites as farmers of a domesticated fungus crop, which is used for degradation of plant-material and production of fungal biomass. However, a detailed study of the literature indicates that the termites might as well be envisioned as domesticates of the fungus. According to the “ruminant hypothesis” proposed here, termite workers, by consuming asexual fruiting bodies not only harvest asexual spores, but also lignocellulolytic enzymes, which they mix with foraged plant material and enzymes of termite and possibly bacterial origin. This mixture is the building material of the fungus garden and facilitates efficient degradation of plant material. The fungus garden thus functions as an external rumen for termites and primarily the fungi themselves benefit from their own, and gut-derived, lignocellulolytic enzymes, using the termites to efficiently mix these with their growth substrate. Only secondarily the termites benefit, when they consume the degraded, nitrogen-enriched plant-fungus mixture a second time. We propose that the details of substrate use, and the degree of complementarity and redundancy among enzymes in food processing, determine selection of horizontally transmitted fungal symbionts at the start of a colony: by testing spores on a specific, mechanically and enzymatically pre-treated growth substrate, the termite host has the opportunity to select specific fungal symbionts. Potentially, the gut-microbiota thus influence host-fungus specificity, and the selection of specific fungal strains at the start of a new colony. We argue that we need to expand the current bipartite insect-biased view of the mutualism of fungus-growing termites and include the possible role of bacteria and the benefit for the fungi to fully understand the division of labor among partners in substrate degradation. Insects 2012-03-16 3 1 Communication 10.3390/insects3010307 307 323 2075-4450 2012-03-16 doi: 10.3390/insects3010307 Tânia Nobre Duur K. Aanen http://www.mdpi.com/2075-4450/3/1/295 Bacterial interactions with eukaryotic hosts are complex processes which vary from pathogenic to mutualistic. Identification of bacterial genes differentially expressed in the host, promises to unravel molecular mechanisms driving and maintaining such interactions. Several techniques have been developed in the past 20 years to investigate bacterial gene expression within their hosts. The most commonly used techniques include in-vivo expression technology, signature-tagged mutagenesis, differential fluorescence induction, and cDNA microarrays. However, the limitations of these techniques in analyzing bacterial in-vivo gene expression indicate the need to develop alternative tools. With many advantages over the other methods for analyzing bacterial in-vivo gene expression, selective capture of transcribed sequences (SCOTS) technique has the prospect of becoming an elegant tool for discovery of genes involved in the bacterium-host interaction. Here, we summarize the advances in SCOTS technique, including its current and potential applications in bacterial gene expression studies under a variety of conditions from in-vitro to in-vivo and from mammals to insects. Insects 2012-03-02 3 1 Review 10.3390/insects3010295 295 306 2075-4450 2012-03-02 doi: 10.3390/insects3010295 Ruisheng An Parwinder S. Grewal http://www.mdpi.com/2075-4450/3/1/270 The interaction between physiogeographic landscape context and certain life history characteristics, particularly dispersal ability, can generate predictable outcomes for how species responded to Pleistocene (and earlier) climatic changes. Furthermore, the extent to which impacts of past landscape-level changes ‘scale-up’ to whole communities has begun to be addressed via comparative phylogeographic analyses of co-distributed species. Here we present an overview of a body of research on flightless low-mobility forest invertebrates, focusing on two springtails and two terrestrial flatworms, from Tallaganda on the Great Dividing Range of south-eastern Australia. These species are distantly-related, and represent contrasting trophic levels (i.e., slime-mold-grazers vs. higher-level predators). However, they share an association with the dead wood (saproxylic) habitat. Spatial patterns of intraspecific genetic diversity partly conform to topography-based divisions that circumscribe five ‘microgeographic regions’ at Tallaganda. In synthesizing population processes and past events that generated contemporary spatial patterns of genetic diversity in these forest floor invertebrates, we highlight cases of phylogeographic congruence, pseudo-congruence, and incongruence. Finally, we propose conservation-oriented recommendations for the prioritisation of areas for protection. Insects 2012-02-29 3 1 Review 10.3390/insects3010270 270 294 2075-4450 2012-02-29 doi: 10.3390/insects3010270 Ryan C. Garrick David M. Rowell Paul Sunnucks http://www.mdpi.com/2075-4450/3/1/262 It has long been known that armored scale insects harbor endosymbiotic bacteria inside specialized cells called bacteriocytes. Originally, these endosymbionts were thought to be fungal symbionts but they are now known to be bacterial and have been named Uzinura diaspidicola. Bacteriocyte and endosymbiont distribution patterns within host insects were visualized using in situ hybridization via 16S rRNA specific probes. Images of scale insect embryos, eggs and adult scale insects show patterns of localized bacteriocytes in embryos and randomly distributed bacteriocytes in adults. The symbiont pocket was not found in the armored scale insect eggs that were tested. The pattern of dispersed bacteriocytes in adult scale insects suggest that Uzinura and Blattabacteria may share some homologous traits that coincide with similar life style requirements, such as dispersal in fat bodies and uric acid recycling. Insects 2012-02-29 3 1 Article 10.3390/insects3010262 262 269 2075-4450 2012-02-29 doi: 10.3390/insects3010262 Matthew E. Gruwell Meghan Flarhety Katharina Dittmar http://www.mdpi.com/2075-4450/3/1/246 Vertically acquired, endosymbiotic bacteria such as those belonging to the Rickettsiales and the Mollicutes are known to influence the biology of their arthropod hosts in order to favour their own transmission. In this study we investigate the influence of such reproductive parasites on the behavior of their insects and arachnid hosts. We find that changes in host behavior that are associated with endosymbiont infections are not restricted to characteristics that are directly associated with reproduction. Other behavioural traits, such as those involved in intraspecific competition or in dispersal may also be affected. Such behavioural shifts are expected to influence the level of intraspecific variation and the rate at which adaptation can occur through their effects on effective population size and gene flow amongst populations. Symbionts may thus influence both levels of polymorphism within species and the rate at which diversification can occur. Insects 2012-02-29 3 1 Review 10.3390/insects3010246 246 261 2075-4450 2012-02-29 doi: 10.3390/insects3010246 Sara L. Goodacre Oliver Y. Martin http://www.mdpi.com/2075-4450/3/1/228 The possible roles played by yeasts in attine ant nests are mostly unknown. Here we present our investigations on the plant polysaccharide degradation profile of 82 yeasts isolated from fungus gardens of Atta and Acromyrmex species to demonstrate that yeasts found in ant nests may play the role of making nutrients readily available throughout the garden and detoxification of compounds that may be deleterious to the ants and their fungal cultivar. Among the yeasts screened, 65% exhibited cellulolytic enzymes, 44% exhibited pectinolytic activity while 27% and 17% possess enzyme systems for the degradation of protease and amylase, respectively. Galacturonic acid, which had been reported in previous work to be poorly assimilated by the ant fungus and also to have a negative effect on ants’ survival, was assimilated by 64% and 79% of yeasts isolated from nests of A. texana and Acromyrmex respectively. Our results suggest that yeasts found in ant nests may participate in generation of nutrients and removal of potentially toxic compounds, thereby contributing to the stability of the complex microbiota found in the leaf-cutting ant nests. Insects 2012-02-17 3 1 Article 10.3390/insects3010228 228 245 2075-4450 2012-02-17 doi: 10.3390/insects3010228 Thais D. Mendes André Rodrigues Ifeloju Dayo-Owoyemi Fernando A. L. Marson Fernando C. Pagnocca http://www.mdpi.com/2075-4450/3/1/200 Bark beetles (Coleoptera, Scolytinae) have a widespread association with fungi, especially with ophiostomatoid fungi (Ascomycota) that cause blue staining of wood, and in some cases, serious tree diseases. In Fennoscandia, most studies of these fungi have focused on economically important bark beetle species and this is likely to have led to a biased view of the fungal biodiversity in the region. Recently, the associations between fungi and bark beetles in Fennoscandia have been shown to be more diverse than previously thought. Furthermore, they form complex and dynamic associations that are only now beginning to emerge. This review examines the current knowledge of the rather poorly known interactions between bark beetles, fungi and their conifer host trees in Fennoscandia. The diversity of ophiostomatoid species is discussed and the possible factors that influence the assemblages of fungal associates are considered for all species that are known to occur in the region. For many ophiostomatoid species found in Fennoscandia, little or nothing is known regarding their pathogenicity, particularly if they were to be transferred to new environments. We, therefore, draw attention to the possible threats of timber trade and climate change-induced invasions of new habitats by bark beetles and the fungi that can be moved along with them. Insects 2012-02-15 3 1 Review 10.3390/insects3010200 200 227 2075-4450 2012-02-15 doi: 10.3390/insects3010200 Riikka Linnakoski Z. Wilhelm de Beer Pekka Niemelä Michael J. Wingfield http://www.mdpi.com/2075-4450/3/1/161 The sex-determining systems of arthropods are surprisingly diverse. Some species have male or female heterogametic sex chromosomes while other species do not have sex chromosomes. Most species are diploids but some species, including wasps, ants, thrips and mites, are haplodiploids (n in males; 2n in females). Many of the sexual aberrations, such as sexual mosaics, sex-specific lethality and conversion of sexuality, can be explained by developmental defects including double fertilization of a binucleate egg, loss of a sex chromosome or perturbation of sex-determining gene expression, which occur accidentally or are induced by certain environmental conditions. However, recent studies have revealed that such sexual aberrations can be caused by various groups of vertically-transmitted endosymbiotic microbes such as bacteria of the genera Wolbachia, Rickettsia, Arsenophonus, Spiroplasma and Cardinium, as well as microsporidian protists. In this review, we first summarize the accumulated data on endosymbiont-induced sexual aberrations, and then discuss how such endosymbionts affect the developmental system of their hosts and what kinds of ecological and evolutionary effects these endosymbionts have on their host populations. Insects 2012-02-10 3 1 Review 10.3390/insects3010161 161 199 2075-4450 2012-02-10 doi: 10.3390/insects3010161 Daisuke Kageyama Satoko Narita Masaya Watanabe http://www.mdpi.com/2075-4450/3/1/141 Culture-independent analysis of the gut of a wood-boring insect, Anoplophora glabripennis (Coleoptera: Cerambycidae), revealed a consistent association between members of the fungal Fusarium solani species complex and the larval stage of both colony-derived and wild A. glabripennis populations. Using the translation elongation factor 1-alpha region for culture-independent phylogenetic and operational taxonomic unit (OTU)-based analyses, only two OTUs were detected, suggesting that genetic variance at this locus was low among A. glabripennis-associated isolates. To better survey the genetic variation of F. solani associated with A. glabripennis, and establish its phylogenetic relationship with other members of the F. solani species complex, single spore isolates were created from different populations and multi-locus phylogenetic analysis was performed using a combination of the translation elongation factor alpha-1, internal transcribed spacer, and large subunit rDNA regions. These analyses revealed that colony-derived larvae reared in three different tree species or on artificial diet, as well as larvae from wild populations collected from three additional tree species in New York City and from a single tree species in Worcester, MA, consistently harbored F. solani within their guts. While there is some genetic variation in the F. solani carried between populations, within-population variation is low. We speculate that F. solani is able to fill a broad niche in the A. glabripennis gut, providing it with fungal lignocellulases to allow the larvae to grow and develop on woody tissue. However, it is likely that many F. solani genotypes could potentially fill this niche, so the relationship may not be limited to a single member of the F. solani species complex. While little is known about the role of filamentous fungi and their symbiotic associations with insects, this report suggests that larval A. glabripennis has developed an intimate relationship with F. solani that is not limited by geographic location or host tree. Insects 2012-02-10 3 1 Article 10.3390/insects3010141 141 160 2075-4450 2012-02-10 doi: 10.3390/insects3010141 Scott M. Geib Erin D. Scully Maria del Mar Jimenez-Gasco John E. Carlson Ming Tien Kelli Hoover http://www.mdpi.com/2075-4450/3/1/133 This study evaluated foraging effectiveness of Pacific cicada killers (Sphecius convallis) by comparing observed prey loads to that predicted by an optimality model. Female S. convallis preyed exclusively on the cicada Tibicen parallelus, resulting in a mean loaded flight muscle ratio (FMR) of 0.187 (N = 46). This value lies just above the marginal level, and only seven wasps (15%) were below 0.179. The low standard error (0.002) suggests that S. convallis is the most ideal flying predator so far examined in this respect. Preying on a single species may have allowed stabilizing selection to adjust the morphology of females to a nearly ideal size. That the loaded FMR is slightly above the marginal level may provide a small safety factor for wasps that do not have optimal thorax temperatures or that have to contend with attempted prey theft. Operational FMR was directly related to wasp body mass. Smaller wasps were overloaded in spite of provisioning with smaller cicadas, while larger wasps were underloaded despite provisioning with larger cicadas. Small wasps may have abandoned larger cicadas because of difficulty with carriage. Insects 2012-02-10 3 1 Article 10.3390/insects3010133 133 140 2075-4450 2012-02-10 doi: 10.3390/insects3010133 Joseph R. Coelho Jon M. Hastings Charles W. Holliday http://www.mdpi.com/2075-4450/3/1/131 Following publication of our article [1], we found errors in Table 4b. These errors do not make any difference to the main findings and conclusions reported in our paper. The numbers in the column for the range of mean ± 1 standard deviation for hind wings were incorrect. We wish to apologize for the mistake made and inconveniences caused. [...] Insects 2012-02-03 3 1 Correction 10.3390/insects3010131 131 132 2075-4450 2012-02-03 doi: 10.3390/insects3010131 Su Yee Lim Brian T. Forschler http://www.mdpi.com/2075-4450/3/1/120 Ants often form mutualistic interactions with aphids, soliciting honeydew in return for protective services. Under certain circumstances, however, ants will prey upon aphids. In addition, in the presence of ants aphids may increase the quantity or quality of honeydew produced, which is costly. Through these mechanisms, ant attendance can reduce aphid colony growth rates. However, it is unknown whether demand from within the ant colony can affect the ant-aphid interaction. In a factorial experiment, we tested whether the presence of larvae in Lasius niger ant colonies affected the growth rate of Aphis fabae colonies. Other explanatory variables tested were the origin of ant colonies (two separate colonies were used) and previous diet (sugar only or sugar and protein). We found that the presence of larvae in the ant colony significantly reduced the growth rate of aphid colonies. Previous diet and colony origin did not affect aphid colony growth rates. Our results suggest that ant colonies balance the flow of two separate resources from aphid colonies- renewable sugars or a protein-rich meal, depending on demand from ant larvae within the nest. Aphid payoffs from the ant-aphid interaction may change on a seasonal basis, as the demand from larvae within the ant colony waxes and wanes. Insects 2012-02-02 3 1 Article 10.3390/insects3010120 120 130 2075-4450 2012-02-02 doi: 10.3390/insects3010120 Tom H. Oliver Simon R. Leather James M. Cook http://www.mdpi.com/2075-4450/3/1/91 Symbiosis is a common phenomenon in which associated organisms can cooperate in ways that increase their ability to survive, reproduce, or utilize hostile environments. Here, we discuss polydnavirus symbionts of parasitic wasps. These viruses are novel in two ways: (1) they have become non-autonomous domesticated entities that cannot replicate outside of wasps; and (2) they function as a delivery vector of genes that ensure successful parasitism of host insects that wasps parasitize. In this review we discuss how these novelties may have arisen, which genes are potentially involved, and what the consequences have been for genome evolution. Insects 2012-01-31 3 1 Review 10.3390/insects3010091 91 119 2075-4450 2012-01-31 doi: 10.3390/insects3010091 Gaelen R. Burke Michael R. Strand http://www.mdpi.com/2075-4450/3/1/62 Reticulitermes nelsonae, a new species of Rhinotermitidae (Isoptera) is described based on specimens from Sapelo Island, GA, Thomasville, GA, Havelock, NC, and Branford, FL. Adult (alate) and soldier forms are described. Diagnostic characters are provided and incorporated into a supplemental couplet of a dichotomous key to the known species of Reticulitermes found in Georgia, USA. Insects 2012-01-06 3 1 Article 10.3390/insects3010062 62 90 2075-4450 2012-01-06 doi: 10.3390/insects3010062 Su Yee Lim Brian T. Forschler http://www.mdpi.com/2075-4450/3/1/41 Fungus-growing ants gain access to nutrients stored in plant biomass through their association with a mutualistic fungus they grow for food. This 50 million-year-old obligate mutualism likely facilitated some of these species becoming dominant Neotropical herbivores that can achieve immense colony sizes. Recent culture-independent investigations have shed light on the conversion of plant biomass into nutrients within ant fungus gardens, revealing that this process involves both the fungal cultivar and a symbiotic community of bacteria including Enterobacter, Klebsiella, and Pantoea species. Moreover, the genome sequences of the leaf-cutter ants Atta cephalotes and Acromyrmex echinatior have provided key insights into how this symbiosis has shaped the evolution of these ants at a genetic level. Here we summarize the findings of recent research on the microbial community dynamics within fungus-growing ant fungus gardens and discuss their implications for this ancient symbiosis. Insects 2012-01-06 3 1 Review 10.3390/insects3010041 41 61 2075-4450 2012-01-06 doi: 10.3390/insects3010041 Frank O. Aylward Cameron R. Currie Garret Suen http://www.mdpi.com/2075-4450/3/1/25 Twenty-one boards infested with drywood termites were examined for activity using a Termatrac® motion detector. Termite galleries were identified using a Resistograph drill and treated with one of three ready-to-use (RTU) products. Results indicated that the Termatrac was excellent at locating termite activity but provided 9.5% false negatives. The Resistograph located termite galleries with an average of 4.6 ± 2.7 holes drilled to find at least one gallery in a board. Treatments included three formulations and two active ingredients; a foam (imidacloprid), a dry (fipronil) and an experimental formulation in a pressurized can (fipronil). All treatments provided evidence for a reduction in mean termite populations per board compared to the control. Two treatments provided evidence of elimination of infestation but no formulation eliminated infestations in every board that was treated. The concept of local treatment for drywood termite control is discussed relative to our results. Insects 2012-01-03 3 1 Article 10.3390/insects3010025 25 40 2075-4450 2012-01-03 doi: 10.3390/insects3010025 Robert Hickman Brian T. Forschler http://www.mdpi.com/2075-4450/3/1/18 The resistance of yemane (Gmelina arborea Roxb.)-based wood wool cement board (WWCB) against Philippine termites was evaluated under laboratory and field conditions. Tests were conducted following the FPRDI standard procedures in determining the resistance of WWCB against subterranean and drywood termites. Results of the laboratory tests showed that WWCB was resistant to both Microcerotermes losbañosensis Oshima and Cryptotermes dudleyi Banks. Under field conditions, WWCB was highly resistant to subterranean termites. There was no remarkable termite damage except for the normal nibbling or initial termite feeding on the board during the 8-year exposure period. Insects 2011-12-28 3 1 Article 10.3390/insects3010018 18 24 2075-4450 2011-12-28 doi: 10.3390/insects3010018 Carlos M. Garcia Dwight A. Eusebio Marciana R. San Pablo Edgar M. Villena http://www.mdpi.com/2075-4450/3/1/1 A majority of humans spend their waking hours surrounded by insects, so it should be no surprise that insects also appear in humans’ dreams as we sleep. Dreaming about insects has a peculiar history, marked by our desire to explain a dream’s significance and by the tactic of evoking emotions by injecting insects in dream-related works of art, film, music, and literature. I surveyed a scattered literature for examples of insects in dreams, first from the practices of dream interpretation, psychiatry, and scientific study, then from fictional writings and popular culture, and finally in the etymology of entomology by highlighting insects with dream-inspired Latinate names. A wealth of insects in dreams, as documented clinically and culturally, attests to the perceived relevance of dreams and to the ubiquity of insects in our lives. Insects 2011-12-21 3 1 Article 10.3390/insects3010001 1 17 2075-4450 2011-12-21 doi: 10.3390/insects3010001 Barrett A. Klein http://www.mdpi.com/2075-4450/2/4/564 During the past decade a few artists and even fewer entomologists discovered flatbed scanning technology, using extreme resolution graphical arts scanners for acquiring high magnification digital images of plants, animals and inanimate objects. They are not just for trip receipts anymore. The special attributes of certain scanners, to image thick objects is discussed along with the technical features of the scanners including magnification, color depth and shadow detail. The work of pioneering scanner artist, Joseph Scheer from New York’s Alfred University is highlighted. Representative flatbed-scanned images of moths are illustrated along with techniques to produce them. Collecting and preparing moths, and other objects, for scanning are described. Highlights of the Fulbright sabbatical year of professor Scheer in Arizona and Sonora, Mexico are presented, along with comments on moths in science, folklore, art and pop culture. The use of flatbed scanners is offered as a relatively new method for visualizing small objects while acquiring large files for creating archival inkjet prints for display and sale. Insects 2011-12-14 2 4 Article 10.3390/insects2040564 564 583 2075-4450 2011-12-14 doi: 10.3390/insects2040564 Stephen L. Buchmann http://www.mdpi.com/2075-4450/2/4/555 Activity of colonies of the western drywood termite, Incisitermes minor, was measured with acoustic emission (AE) technology in five loquat (Eriobotrya japonica) logs. Termite activity, whether it was feeding, excavation or movement, was monitored for 11 months under ambient conditions in a small wooden structure maintained at the University of California Richmond Field Station. AE, temperature, and humidity data were measured in 3-minute increments. Termite activity was greater during the warmer summer months compared to the cooler winter months. Termites in all five logs displayed a similar daily cycle of activity, peaking in the late afternoon. Seasonal and daily fluctuations in termite activity were significantly associated with temperature, whereas humidity did not appear to have a noticeable effect on termite activity. Possible mechanisms that drive the seasonal and daily cycles in termite activity, as measured by AE technology, and the possible implications for inspections and post-treatment analysis are discussed. Insects 2011-12-12 2 4 Article 10.3390/insects2040555 555 563 2075-4450 2011-12-12 doi: 10.3390/insects2040555 Vernard Lewis Shawn Leighton Robin Tabuchi Michael Haverty http://www.mdpi.com/2075-4450/2/4/540 The present paper reviews the biology of reed beetles (Donaciinae), presents experimental data on the role of specific symbiotic bacteria, and describes a molecular method for the detection of those bacteria. Reed beetles are herbivores living on wetland plants, each species being mono- or oligo-phagous. They lay their eggs on the host plant and the larvae live underwater in the sediment attached to its roots. The larvae pupate there in a water-tight cocoon, which they build using a secretion that is produced by symbiotic bacteria. The bacteria are located in four blind sacs at the foregut of the larvae; in (female) adults they colonize two out of the six Malpighian tubules. Tetracycline treatment of larvae reduced their pupation rate, although the bacteria could not be fully eliminated. When the small amount of bacterial mass attached to eggs was experimentally removed before hatching, symbiont free larvae resulted, showing the external transmission of the bacteria to the offspring. Specific primers were designed to detect the bacteria, and to confirm their absence in manipulated larvae. The pupation underwater enabled the reed beetles to permanently colonize the wetlands and to diversify in this habitat underexploited by herbivorous insects (adaptive radiation). Insects 2011-12-09 2 4 Article 10.3390/insects2040540 540 554 2075-4450 2011-12-09 doi: 10.3390/insects2040540 Birgit Kleinschmidt Gregor Kölsch http://www.mdpi.com/2075-4450/2/4/532 With the advancement from natural pyrethrins to synthetic pyrethroids, their applications have expanded from household insecticides for indoor use against sanitary pests to outdoor use for agriculture, forestry, animal health, termite control, and many other pest situations. However, high fish toxicity and development of pyrethroid resistance in some pests have been cited as common shortcomings of pyrethroids. To overcome these pyrethroid problems such as high fish toxicity, Katsuda and fellow scientists invented silafluofen by introducing a silicone atom into the pyrethroidal chemical structure in 1984. In addition to the high insecticidal activity and low mammalian toxicity, this compound features low fish toxicity, chemical stability under sunlight, in the soil and under alkaline environments. These features make silafluofen unique among pyrethroids. In Japan, silafluofen has been used as an agricultural insecticide for 15 years since 1995 for various plants, especially useful for paddy rice protection because of its low fish toxicity. Over the last 20 years, silafluofen-based termiticides including emulsifiable concentrate (EC) and oil formulations have been widely used in Japan for soil treatment and timber treatments. Additional silafluofen product lines include anti-termitic plastic sheets which are laid under buildings. In this paper, literature on the development of silafluofen and its use in Japan are reviewed. On the other hand, in Thailand, we proceeded with development works of silafluofen-based termiticides from 2005 by starting laboratory efficacy tests and field efficacy tests in Phuket. Both laboratory and field tests showed good efficacy as a soil termiticide, suggesting that the material will perform well for commercial use in high biological hazard environments such as Thailand and can be used in environments close to water where fish toxicity might be a concern with other pyrethroids. Insects 2011-12-08 2 4 Review 10.3390/insects2040532 532 539 2075-4450 2011-12-08 doi: 10.3390/insects2040532 Yoshio Katsuda Yoshihiro Minamite Charunee Vongkaluang http://www.mdpi.com/2075-4450/2/4/515 Bacteria excel in most ecological niches, including insect symbioses. A cluster of bacterial symbionts, established within a broad range of insects, share high 16S rRNA similarities with the secondary symbiont of the tsetse fly (Diptera: Glossinidae), Sodalis glossinidius. Although 16S rRNA has proven informative towards characterization of this clade, the gene is insufficient for examining recent divergence due to selective constraints. Here, we assess the application of the internal transcribed spacer (ITS) regions, specifically the ITSglu and ITSala,ile, used in conjunction with 16S rRNA to enhance the phylogenetic resolution of Sodalis-allied bacteria. The 16S rRNA + ITS regions of Sodalis and allied bacteria demonstrated significant divergence and were robust towards phylogenetic resolution. A monophyletic clade of Sodalis isolates from tsetse species, distinct from other Enterobacteriaceae, was consistently observed suggesting diversification due to host adaptation. In contrast, the phylogenetic distribution of symbionts isolated from hippoboscid flies and various Hemiptera and Coleoptera were intertwined suggesting either horizontal transfer or a recent establishment from an environmental source. Lineage splitting of Sodalis-allied bacteria into symbiotic and free-living sister groups was also observed. Additionally, we propose an ITS region as a diagnostic marker for the identification of additional Sodalis-allied symbionts in the field. These results expand our knowledge of informative genome regions to assess genetic divergence since splitting from the last common ancestor, of this versatile insect symbiont clade that have become increasingly recognized as valuable towards our understanding of the evolution of symbiosis. These facultative and recently associated symbionts may provide a novel source of traits adaptable to the dynamic ecologies encountered by diverse host backgrounds. Insects 2011-11-30 2 4 Article 10.3390/insects2040515 515 531 2075-4450 2011-11-30 doi: 10.3390/insects2040515 Anna K. Snyder Kenneth Z. Adkins Rita V. M. Rio http://www.mdpi.com/2075-4450/2/4/509 Endoparasitoid wasps inject a variety of components into their host hemocoel at oviposition to facilitate successful development of their progeny. Among these are venom proteins which have been shown to play crucial roles in host regulation. A serine protease homolog (SPH)-like venom protein from Cotesia rubecula was previously shown to inhibit melanization in the host hemolymph by blocking activation of prophenoloxidase to phenoloxidase, a key enzyme in melanin formation. Similar to other SPHs, Vn50 consists of a clip and a protease-like (SPL) domain. Protein modeling demonstrated that Vn50 has a very similar structure to known SPHs and functional analysis of Vn50 domains expressed in insect cells indicated that neither of the domains on its own has an inhibitory effect on melanization. Insects 2011-11-25 2 4 Communication 10.3390/insects2040509 509 514 2075-4450 2011-11-25 doi: 10.3390/insects2040509 Pune Thomas Sassan Asgari http://www.mdpi.com/2075-4450/2/4/499 The Formosan subterranean termite, Coptotermes formosanus Shiraki, and the Asian subterranean termite, Coptotermes gestroi (Wasmann), are both pests of wood in service in Hawaii and Florida. We conducted a laboratory study using method modified from those described in standard E1-09 of the American Wood Protection Association (AWPA 2009) to assess the termite resistance of three commercially available wood species used in regions of the USA where both termite species occur: Douglas fir, Pseudotsuga menziessii, southern yellow pine, Pinus spp. and redwood, Sequoia sempervirens. A multiple-choice (three-choice) assay was used for four weeks (28 days) in order to simulate field conditions of food choice and assess termite feeding preferences under 28 °C and 72–80% RH. 400 termites (360 workers: 40 soldiers) were released into each test jar. Five replicates and two controls of each wood species were used with each termite species. Termite mortality was recorded at the end of the test; and wood wafers were oven-dried and weighed before and after termite exposure to determine the mass loss due to termite feeding, and rated visually on a 0 (failure) to 10 (sound) scale. There were significant differences in mean mass loss values among the three wood species and between two termite species. The mean mass loss value for redwood was significantly lower than Douglas fir and southern yellow pine with both termite species. However, C. formosanus showed increased feeding on Douglas fir and southern yellow pine compared to C. gestroi. Insects 2011-11-25 2 4 Article 10.3390/insects2040499 499 508 2075-4450 2011-11-25 doi: 10.3390/insects2040499 Nirmala K. Hapukotuwa J. Kenneth Grace http://www.mdpi.com/2075-4450/2/4/491 The utilization of pesticides often leaves residues which potentially pollute the environment. This journal issue has been encouraging some researchers to find an environmentally friendly insecticide by a cheaper wood preservative method. The International Standard for Phytosanitary Measures 15 (ISPM 15) [1] that is adopted in wood packaging protection in Europe is not suitable for tropical countries like Indonesia. Therefore, the treatment by Organo-Complex-based wood preservation, which consists of copper chromium combined with natural organic compounds, is proposed for effective treatment at a lower cost. The bioassay test was subjected to dry wood termite Cryptotermes cynocephalus Light. The result showed that wood materials treated by 10 ppm Organo-Complex formula gave good results which were indicated by the low consumption and the fast termination of the termites. The toxicity analysis of C-C organic compound solution is classified as grade IV (WHO, 2003) [2], or not harmful. Analysis of the residual content four weeks after the spraying treatment showed a significant reduction in the inorganic content (copper chromate complex), in the range of 35%, and in extracts of natural materials (natural extracts), above 80%. Insects 2011-11-15 2 4 Article 10.3390/insects2040491 491 498 2075-4450 2011-11-15 doi: 10.3390/insects2040491 Maya Ismayati Khoirul Himmi Setiawan Didi Tarmadi Deni Zulfiana Sulaeman Yusuf Budi Santoso http://www.mdpi.com/2075-4450/2/4/486 The effectiveness of a chlorfluazuron termite bait in eliminating colonies of the termite species Macrotermes gilvus (Hagen) was evaluated under field conditions. Three active termite mounds were chosen for this study, two acted as test mounds and the other as the control. Four In-Ground Stations (IGS) were installed around each mound. Interception occurred almost immediately in all the stations, which were subsequently baited. The control mound was fed a bait matrix lacking the active ingredient. Stations were re-baited every 2 weeks for 10–12 weeks until bait consumption ceased in the test mounds. The mounds were left undisturbed for four more weeks before being destructively sampled. The desiccated remains of workers, soldiers, late instars and queen were found upon sampling the treated mounds. A few live termites were located in one treated mound but were darkly pigmented indicating bait consumption. The control mound remained healthy and did not show any visible sign of negative impact. The bait successfully suppressed or eliminated both M. gilvus colonies within 16 weeks from commencement of feeding. Insects 2011-11-10 2 4 Product Review 10.3390/insects2040486 486 490 2075-4450 2011-11-10 doi: 10.3390/insects2040486 Partho Dhang