Insects

14 pages, 2377 KiB

Open AccessEditor’s ChoiceArticle

Increased Phenoloxidase Activity Constitutes the Main Defense Strategy of Trichoplusia ni Larvae against Fungal Entomopathogenic Infections

by Kristin R. Duffield, Alayna M. Rosales, Ephantus J. Muturi, Robert W. Behle and José L. Ramirez

Insects 2023, 14(8), 667; https://doi.org/10.3390/insects14080667 - 25 Jul 2023

Cited by 8 | Viewed by 2372

Abstract

The cabbage looper Trichoplusia ni is an important agricultural pest worldwide and is frequently used as a model organism for assessing entomopathogenic fungi virulence, though few studies have measured the host response repertoire to fungal biocontrol agents. Here, we quantified the immune response [...] Read more.

The cabbage looper Trichoplusia ni is an important agricultural pest worldwide and is frequently used as a model organism for assessing entomopathogenic fungi virulence, though few studies have measured the host response repertoire to fungal biocontrol agents. Here, we quantified the immune response of T. ni larvae following exposure to two entomopathogenic fungal species: Beauveria bassiana and Cordyceps javanica. Results from our study demonstrate that T. ni larvae exposed to fungal entomopathogens had higher total phenoloxidase activity compared to controls, indicating that the melanization cascade is one of the main immune components driving defense against fungal infection and contrasting observations from other insect–fungi interaction studies. We also observed differences in host response depending on the species of entomopathogenic fungi, with significantly higher induction observed during infections with B. bassiana than with C. javanica. Larvae exposed to B. bassiana had an increased expression of genes involved in prophenoloxidase response and the Imd, JNK, and Jak/STAT immune signaling pathways. Our results indicate a notable absence of Toll pathway-related responses, further contrasting results to other insect–fungi pathosystems. Important differences were also observed in the induction of antimicrobial effectors, with B. bassiana infections eliciting three antimicrobial effectors (lysozyme, gloverin, and cecropin), while C. javanica only induced cecropin expression. These results provide insight into the host response strategies employed by T. ni for protection against entomopathogenic fungi and increase our understanding of insect–fungal entomopathogen interactions, aiding in the design of more effective microbial control strategies for this important agricultural pest. Full article

(This article belongs to the Section Insect Behavior and Pathology)

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25 pages, 444 KiB

Open AccessEditor’s ChoiceReview

Overview of Updated Control Tactics for Western Flower Thrips

by Daniel Rodríguez and Ericsson Coy-Barrera

Insects 2023, 14(7), 649; https://doi.org/10.3390/insects14070649 - 20 Jul 2023

Cited by 18 | Viewed by 5558

Abstract

Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), broadly known as Western flower thrips (WFT), are currently one of the most critical pests worldwide in field and greenhouse crops, and their management is full of yet unsolved challenges derived from their high reproductive potential, cryptic habit, [...] Read more.

Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), broadly known as Western flower thrips (WFT), are currently one of the most critical pests worldwide in field and greenhouse crops, and their management is full of yet unsolved challenges derived from their high reproductive potential, cryptic habit, and ability to disperse. The control of this pest relies widely on chemical control, despite the propensity of the species to develop resistance. However, significant advances have been produced through biological and ethological control. Although there has recently been a remarkable amount of new information regarding the management of this pest worldwide, there is no critical analysis of recent developments and advances in the attractive control tactics for WFT, constituting the present compilation’s aim. Hence, this narrative review provides an overview of effective control strategies for managing thrips populations. By understanding the pest’s biology, implementing monitoring techniques, accurately identifying the species, and employing appropriate control measures, farmers and researchers can mitigate the WFT impact on agricultural production and promote sustainable pest management practices. Full article

(This article belongs to the Special Issue Invasive Arthropod Pests - Volume II)

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22 pages, 6007 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Genome and Transcriptome Analyses Facilitate Genetic Control of Wohlfahrtia magnifica, a Myiasis-Causing Flesh Fly

by Zhipeng Jia, Surong Hasi, Deng Zhan, Bin Hou, Claus Vogl and Pamela A. Burger

Insects 2023, 14(7), 620; https://doi.org/10.3390/insects14070620 - 10 Jul 2023

Cited by 1 | Viewed by 2567

Abstract

Myiasis caused by Wohlfahrtia magnifica is a widespread parasitic infestation in mammals. The infested host suffers from damage as the developing larvae feed on its tissues. For the control of myiasis infestation, genetic methods have been shown to be effective and promising as [...] Read more.

Myiasis caused by Wohlfahrtia magnifica is a widespread parasitic infestation in mammals. The infested host suffers from damage as the developing larvae feed on its tissues. For the control of myiasis infestation, genetic methods have been shown to be effective and promising as an alternative to insecticides. Combining genome, isoform sequencing (Iso-Seq), and RNA sequencing (RNA-seq) data, we isolated and characterized two sex-determination genes, W. magnifica transformer (Wmtra) and W. magnifica transformer2 (Wmtra2), whose orthologs in a number of insect pests have been utilized to develop genetic control approaches. Wmtra transcripts are sex-specifically spliced; only the female transcript encodes a full-length functional protein, while the male transcript encodes a truncated and non-functional polypeptide due to the presence of the male-specific exon containing multiple in-frame stop codons. The existence of five predicted TRA/TRA2 binding sites in the male-specific exon and the surrounding intron of Wmtra, as well as the presence of an RNA-recognition motif in WmTRA2 may suggest the auto-regulation of Wmtra by its own protein interacting with WmTRA2. This results in the skipping of the male-specific exon and translation of the full-length functional protein only in females. Our comparative study in dipteran species showed that both the WmTRA and WmTRA2 proteins exhibit a high degree of similarity to their orthologs in the myiasis-causing blow flies. Additionally, transcriptome profiling performed between adult females and adult males reported 657 upregulated and 365 downregulated genes. Functional analysis showed that among upregulated genes those related to meiosis and mitosis Gene Ontology (GO) terms were enriched, while, among downregulated genes, those related to muscle cell development and aerobic metabolic processes were enriched. Among the female-biased gene set, we detected five candidate genes, vasa (vas), nanos (nanos), bicoid (bcd), Bicaudal C (BicC), and innexin5 (inx5). The promoters of these genes may be able to upregulate Cas9 expression in the germline in Cas9-based homing gene drive systems as established in some flies and mosquitoes. The isolation and characterization of these genes is an important step toward the development of genetic control programs against W. magnifica infestation. Full article

(This article belongs to the Section Insect Molecular Biology and Genomics)

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12 pages, 1837 KiB

Open AccessEditor’s ChoiceArticle

The Effect of X-ray Irradiation on the Fitness and Field Adaptability of the Codling Moth: An Orchard Study in Northeast China

by Jinghan Zhang, Shengwang Huang, Shici Zhao, Xingya Wang, Xianming Yang, Huiyuan Zhao, Ping Gao, Yuting Li and Xueqing Yang

Insects 2023, 14(7), 615; https://doi.org/10.3390/insects14070615 - 7 Jul 2023

Cited by 7 | Viewed by 1944

Abstract

The codling moth, Cydia pomonella (L.), is an invasive agricultural pest of pome fruits and walnuts in China that threatens the apple industry in the Loess Plateau and Bohai Bay; it has developed resistance to many insecticides. Sterile insect technique (SIT) combined with [...] Read more.

The codling moth, Cydia pomonella (L.), is an invasive agricultural pest of pome fruits and walnuts in China that threatens the apple industry in the Loess Plateau and Bohai Bay; it has developed resistance to many insecticides. Sterile insect technique (SIT) combined with area-wide integrated pest management (AW-IPM) can reduce the risk of resistance to insecticides and effectively control some insect pest species. Our previous laboratory experiment found that irradiation with 366 Gy of X-ray caused the males of the codling moth to become sterile. However, the sterility and adaptability of males after being irradiated with 366 Gy X-ray in the field are still unclear. In this study, we investigated the effect of X-ray irradiation on the fitness of male adults that emerged from pupae irradiated with 366 Gy to explore their adaptability and mating competitiveness, and to examine the effect of releasing sterile male insects in orchards in northeast China on the fruit infestation rate of the Nanguo pear. The results showed that 366 Gy of X-ray irradiation significantly reduced the mating competitiveness of males and the hatching rate of the eggs laid by females pairing with sterile males. Meanwhile, the lifespan of the sterile male moths was significantly shorter than that of the normal ones in the field. A pilot test showed that the release twice of sterile male moths in the orchards had no significant effect on the fruit infestation rate. Our field experiments provide a scientific basis for the further optimization of the SIT technology program for controlling C. pomonella. Full article

(This article belongs to the Special Issue Environmentally-Friendly Pest Control Approaches for Invasive Insects)

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16 pages, 15593 KiB

Open AccessEditor’s ChoiceArticle

Tribe Acalyptaini (Hemiptera: Tingidae: Tinginae) Revisited: Can Apomorphies in Secondary and Tertiary Structures of 18S rRNA Length-Variable Regions (LVRs) Support Tribe Validity?

by Barbara Lis, Paweł J. Domagała and Jerzy A. Lis

Insects 2023, 14(7), 600; https://doi.org/10.3390/insects14070600 - 3 Jul 2023

Cited by 1 | Viewed by 1819

Abstract

The lace bug tribe Acalyptaini (Tingidae: Tinginae) includes five genera, Acalypta, Derephysia, Dictyonota, Kalama, and Recaredus, and it was recently resurrected based on morphological and karyological characters. We aimed to validate the distinctiveness of this tribe using 18S rDNA sequences, [...] Read more.

The lace bug tribe Acalyptaini (Tingidae: Tinginae) includes five genera, Acalypta, Derephysia, Dictyonota, Kalama, and Recaredus, and it was recently resurrected based on morphological and karyological characters. We aimed to validate the distinctiveness of this tribe using 18S rDNA sequences, which have not been used in previous Tingidae phylogenomic studies. Our results confirmed the monophyly of the tribe. Moreover, the monophyly of the subfamily Cantacaderinae and its basal position within the family Tingidae were indicated, as well as the position of the tribe Litadeini as sister to all other Tinginae. In addition, we attempted to determine the apomorphic morpho-molecular characters in the secondary and tertiary structures of length-variable regions of the 18S rRNA sequences of the analysed species. The results showed that two LVRs (LVR X and LVR L) of the hypervariable region V4 exhibited significant variability in the number of nucleotides and could be considered for apomorphic recognition. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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27 pages, 3520 KiB

Open AccessEditor’s ChoiceReview

Establishing an Integrated Pest Management Program for Coffee Berry Borer (Hypothenemus hampei) in Hawaii and Puerto Rico Coffee Agroecosystems: Achievements and Challenges

by Luis F. Aristizábal, Melissa A. Johnson, Yobana A. Mariño, Paul Bayman and Mark G. Wright

Insects 2023, 14(7), 603; https://doi.org/10.3390/insects14070603 - 3 Jul 2023

Cited by 12 | Viewed by 4657

Abstract

Coffee berry borer (CBB) is the most serious insect pest of coffee worldwide, causing significant reductions in yield and quality. Following the introduction of CBB to Puerto Rico (2007) and Hawaii (2010), researchers, extension agents, industry representatives, and coffee growers have worked together [...] Read more.

Coffee berry borer (CBB) is the most serious insect pest of coffee worldwide, causing significant reductions in yield and quality. Following the introduction of CBB to Puerto Rico (2007) and Hawaii (2010), researchers, extension agents, industry representatives, and coffee growers have worked together to develop an integrated pest management (IPM) program that is both effective and economically feasible for each island. Since the introduction of the IPM program in Hawaii, research efforts have led to a better understanding of CBB population dynamics, as well as optimized monitoring, cultural practices, and commercial Beauveria bassiana applications. As a result of these efforts, a substantial reduction in average CBB infestation and an increase in coffee yields and quality have been documented in Hawaii over the last decade. However, significant challenges remain in addressing high production and labor costs, limited availability of labor, and a lack of training for field workers in both regions. Although considerable effort has gone into research to support CBB IPM in Hawaii and Puerto Rico, the adoption of these strategies by coffee farmers needs to be increased. More diversified methods of outreach and education are needed to reach growers in rural, isolated areas. Significant gaps exist in the ability and willingness of growers and workers to access and digest information online, emphasizing the importance of on-farm workshops and farmer-to-farmer teaching. Additional methods of training are needed to help coffee farmers and field workers learn how to properly conduct cultural controls and optimize the use of biological control agents such as B. bassiana. Full article

(This article belongs to the Special Issue Biology, Ecology, and Management of the Coffee Berry Borer (Hypothenemus hampei))

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15 pages, 1115 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Colonization Resistance of Symbionts in Their Insect Hosts

by Zhengyan Wang, Hanzi Yong, Shan Zhang, Zhiyuan Liu and Yaru Zhao

Insects 2023, 14(7), 594; https://doi.org/10.3390/insects14070594 - 30 Jun 2023

Cited by 15 | Viewed by 3231

Abstract

The symbiotic microbiome is critical in promoting insect resistance against colonization by exogenous microorganisms. The mechanisms by which symbionts contribute to the host’s immune capacity is referred to as colonization resistance. Symbionts can protect insects from exogenous pathogens through a variety of mechanisms, [...] Read more.

The symbiotic microbiome is critical in promoting insect resistance against colonization by exogenous microorganisms. The mechanisms by which symbionts contribute to the host’s immune capacity is referred to as colonization resistance. Symbionts can protect insects from exogenous pathogens through a variety of mechanisms, including upregulating the expression of host immune-related genes, producing antimicrobial substances, and competitively excluding pathogens. Concordantly, insects have evolved fine-tuned regulatory mechanisms to avoid overactive immune responses against symbionts or specialized cells to harbor symbionts. Alternatively, some symbionts have evolved special adaptations, such as the formation of biofilms to increase their tolerance to host immune responses. Here, we provide a review of the mechanisms about colonization resistance of symbionts in their insect hosts. Adaptations of symbionts and their insect hosts that may maintain such symbiotic relationships, and the significance of such relationships in the coevolution of symbiotic systems are also discussed to provide insights into the in-depth study of the contribution of symbionts to host physiology and behavior. Full article

(This article belongs to the Collection Insect Immunity: Evolution, Genomics and Physiology)

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14 pages, 2340 KiB

Open AccessEditor’s ChoiceArticle

Miticidal Tools for Management of Southern Red Mites Infesting Southern Highbush Blueberries

by Lorena Lopez and Oscar E. Liburd

Insects 2023, 14(7), 573; https://doi.org/10.3390/insects14070573 - 21 Jun 2023

Viewed by 2952

Abstract

Tetranychid outbreaks have been detected since 2016 in southern highbush blueberries (SHB); however, it was not until 2019 that the southern red mite (SRM), Oligonychus ilicis (Acari: Tetranychidae) was confirmed as the pest causing severe bronzing and stunting, in multiple Florida and Georgia [...] Read more.

Tetranychid outbreaks have been detected since 2016 in southern highbush blueberries (SHB); however, it was not until 2019 that the southern red mite (SRM), Oligonychus ilicis (Acari: Tetranychidae) was confirmed as the pest causing severe bronzing and stunting, in multiple Florida and Georgia commercial blueberry plantings. To date, only three miticides (fenazaquin, fenpyroximate, and acequinocyl) have been registered for use in SHB and there are no clear guidelines on how to manage SRM in SHB. Similarly, there is no knowledge regarding the existence of natural enemies of SRM in SHB. This is the first report of naturally occurring predatory mites (Amblyseius sp. and Neoseiulus ilicis) associated with SRM in SHB. Predatory mites were recorded in blueberry bushes after treatment with seven miticides used to suppress SRM populations including spiromesifen, acequinocyl, sulfur, sulfur + molasses, bifenazate, fenpyroximate, and fenazaquin. The number of SRM recorded per leaf and averaged plant damage ratings (0 = no bronzing–4 = 100% bronzing) were used to evaluate miticide efficacy. Additionally, the presence or absence of predatory mites per sample was recorded. Fenpyroximate used as the standard miticide, significantly reduced mite numbers seven days after application, as well as acequinocyl and fenazaquin. Fenpyroximate and fenazaquin demonstrated the best performance for managing O. ilicis on SHB and treated bushes demonstrated significantly less bronzing compared with the control plants. These miticides were also safe to naturally occurring predatory mites. Lastly, the level of growers’ awareness regarding SRM was assessed using surveys in 2020 to design adequate educational materials available to the grower community. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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12 pages, 1153 KiB

Open AccessEditor’s ChoiceArticle

Spent Coffee Grounds and Novaluron Are Toxic to Aedes aegypti (Diptera: Culicidae) Larvae

by Waralee Thanasoponkul, Tanasak Changbunjong, Rattanavadee Sukkurd and Tawee Saiwichai

Insects 2023, 14(6), 564; https://doi.org/10.3390/insects14060564 - 16 Jun 2023

Cited by 4 | Viewed by 5300

Abstract

Aedes aegypti (Diptera: Culicidae) is a vector for mosquito-borne diseases worldwide. Insecticide resistance is a major concern in controlling this mosquito. We investigated the chemical compounds in wet and dry spent coffee grounds (wSCGs and dSCGs) and evaluated the efficacy of dSCGs, wSCGs, [...] Read more.

Aedes aegypti (Diptera: Culicidae) is a vector for mosquito-borne diseases worldwide. Insecticide resistance is a major concern in controlling this mosquito. We investigated the chemical compounds in wet and dry spent coffee grounds (wSCGs and dSCGs) and evaluated the efficacy of dSCGs, wSCGs, and novaluron on the mortality and adult emergence inhibition of Ae. aegypti. We found higher concentrations of chemical compounds in wSCGs than in dSCGs. The wSCGs and dSCGs both contained total phenolic compounds, total flavonoid compounds, caffeic acid, coumaric acid, protocatechuic acid, and vanillic acid. Complete mortality was observed after 48 h of exposure to 50 g/L wSCGs, while similar mortality was found after 120 h of exposure to 10 µg/L of novaluron. The sublethal dose was a concentration of wSCGs (5 g/L) and novaluron (0.01, 0.1, and 1 µg/L) combined that resulted in a larval mortality lower than twenty percent (at 72 h) to determine their synergistic effects. The death rate of larvae exposed in sublethal combination of wSCGs and novaluron was significantly higher than that of its stand-alone. The findings indicate that the combination of wSCGs and novaluron at sublethal concentrations had synergistic effects on the mortality of Ae. aegypti larvae and could be applied as an alternative control measure. Full article

(This article belongs to the Special Issue The Efficacy of Insecticides and Botanicals against Pests)

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18 pages, 4325 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Northern Richness, Southern Dead End—Origin and Dispersal Events of Pseudolycoriella (Sciaridae, Diptera) between New Zealand’s Main Islands

by Arne Köhler and Thomas Schmitt

Insects 2023, 14(6), 548; https://doi.org/10.3390/insects14060548 - 12 Jun 2023

Cited by 1 | Viewed by 1870

Abstract

Sciaridae (Diptera) is a widespread insect family of which some species can reach high abundances in arboreal habitats. This trait, together with their (passive) mobility, enables them to quickly colonise suitable habitats. To reveal the biogeographic history of the New Zealand members of [...] Read more.

Sciaridae (Diptera) is a widespread insect family of which some species can reach high abundances in arboreal habitats. This trait, together with their (passive) mobility, enables them to quickly colonise suitable habitats. To reveal the biogeographic history of the New Zealand members of the sciarid genus Pseudolycoriella, we analysed three molecular markers of selected species and populations in a Bayesian approach. At the intra- and interspecific levels, we detected a pattern of northern richness vs. southern purity, which has probably developed as a result of Pleistocene glacial cycles. Since the late Miocene, we identified 13 dispersal events across the sea strait separating New Zealand’s main islands. As nine of these dispersal events were south-directed, North Island can be considered the centre of radiation for this genus. An unequivocal re-colonisation of North Island was only observed once. Based on the inclusion of three undescribed species from Tasmania and on previously published data, three colonisations of New Zealand are likely, all of them assumed to be of Australian origin. One of these most probably took place during the late Miocene, and the other two during the late Pliocene or at the Pliocene–Pleistocene boundary. Full article

(This article belongs to the Special Issue Systematics, Taxonomy and Biodiversity of Sciaridae (Diptera))

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20 pages, 3370 KiB

Open AccessEditor’s ChoiceArticle

Lethal and Sublethal Effects of Contact Insecticides and Horticultural Oils on the Hibiscus Bud Weevil, Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae)

by A. Daniel Greene, Xiangbing Yang, Yisell Velazquez-Hernandez, German Vargas, Paul E. Kendra, Catharine Mannion and Alexandra M. Revynthi

Insects 2023, 14(6), 544; https://doi.org/10.3390/insects14060544 - 11 Jun 2023

Cited by 6 | Viewed by 2580

Abstract

In 2017, the hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae), was found outside of its native range of Mexico and Texas, infesting hibiscus plants in Florida. Therefore, we selected 21 different insecticide and horticultural oil products to evaluate their effects on [...] Read more.

In 2017, the hibiscus bud weevil (HBW), Anthonomus testaceosquamosus Linell (Coleoptera: Curculionidae), was found outside of its native range of Mexico and Texas, infesting hibiscus plants in Florida. Therefore, we selected 21 different insecticide and horticultural oil products to evaluate their effects on the reproductive rate, feeding, and oviposition behavior of the HBW. In laboratory experiments, significant mortality was observed in adult weevils exposed to diflubenzuron-treated hibiscus leaves and buds, and hibiscus buds treated with diflubenzuron contained the fewest number of eggs and feeding/oviposition holes. Among horticultural oil products, significant mortality was only observed in experiments in which adult weevils were directly sprayed (direct experiments). Pyrethrins and spinetoram plus sulfoxaflor reduced the oviposition rate and caused significant mortality in direct experiments. Diflubenzuron, pyrethrins, spinetoram plus sulfoxaflor, and spirotetramat were further tested via contact toxicity experiments and greenhouse experiments. Contact toxicity experiments demonstrated that the tested insecticides (except diflubenzuron) were highly toxic to HBW adults. In greenhouse experiments, only those hibiscus plants treated with pyrethrins had significantly fewer feeding/oviposition holes and larvae within their flower buds when compared to control (water-treated) plants. These results constitute an important first step in the identification of effective chemical control options for the HBW. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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14 pages, 2700 KiB

Open AccessEditor’s ChoiceArticle

Granger Causality Analysis of Transient Calcium Dynamics in the Honey Bee Antennal Lobe Network

by Marco Paoli, Yuri Antonacci, Angela Albi, Luca Faes and Albrecht Haase

Insects 2023, 14(6), 539; https://doi.org/10.3390/insects14060539 - 9 Jun 2023

Cited by 2 | Viewed by 1773

Abstract

Odorant processing presents multiple parallels across animal species, and insects became relevant models for the study of olfactory coding because of the tractability of the underlying neural circuits. Within the insect brain, odorants are received by olfactory sensory neurons and processed by the [...] Read more.

Odorant processing presents multiple parallels across animal species, and insects became relevant models for the study of olfactory coding because of the tractability of the underlying neural circuits. Within the insect brain, odorants are received by olfactory sensory neurons and processed by the antennal lobe network. Such a network comprises multiple nodes, named glomeruli, that receive sensory information and are interconnected by local interneurons participating in shaping the neural representation of an odorant. The study of functional connectivity between the nodes of a sensory network in vivo is a challenging task that requires simultaneous recording from multiple nodes at high temporal resolutions. Here, we followed the calcium dynamics of antennal lobe glomeruli and applied Granger causality analysis to assess the functional connectivity among network nodes in the presence and absence of an odorous stimulus. This approach revealed the existence of causal connectivity links between antennal lobe glomeruli in the absence of olfactory stimulation, while at odor arrival, the connectivity network’s density increased and became stimulus-specific. Thus, such an analytical approach may provide a new tool for the investigation of neural network plasticity in vivo. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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15 pages, 1198 KiB

Open AccessEditor’s ChoiceArticle

Movement of Striacosta albicosta (Smith) (Lepidoptera: Noctuidae) Larvae on Transgenic Bt and Non-Bt Maize

by Débora G. Montezano, Thomas E. Hunt, Priscila M. Colombo da Luz, Kelsey Karnik, Stephen D. Kachman, Ana M. Vélez and Julie A. Peterson

Insects 2023, 14(6), 524; https://doi.org/10.3390/insects14060524 - 5 Jun 2023

Cited by 1 | Viewed by 2076

Abstract

Exposure of lepidopteran pests to Bacillus thuringiensis (Bt) proteins has been shown to affect the behavior of larvae, including increased movement and avoidance of Bt-expressing plants or diet. Therefore, we hypothesized that the behavior of western bean cutworm, Striacosta albicosta [...] Read more.

Exposure of lepidopteran pests to Bacillus thuringiensis (Bt) proteins has been shown to affect the behavior of larvae, including increased movement and avoidance of Bt-expressing plants or diet. Therefore, we hypothesized that the behavior of western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), an important pest of maize, could be affected when exposed to Bt plants. To test this hypothesis, we conducted a series of artificial arena and on-plant experiments to determine S. albicosta neonate behavior when exposed to Bt and non-Bt plant tissue. Video tracking experiments presented neonate larvae with the choice of Bt or non-Bt pollen in a Petri dish for 15 min while being video recorded for analysis with EthoVision software. This study showed an increase in mean velocity and total time spent moving for larvae in the presence of Cry1F vs. non-Bt when compared with Vip3A vs. non-Bt or Cry1F vs. Vip3A. However, there was no difference in total distance moved or time spent in the food zone for all scenarios. Maize tissue choice experiments allowed neonatal larvae the choice of feeding on Bt or non-Bt tassel or leaves for 9 h in Petri dish arenas. This experiment showed that larvae preferred tassel tissue over leaves but did not indicate that larvae could distinguish between Bt and non-Bt tissue. In contrast, on-plant experiments (including a whole plant neonate dispersal study under controlled conditions and an in-field silking behavior experiment) indicated that the presence of Cry1F and Vip3A Bt toxins increased plant abandonment, suggesting that larvae are able to detect and avoid Bt toxins. The discrepancy of these results is likely due to the on-plant studies providing more field-realistic environmental conditions and a longer duration of exposure to Bt toxins for the behavioral experiments. Our results represent the first steps in understanding the complex behavior of S. albicosta when exposed to Bt plants. A better understanding of the response of larvae when exposed to Bt traits can aid in the management of this pest, particularly for the design of resistance management strategies and refuge design. Full article

(This article belongs to the Special Issue Resistance of Pests to Insecticidal Proteins from Bacillus thuringiensis (Bt))

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30 pages, 7417 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Collembola of the Cavalum and Landeiro Caves (Madeira, Portugal)

by Enrique Baquero, Javier I. Arbea, Élvio Nunes, Dora Aguin-Pombo, Eduardo Mateos and Rafael Jordana

Insects 2023, 14(6), 525; https://doi.org/10.3390/insects14060525 - 5 Jun 2023

Cited by 1 | Viewed by 1855

Abstract

The cave fauna of the Macaronesian archipelagos is rich in endemic species. Unlike the Azores and the Canary Islands, the cave fauna of the Madeira archipelago is little known. The only two cave complexes studied, Machico and São Vicente, lack protection measures. São [...] Read more.

The cave fauna of the Macaronesian archipelagos is rich in endemic species. Unlike the Azores and the Canary Islands, the cave fauna of the Madeira archipelago is little known. The only two cave complexes studied, Machico and São Vicente, lack protection measures. São Vicente is seriously threatened because it is being exploited for touristic purposes, while the Machico complex, the only one in its natural state, is open to the public but without any control. The importance of the conservation of this cave fauna is indisputable. So far, of the 13 cavernicolous species recorded, two of them—genus Centromerus—are critically endangered. Apart from occasional sampling, no monitoring study has ever been carried out. The aim of this work has been to make a species checklist of the cave fauna of the Machico complex, the least studied so far. For this purpose, during 2001–2002, a monitoring study was carried out using traps and manual collections in the lava tubes of Landeiros and Cavalum (I, II, III). Fourteen species of springtails were recorded. Of these, four are new species, Neelus serratus Jordana & Baquero sp. nov., Coecobrya decemsetosa Jordana & Baquero sp. nov., Coecobrya octoseta Jordana & Baquero sp. nov., and Sinella duodecimoculata Jordana & Baquero sp. nov., and one is a new record for the archipelago, Lepidocyrtus curvicollis Bourlet, 1839. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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23 pages, 8178 KiB

Open AccessEditor’s ChoiceArticle

Engineered Human Tissue as A New Platform for Mosquito Bite-Site Biology Investigations

by Corey E. Seavey, Mona Doshi, Andrew P. Panarello, Michael A. Felice, Andrew K. Dickerson, Mollie W. Jewett and Bradley J. Willenberg

Insects 2023, 14(6), 514; https://doi.org/10.3390/insects14060514 - 2 Jun 2023

Cited by 2 | Viewed by 7966

Abstract

Vector-borne diseases transmitted through the bites of hematophagous arthropods, such as mosquitoes, continue to be a significant threat to human health globally. Transmission of disease by biting arthropod vectors includes interactions between (1) saliva expectorated by a vector during blood meal acquisition from [...] Read more.

Vector-borne diseases transmitted through the bites of hematophagous arthropods, such as mosquitoes, continue to be a significant threat to human health globally. Transmission of disease by biting arthropod vectors includes interactions between (1) saliva expectorated by a vector during blood meal acquisition from a human host, (2) the transmitted vector-borne pathogens, and (3) host cells present at the skin bite site. Currently, the investigation of bite-site biology is challenged by the lack of model 3D human skin tissues for in vitro analyses. To help fill this gap, we have used a tissue engineering approach to develop new stylized human dermal microvascular bed tissue approximates—complete with warm blood—built with 3D capillary alginate gel (Capgel) biomaterial scaffolds. These engineered tissues, termed a Biologic Interfacial Tissue-Engineered System (BITES), were cellularized with either human dermal fibroblasts (HDFs) or human umbilical vein endothelial cells (HUVECs). Both cell types formed tubular microvessel-like tissue structures of oriented cells (82% and 54% for HDFs and HUVECs, respectively) lining the unique Capgel parallel capillary microstructures. Female Aedes (Ae.) aegypti mosquitoes, a prototypic hematophagous biting vector arthropod, swarmed, bit, and probed blood-loaded HDF BITES microvessel bed tissues that were warmed (34–37 °C), acquiring blood meals in 151 ± 46 s on average, with some ingesting ≳4 µL or more of blood. Further, these tissue-engineered constructs could be cultured for at least three (3) days following blood meal acquisitions. Altogether, these studies serve as a powerful proof-of-concept demonstration of the innovative BITES platform and indicate its potential for the future investigation of arthropod bite-site cellular and molecular biology. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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18 pages, 1979 KiB

Open AccessEditor’s ChoiceArticle

Mosquito Larvicidal Activity and Cytotoxicity of the Extracts of Aromatic Plants from Malaysia

by Huimei Lim, Sook Yee Lee, Lai Yee Ho and Nam Weng Sit

Insects 2023, 14(6), 512; https://doi.org/10.3390/insects14060512 - 1 Jun 2023

Cited by 20 | Viewed by 10278

Abstract

Despite ongoing control efforts, the mosquito population and diseases vectored by them continue to thrive worldwide, causing major health concerns. There has been growing interest in the use of botanicals as alternatives to insecticides due to their widespread insecticidal properties, biodegradability, and adaptability [...] Read more.

Despite ongoing control efforts, the mosquito population and diseases vectored by them continue to thrive worldwide, causing major health concerns. There has been growing interest in the use of botanicals as alternatives to insecticides due to their widespread insecticidal properties, biodegradability, and adaptability to ecological conditions. In this study, we investigated the larvicidal activity and cytotoxicity effects of solvent extracts from three aromatic plants—Curcuma longa (turmeric), Ocimum americanum (hoary basil), and Petroselinum crispum (parsley)—against Aedes albopictus. Subsequently, we examined the phytochemical composition of the extracts through gas chromatography–mass spectrometry (GC–MS) analysis. Results revealed that the hexane extracts of O. americanum and P. crispum exhibited the greatest larvicidal activity with the lowest median lethal concentration (LC₅₀) values (<30 µg/mL) at 24 h post-treatment, with the former found to be significantly less toxic towards African monkey kidney (Vero) cells. The GC–MS analysis of the said extract indicated the presence of different classes of metabolites, including phenylpropanoids, very long-chain alkanes, fatty acids and their derivatives, and terpenes, with the most abundant component being methyl eugenol (55.28%), most of which, have been documented for their larvicidal activities. These findings provide valuable insights into the potential use and development of bioinsecticides, particularly from O. americanum. Full article

(This article belongs to the Special Issue The Efficacy of Insecticides and Botanicals against Pests)

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15 pages, 1720 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Abscisic Acid: A Potential Secreted Effector Synthesized by Phytophagous Insects for Host-Plant Manipulation

by Stephannie Seng, Gabriela E. Ponce, Peter Andreas, Anna Kisiala, Rosemarie De Clerck-Floate, Donald G. Miller III, Ming-Shun Chen, Peter W. Price, John F. Tooker, R. J. Neil Emery and Edward F. Connor

Insects 2023, 14(6), 489; https://doi.org/10.3390/insects14060489 - 24 May 2023

Cited by 6 | Viewed by 3338

Abstract

Abscisic acid (ABA) is an isoprenoid-derived plant signaling molecule involved in a wide variety of plant processes, including facets of growth and development as well as responses to abiotic and biotic stress. ABA had previously been reported in a wide variety of animals, [...] Read more.

Abscisic acid (ABA) is an isoprenoid-derived plant signaling molecule involved in a wide variety of plant processes, including facets of growth and development as well as responses to abiotic and biotic stress. ABA had previously been reported in a wide variety of animals, including insects and humans. We used high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-(ESI)-MS/MS) to examine concentrations of ABA in 17 species of phytophagous insects, including gall- and non-gall-inducing species from all insect orders with species known to induce plant galls: Thysanoptera, Hemiptera, Lepidoptera, Coleoptera, Diptera, and Hymenoptera. We found ABA in insect species in all six orders, in both gall-inducing and non-gall-inducing species, with no tendency for gall-inducing insects to have higher concentrations. The concentrations of ABA in insects often markedly exceeded those typically found in plants, suggesting it is highly improbable that insects obtain all their ABA from their host plant via consumption and sequestration. As a follow-up, we used immunohistochemistry to determine that ABA localizes to the salivary glands in the larvae of the gall-inducing Eurosta solidaginis (Diptera: Tephritidae). The high concentrations of ABA, combined with its localization to salivary glands, suggest that insects are synthesizing and secreting ABA to manipulate their host plants. The pervasiveness of ABA among both gall- and non-gall-inducing insects and our current knowledge of the role of ABA in plant processes suggest that insects are using ABA to manipulate source-sink mechanisms of nutrient allocation or to suppress host-plant defenses. ABA joins the triumvirate of phytohormones, along with cytokinins (CKs) and indole-3-acetic acid (IAA), that are abundant, widespread, and localized to glandular organs in insects and used to manipulate host plants. Full article

(This article belongs to the Special Issue Plant Manipulation by Insects: Galls, Green Islands, and More)

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12 pages, 974 KiB

Open AccessEditor’s ChoiceReview

Mechanisms of Neuroendocrine Stress Response in Drosophila and Its Effect on Carbohydrate and Lipid Metabolism

by Margarita A. Bobrovskikh and Nataly E. Gruntenko

Insects 2023, 14(5), 474; https://doi.org/10.3390/insects14050474 - 17 May 2023

Cited by 11 | Viewed by 4312

Abstract

Response to short-term stress is a fundamental survival mechanism ensuring protection and adaptation in adverse environments. Key components of the neuroendocrine stress reaction in insects are stress-related hormones, including biogenic amines (dopamine and octopamine), juvenile hormone, 20-hydroxyecdysone, adipokinetic hormone and insulin-like peptides. In [...] Read more.

Response to short-term stress is a fundamental survival mechanism ensuring protection and adaptation in adverse environments. Key components of the neuroendocrine stress reaction in insects are stress-related hormones, including biogenic amines (dopamine and octopamine), juvenile hormone, 20-hydroxyecdysone, adipokinetic hormone and insulin-like peptides. In this review we focus on different aspects of the mechanism of the neuroendocrine stress reaction in insects on the D. melanogaster model, discuss the interaction of components of the insulin/insulin-like growth factors signaling pathway and other stress-related hormones, and suggest a detailed scheme of their possible interaction and effect on carbohydrate and lipid metabolism under short-term heat stress. The effect of short-term heat stress on metabolic behavior and possible regulation of its mechanisms are also discussed here. Full article

(This article belongs to the Special Issue Insect Hormones, Metabolism, Immunity and Development)

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17 pages, 4660 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Identification and Validation of Reference Genes for Expression Analysis Using RT-qPCR in Leptocybe invasa Fisher and La Salle (Hymenoptera: Eulophidae)

by Ya Liu, Jing Zhou, Zhisong Qiu, Ping Hu, Xiao Chen and Zhende Yang

Insects 2023, 14(5), 456; https://doi.org/10.3390/insects14050456 - 12 May 2023

Cited by 7 | Viewed by 2937

Abstract

Leptocybe invasa (Hymenoptera: Eulophidae) is a globally intrusive pest. Despite extensive research into the physiological responses of this pest, our understanding of the molecular mechanisms still needs to be improved. We want to accurately investigate the expression of L. invasa’s target genes, [...] Read more.

Leptocybe invasa (Hymenoptera: Eulophidae) is a globally intrusive pest. Despite extensive research into the physiological responses of this pest, our understanding of the molecular mechanisms still needs to be improved. We want to accurately investigate the expression of L. invasa’s target genes, so it is imperative to select fitting reference genes. In this study, eight housekeeping genes’ stability (RPS30, ACTR, 18S rRNA, ACT, RPL18, GAPDH, 28S rRNA, and TUB) was tested under five different experimental conditions, including male or female adults, somites (head, thorax, and abdomen), temperatures (0 °C, 25 °C, and 40 °C), diets (starvation, clear water, 10% honey water, Eucalyptus sap), and pesticides (acetone was used as a control, imidacloprid, monosultap). Gene stability was calculated using RefFinder, which integrates four algorithms (the ∆Ct method, geNorm, NormFinder, and BestKeeper). The findings implied that ACT and ACTR were the most accurate when comparing sexes. For analyzing different somites, 28S rRNA and RPL18 were ideal; the 28S rRNA and RRS30 were perfect for analyzing at different temperatures. The combination of ACT and GAPDH helped to analyze gene expression in different diets, and GAPDH and 28S rRNA were suitable for various pesticide conditions. Overall, this research offers a complete list of reference genes from L. invasa for precise analysis of target gene expression, which can improve the trustworthiness of RT-qPCR and lay the foundation for further investigations into the gene function of this pest. Full article

(This article belongs to the Special Issue Insect Bioinformatics)

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20 pages, 4294 KiB

Open AccessEditor’s ChoiceArticle

Review of Kissing Bugs (Hemiptera: Reduviidae: Triatominae) from China with Descriptions of Two New Species

by Yisheng Zhao, Mingyuan Fan, Hu Li and Wanzhi Cai

Insects 2023, 14(5), 450; https://doi.org/10.3390/insects14050450 - 10 May 2023

Cited by 31 | Viewed by 6747

Abstract

Triatominae, the only blood-sucking subfamily in Reduviidae, are the vectors of Chagas disease. The majority of them are distributed in the Americas, while the diversity in China has been underestimated, as only two species have been recorded. Here, we describe two new species [...] Read more.

Triatominae, the only blood-sucking subfamily in Reduviidae, are the vectors of Chagas disease. The majority of them are distributed in the Americas, while the diversity in China has been underestimated, as only two species have been recorded. Here, we describe two new species from China, Triatoma picta Zhao & Cai sp. nov. and T. atrata Zhao & Cai sp. nov., and provide a redescription of T. sinica Hsiao, 1965, along with remarks on T. rubrofasciata (De Geer, 1773). To facilitate the identification, we include photos, especially of genitalia, as well as a distribution map and a key to Chinese triatomines. We calculated the pairwise genetic distances between 23 Triatoma species, which further supported the validity of these new species. We anticipate that our taxonomic review will be useful for identifying Chinese Triatominae. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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12 pages, 1622 KiB

Open AccessEditor’s ChoiceArticle

Giant Sex Chromosomes in Omophoita Species (Coleoptera, Chrysomelidae): Structural and Evolutionary Relationships Revealed by Zoo-FISH and Comparative Genomic Hybridization (CGH)

by Jhon A. D. Vidal, Francisco de M. C. Sassi, Renata L. R. de Moraes, Roberto F. Artoni, Thomas Liehr, Marcelo B. Cioffi and Mara C. de Almeida

Insects 2023, 14(5), 440; https://doi.org/10.3390/insects14050440 - 4 May 2023

Cited by 3 | Viewed by 3037

Abstract

The beetles of the subtribe Oedionychina (Chrysomelidae, Alticinae) are the only ones that have the atypical giant and achiasmatic sex chromosomes, which are substantially larger than the autosomes. Previous cytogenetic analyses suggest a large accumulation of repetitive DNA in the sex chromosomes. In [...] Read more.

The beetles of the subtribe Oedionychina (Chrysomelidae, Alticinae) are the only ones that have the atypical giant and achiasmatic sex chromosomes, which are substantially larger than the autosomes. Previous cytogenetic analyses suggest a large accumulation of repetitive DNA in the sex chromosomes. In this study, we examined the similarity of X and Y chromosomes in four Omophoita species and compared genomic differentiation to better understand the evolutionary process and the giant sex chromosomes origin. Intraspecific genomic comparation using male and female genomes of O. octoguttata and interespecific analyses using genomic DNA of O. octoguttata, O. sexnotata, O. magniguttis, and O. personata were performed. In addition, whole chromosome painting (WCP) experiments were performed with X and Y chromosome probes of O. octogutatta. CGH analysis revealed great genomic similarity between the sexes and a sex-specific region on the Y chromosome, and interspecific analysis revealed a genomic divergence between species. In contrast, WCP results revealed that the sex chromosomes of O. octoguttata have high intra- and interspecific similarity with the studied species. Our data support a common origin under the canonical evolution of the sex chromosomes in this group, as they have high genomic similarity between them. Full article

(This article belongs to the Section Insect Molecular Biology and Genomics)

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8 pages, 537 KiB

Open AccessEditor’s ChoiceCommunication

Rescuing the Inhibitory Effect of the Salivary Gland Hypertrophy Virus of Musca domestica on Mating Behavior

by Marissa Gallagher, Arianna Ramirez, Christopher J. Geden and John G. Stoffolano, Jr.

Insects 2023, 14(5), 416; https://doi.org/10.3390/insects14050416 - 27 Apr 2023

Viewed by 2719

Abstract

Infection with salivary gland hypertrophy virus (MdSGHV) of Musca domestica prevents female flies from accepting copulation attempts by healthy or virus-infected males. This study focused on supplemental hormonal rescue therapy for mating behavior in virus-infected female house flies. The inhibitory effect [...] Read more.

Infection with salivary gland hypertrophy virus (MdSGHV) of Musca domestica prevents female flies from accepting copulation attempts by healthy or virus-infected males. This study focused on supplemental hormonal rescue therapy for mating behavior in virus-infected female house flies. The inhibitory effect of the virus on mating behavior in females injected with MdSGHV was reversed by hormonal therapy in the form of octopamine injections, topical application of methoprene, or both therapies combined along with 20-hydroxyecdysone. Infected females whose mating responsiveness had been restored continued to have other viral pathologies associated with infection such as hypertrophy of the salivary glands and a lack of ovarian development. Full article

(This article belongs to the Special Issue Fly Biology, Ecology, Behavior and Management)

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11 pages, 2304 KiB

Open AccessEditor’s ChoiceArticle

Host Specificity in Canopy Nesting Forms of Ochrogaster lunifer: The Larger Children Do Not Care

by Julianne Farrell, Myron P. Zalucki and Andrea Battisti

Insects 2023, 14(5), 420; https://doi.org/10.3390/insects14050420 - 27 Apr 2023

Cited by 2 | Viewed by 1681

Abstract

The ‘mother knows best’ hypothesis is tested in a species of processionary moth feeding on acacias and eucalypts in Australia. The processionary moth Ochrogaster lunifer (Lepidoptera: Notodontidae; Thaumetopoeinae) is a social caterpillar living in large colonies on a number of tree and shrub [...] Read more.

The ‘mother knows best’ hypothesis is tested in a species of processionary moth feeding on acacias and eucalypts in Australia. The processionary moth Ochrogaster lunifer (Lepidoptera: Notodontidae; Thaumetopoeinae) is a social caterpillar living in large colonies on a number of tree and shrub species. Five nesting types—canopy, trunk, tree-hugger, hanging, and ground—have been described, and this study deals with canopy nesters on various species of acacias (Acacia spp.) and eucalypts (Eucalyptus spp. and Corymbia spp.). Reciprocal transplant experiments conducted over three years confirm the ‘mother knows best’ hypothesis, as colonies performed better on the natal host plant than on the recipient ones. Young first instar larvae were less likely to establish on a non-natal host than the mature larvae, and all acacia-sourced canopy egg masses failed to establish on eucalypts. Large larvae were able to establish on transplant hosts. This suggests a strong preference–performance link at what is likely a species level, confirming preliminary results recently published on genetic divergence. Canopy nesting forms also have a lower realised fecundity than the ground nesting form on acacias from the same geographic area, but higher than another canopy nesting form from western Australia. Further observations on ecological and genetic traits are required to draw conclusions about the separation of lineages in the canopy nesting form of O. lunifer, by including populations from other parts of the range for both the herbivore and the host plants. Full article

(This article belongs to the Topic Arthropod Biodiversity: Ecological and Functional Aspects)

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12 pages, 2923 KiB

Open AccessEditor’s ChoiceArticle

Is Every Vein a Real Vein? Cross-Section of the Wing of Matsucoccus Pini (Insecta, Hemiptera, Coccoidea: Matsucoccidae)

by Barbara Franielczyk-Pietyra, Małgorzata Kalandyk-Kołodziejczyk and Jowita Drohojowska

Insects 2023, 14(4), 390; https://doi.org/10.3390/insects14040390 - 17 Apr 2023

Cited by 3 | Viewed by 2021

Abstract

Wings of Matsucoccus pini males were studied. Using light and scanning electron microscopes, both sides of the wing membrane, dorsal and ventral, were examined. The presence of only one vein in the common stem was confirmed by the cross-section, namely the radius. The [...] Read more.

Wings of Matsucoccus pini males were studied. Using light and scanning electron microscopes, both sides of the wing membrane, dorsal and ventral, were examined. The presence of only one vein in the common stem was confirmed by the cross-section, namely the radius. The elements regarded as subcostal and medial veins were not confirmed as veins. On the dorsal side of the wings, a cluster of campaniform sensilla is shown for the first time in the family Matsucoccidae, through SEM, and two additional sensilla were found on the ventral side. There was a lack of alar setae, microtrichia as well as pterostigma. This is the second cross-section of the wing among scale insects. We propose the following nomenclature for the wings in the family Matsucoccidae: subcostal thickening (sct), radius (R), median fold (med) and anal fold (af). Full article

(This article belongs to the Special Issue The Outlook of Insect Study for Generation of New Approaches in Science and Practice)

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19 pages, 7581 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Cimicids of Medical and Veterinary Importance

by Fatima Zohra Hamlili, Jean Michel Bérenger and Philippe Parola

Insects 2023, 14(4), 392; https://doi.org/10.3390/insects14040392 - 17 Apr 2023

Cited by 6 | Viewed by 11031

Abstract

Members of the Cimicidae family are significant pests for mammals and birds, and they have attracted medical and veterinary interest. A number of recent studies have investigated bed bugs, due to their dramatic resurgence all over the world. Indeed, bed bugs are of [...] Read more.

Members of the Cimicidae family are significant pests for mammals and birds, and they have attracted medical and veterinary interest. A number of recent studies have investigated bed bugs, due to their dramatic resurgence all over the world. Indeed, bed bugs are of significant public health and socioeconomic importance since they lead to financial burdens and dermatological complications and may have mental and psychological consequences. It is important to note that certain cimicids with a preference for specific hosts (birds and bats) use humans as an alternative host, and some cimicids have been reported to willingly feed on human blood. In addition, members of the Cimicidae family can lead to economic burdens and certain species are the vectors for pathogens responsible for diseases. Therefore, in this review, we aim to provide an update on the species within the Cimicidae family that have varying medical and veterinary impacts, including their distribution and their associated microorganisms. Various microbes have been documented in bed bugs and certain important pathogens have been experimentally documented to be passively transmitted by bed bugs, although no conclusive evidence has yet associated them with epidemiological outbreaks. Additionally, among the studied cimicids (bat bugs, chicken bugs, and swallow bugs), only the American swallow bug has been considered to be a vector of several arboviruses, although there is no proven evidence of transmission to humans or animals. Further studies are needed to elucidate the reason that certain species in the Cimicidae family cannot be biologically involved in transmission to humans or animals. Additional investigations are also required to better understand the roles of Cimicidae family members in the transmission of human pathogens in the field. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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24 pages, 7311 KiB

Open AccessEditor’s ChoiceArticle

DNA Barcoding of the Palaearctic Elfin Butterflies (Lepidoptera, Lycaenidae) with a Description of Four New Species from Vietnam

by Anatoly Krupitsky, Nazar Shapoval and Galina Shapoval

Insects 2023, 14(4), 352; https://doi.org/10.3390/insects14040352 - 2 Apr 2023

Cited by 5 | Viewed by 2947

Abstract

Phylogenetic analysis is provided for the first time for 12 species of Palaearctic elfin butterflies, members of the previously recognized genera Ahlbergia Bryk, 1947, Cissatsuma Johnson, 1992, and Novosatsuma Johnson, 1992, based on the barcoding region of the mitochondrial cytochrome C oxidase subunit [...] Read more.

Phylogenetic analysis is provided for the first time for 12 species of Palaearctic elfin butterflies, members of the previously recognized genera Ahlbergia Bryk, 1947, Cissatsuma Johnson, 1992, and Novosatsuma Johnson, 1992, based on the barcoding region of the mitochondrial cytochrome C oxidase subunit I gene (COI). Comparison of the COI barcodes revealed very low levels of genetic divergence between the species of the Palaearctic elfin butterflies and Callophrys Billberg, 1820 sensu stricto. COI-based phylogeny revealed that Palaearctic Callophrys and the Palaearctic elfin butterflies, except Cissatsuma, are polyphyletic. Four new sympatric species, namely, Callophrys (Ahlbergia) hmong sp. n., C. (A.) tay sp. n., Callophrys (Cissatsuma) devyatkini sp. n. and C. (A.) dao sp. n. are described from Ha Giang Province, North Vietnam, based on wing colouration, the morphologies of the male and female genitalia, and differences in COI sequences. Discovery of the new species expands the distribution range of the group towards the southeast, beyond the Palaearctic region. Full article

(This article belongs to the Special Issue Systematics, Ecology and Evolution of Lepidoptera)

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17 pages, 2986 KiB

Open AccessEditor’s ChoiceArticle

Economic Benefits from Managing Coffee Berry Borer (Hypothenemus hampei) in Hawaii

by Donna Lee, Melissa A. Johnson, Luis F. Aristizábal, Suzanne Shriner, Catherine Chan, Susan Miyasaka and Marisa Wall

Insects 2023, 14(4), 350; https://doi.org/10.3390/insects14040350 - 1 Apr 2023

Cited by 8 | Viewed by 2574

Abstract

Coffee berry borer (CBB) is considered the most damaging insect pest of coffee worldwide. CBB was first detected on Hawai‘i Island in 2010, and quickly spread throughout the state’s coffee-growing regions. With the introduction of this pest, Hawaii’s small yet economically important coffee [...] Read more.

Coffee berry borer (CBB) is considered the most damaging insect pest of coffee worldwide. CBB was first detected on Hawai‘i Island in 2010, and quickly spread throughout the state’s coffee-growing regions. With the introduction of this pest, Hawaii’s small yet economically important coffee industry was changed forever with growers facing significantly higher production and labor costs, as well as decreased yield and coffee quality. We assessed the economic benefits of managing CBB based on three strategies that emerged in Hawaii over the last decade: (1) the use of the entomopathogenic fungus Beauveria bassiana alone, (2) early integrated pest management (IPM), which combined monitoring and sanitation with spraying B. bassiana, and (3) research-based IPM, which focused on CBB biology in Hawaii, optimization of monitoring, B. bassiana applications, and cultural controls. From 2011 to 2021, the economic benefits from managing CBB were USD 52 million using B. bassiana alone, USD 69 million from early IPM, and USD 130 million from research-based IPM, for a total of USD 251 million from all management. Our findings suggest that all types of management provide economic benefits to Hawaii growers, but management strategies based on Hawaii-specific research have provided the greatest gains in coffee yield, price, and revenue. Full article

(This article belongs to the Special Issue Biology, Ecology, and Management of the Coffee Berry Borer (Hypothenemus hampei))

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15 pages, 4147 KiB

Open AccessEditor’s ChoiceArticle

Winners and Losers: Cordulegaster Species under the Pressure of Climate Change

by Judit Fekete, Geert De Knijf, Marco Dinis, Judit Padisák, Pál Boda, Edvárd Mizsei and Gábor Várbíró

Insects 2023, 14(4), 348; https://doi.org/10.3390/insects14040348 - 31 Mar 2023

Cited by 8 | Viewed by 2538

Abstract

(1) Bioclimatic factors have a proven effect on species distributions in terrestrial, marine, or freshwater ecosystems. Because of anthropogenic effects, the changes in these variables are accelerated; thus, the knowledge of the impact has great importance from a conservation point of view. Two [...] Read more.

(1) Bioclimatic factors have a proven effect on species distributions in terrestrial, marine, or freshwater ecosystems. Because of anthropogenic effects, the changes in these variables are accelerated; thus, the knowledge of the impact has great importance from a conservation point of view. Two endemic dragonflies, the Balkan Goldenring (Cordulegaster heros) and the Two-Toothed Goldenring (C. bidentata), confined to the hilly and mountainous regions in Europe, are classified as “Near Threatened” according to the IUCN Red List. (2) Modeling the potential occurrence of both species under present and future climatic conditions provides a more accurate picture of the most suitable areas. The models were used to predict the responses of both species to 6 different climate scenarios for the year 2070. (3) We revealed which climatic and abiotic variables affect them the most and which areas are the most suitable for the species. We calculated how future climatic changes would affect the range of suitable areas for the two species. (4) According to our results, the suitable area for Cordulegaster bidentata and C. heros are strongly influenced by bioclimatic variables and showed an upward shift toward high elevations. The models predict a loss of suitable area in the case of C. bidentata and a large gain in the case of C. heros. Full article

(This article belongs to the Special Issue Climate Change and Insects)

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12 pages, 25064 KiB

Open AccessEditor’s ChoiceArticle

A Novel Model of Pathogenesis of Metarhizium anisopliae Propagules through the Midguts of Aedes aegypti Larvae

by Ricardo de Oliveira Barbosa Bitencourt, Jacenir Reis dos Santos-Mallet, Carl Lowenberger, Adriana Ventura, Patrícia Silva Gôlo, Vânia Rita Elias Pinheiro Bittencourt and Isabele da Costa Angelo

Insects 2023, 14(4), 328; https://doi.org/10.3390/insects14040328 - 28 Mar 2023

Cited by 15 | Viewed by 3173

Abstract

We assessed the effect of the entomopathogenic fungus Metarhizium anisopliae against Aedes aegypti. Conidia of M. anisopliae strains CG 489, CG 153, and IBCB 481 were grown in Adamek medium under different conditions to improve blastospore production. Mosquito larvae were exposed to [...] Read more.

We assessed the effect of the entomopathogenic fungus Metarhizium anisopliae against Aedes aegypti. Conidia of M. anisopliae strains CG 489, CG 153, and IBCB 481 were grown in Adamek medium under different conditions to improve blastospore production. Mosquito larvae were exposed to blastospores or conidia of the three fungal strains at 1 × 10⁷ propagules mL⁻¹. M. anisopliae IBCB 481 and CG 153 reduced larval survival by 100%, whereas CG 489 decreased survival by about 50%. Blastospores of M. anisopliae IBCB 481 had better results in lowering larval survival. M. anisopliae CG 489 and CG 153 reduced larval survival similarly. For histopathology (HP) and scanning electron microscopy (SEM), larvae were exposed to M. anisopliae CG 153 for 24 h or 48 h. SEM confirmed the presence of fungi in the digestive tract, while HP confirmed that propagules reached the hemocoel via the midgut, damaged the peritrophic matrix, caused rupture and atrophy of the intestinal mucosa, caused cytoplasmic disorganization of the enterocytes, and degraded the brush border. Furthermore, we report for the first time the potential of M. anisopliae IBCB 481 to kill Ae. aegypti larvae and methods to improve the production of blastospores. Full article

(This article belongs to the Section Insect Behavior and Pathology)

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12 pages, 2233 KiB

Open AccessEditor’s ChoiceArticle

Factors Guiding the Orientation of Nymphal Spotted Lanternfly, Lycorma delicatula

by Miriam F. Cooperband, Jacob D. Wickham and Melissa L. Warden

Insects 2023, 14(3), 279; https://doi.org/10.3390/insects14030279 - 11 Mar 2023

Cited by 8 | Viewed by 3092

Abstract

A mark–release–recapture experiment was conducted to evaluate the orientation of spotted lanternfly (SLF) Lycorma delicatula White (Hemiptera: Fulgoridae) nymphs when released equidistant between two trees. The experiment was repeated weekly for eight weeks in a heavily infested area with mature tree-of-heaven Ailanthus altissima [...] Read more.

A mark–release–recapture experiment was conducted to evaluate the orientation of spotted lanternfly (SLF) Lycorma delicatula White (Hemiptera: Fulgoridae) nymphs when released equidistant between two trees. The experiment was repeated weekly for eight weeks in a heavily infested area with mature tree-of-heaven Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) planted in rows as ornamental street trees in Beijing, China. One tree in each pair received a methyl salicylate lure, and the lure was rotated between trees every week as it aged. Two additional independent variables for each tree were also analyzed: size and SLF population density. Marked–released SLF significantly chose trees with higher SLF population density over trees with lower density populations, and they also chose larger trees significantly more than smaller trees. Population density and tree size were better predictors of attraction than lures, but when those factors were controlled, SLF significantly chose trees with methyl salicylate lures over control trees for the first 4 weeks of lure life. Wild SLF distribution was assessed weekly, revealing strong aggregation in first and second instars that diminished with development to the third and fourth instars. Thus, nymphal SLF aggregate, and orientation is strongly guided by the presence of other SLF and tree size. Full article

(This article belongs to the Special Issue Invasive Arthropod Pests - Volume II)

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16 pages, 1274 KiB

Open AccessEditor’s ChoiceArticle

Physical Properties of Substrates as a Driver for Hermetia illucens (L.) (Diptera: Stratiomyidae) Larvae Growth

by Wael Yakti, Marcus Müller, Martina Klost, Inga Mewis, Dennis Dannehl and Christian Ulrichs

Insects 2023, 14(3), 266; https://doi.org/10.3390/insects14030266 - 8 Mar 2023

Cited by 35 | Viewed by 5080

Abstract

The growth and nutritional profile of the black soldier fly larvae (BSFL) is usually investigated and compared when the larvae feed on substrates that differ in the chemical composition as well as physical properties. This study compares BSFL growth on substrates that differ [...] Read more.

The growth and nutritional profile of the black soldier fly larvae (BSFL) is usually investigated and compared when the larvae feed on substrates that differ in the chemical composition as well as physical properties. This study compares BSFL growth on substrates that differ primarily in physical properties. This was achieved by using various fibres in the substrates. In the first experiment, two substrates with 20% or 14% chicken feed were mixed with three fibres (cellulose, lignocellulose, or straw). In the second experiment, the growth of BSFL was compared with a 17% chicken feed substrate that additionally contained straw with different particle sizes. We show that the substrate texture properties values did not influence the BSFL growth, but the bulk density of the fibre component did. The substrate mixed with cellulose led to higher larvae growth over time in comparison to substrates with higher bulk density fibres. BSFL grown on the substrate mixed with cellulose reached their maximum weight in 6 days instead of 7. Neither the fibres nor the nutrient level changed the crude protein content of BSFL and the values ranged between 33.5% and 38.3%, but an interaction between the fibre and nutrient level was observed. The size of straw particles in the substrates influenced the BSFL growth and led to a 26.78% difference in Ca concentration, a 12.04% difference in Mg concentration, and a 35.34% difference in P concentration. Our findings indicate that the BSFL-rearing substrates can be optimised by changing the fibre component or its particle size. This can improve the survival rate, reduce the cultivation time needed to reach the maximum weight, and alter the chemical composition of BSFL. Full article

(This article belongs to the Special Issue Insects at the Center of the Green Transition)

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9 pages, 261 KiB

Open AccessEditor’s ChoiceArticle

Magnitude and Extent of Helicoverpa zea Resistance Levels to Cry1Ac and Cry2Ab2 across the Southeastern USA

by Dominic Reisig, G. David Buntin, Jeremy K. Greene, Silvana V. Paula-Moraes, Francis Reay-Jones, Phillip Roberts, Ron Smith and Sally V. Taylor

Insects 2023, 14(3), 262; https://doi.org/10.3390/insects14030262 - 7 Mar 2023

Cited by 11 | Viewed by 2454

Abstract

After resistance is first detected, continued resistance monitoring can inform decisions on how to effectively manage resistant populations. We monitored for resistance to Cry1Ac (2018 and 2019) and Cry2Ab2 (2019) from southeastern USA populations of Helicoverpa zea. We collected larvae from various [...] Read more.

After resistance is first detected, continued resistance monitoring can inform decisions on how to effectively manage resistant populations. We monitored for resistance to Cry1Ac (2018 and 2019) and Cry2Ab2 (2019) from southeastern USA populations of Helicoverpa zea. We collected larvae from various plant hosts, sib-mated the adults, and tested neonates using diet-overlay bioassays and compared them to susceptible populations for resistance estimates. We also compared LC₅₀ values with larval survival, weight and larval inhibition at the highest dose tested using regression, and found that LC₅₀ values were negatively correlated with survival for both proteins. Finally, we compared resistance rations between Cry1Ac and Cry2Ab2 during 2019. Some populations were resistant to Cry1Ac, and most were resistant to CryAb2; Cry1Ac resistance ratios were lower than Cry2Ab2 during 2019. Survival was positively correlated with larval weight inhibition for Cry2Ab. This contrasts with other studies in both the mid-southern and southeastern USA, where resistance to Cry1Ac, Cry1A.105, and Cry2Ab2 increased over time and was found in a majority of populations. This indicates that cotton expressing Cry proteins in the southeastern USA was at variable risk for damage in this region. Full article

(This article belongs to the Special Issue Resistance of Pests to Insecticidal Proteins from Bacillus thuringiensis (Bt))

13 pages, 1687 KiB

Open AccessEditor’s ChoiceArticle

Cicadomorpha Community (Hemiptera: Auchenorrhyncha) in Portuguese Vineyards with Notes of Potential Vectors of Xylella fastidiosa

by Isabel Rodrigues, Maria Teresa Rebelo, Paula Baptista and José Alberto Pereira

Insects 2023, 14(3), 251; https://doi.org/10.3390/insects14030251 - 2 Mar 2023

Cited by 5 | Viewed by 2716

Abstract

Cicadomorpha (Hemiptera) insects are currently responsible for a growing negative impact on the agricultural economy due to their ability to directly damage crops or through the capacity to act as vectors for plant pathogens. The phytopathogenic bacterium Xylella fastidiosa, the causal agent [...] Read more.

Cicadomorpha (Hemiptera) insects are currently responsible for a growing negative impact on the agricultural economy due to their ability to directly damage crops or through the capacity to act as vectors for plant pathogens. The phytopathogenic bacterium Xylella fastidiosa, the causal agent of Pierce’s disease in vineyards, is exclusively transmitted by insects of this infraorder. Therefore, knowledge of the Cicadomorpha species and understanding their biology and ecology is crucial. In this work, in 2018 and 2019, the canopy and inter-row vegetation of 35 vineyards distributed in mainland Portugal were sampled to investigate species composition, richness, and diversity of the Cicadomorpha community, with a special focus given to vectors and potential vectors of X. fastidiosa. A total of 11,834 individuals were collected, 3003 in 2018 and 8831 in 2019. Of the 81 species/morphospecies identified, only five are considered vectors or potential vectors of this pathogen, namely, Cicadella viridis (Linnaeus, 1758), Philaenus spumarius (Linnaeus, 1758), Neophilaenus campestris (Fallén, 1805), Lepyronia coleoptrata (Linnaeus, 1758), and N. lineatus (Linnaeus, 1758). Cicadella viridis was the most abundant xylem sap feeder, followed by P. spumarius. In addition, Cicadomorpha that cause direct damage to vines and vectors of grapevine yellows’ phytoplasmas were also collected and identified in the sampled vineyards. The results suggested that vectors and potential vectors of X. fastidiosa and a large proportion of the population of Cicadomorpha have a positive correction with inter-row vegetation. Full article

(This article belongs to the Special Issue Insect Vectors of Plant Diseases)

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12 pages, 3333 KiB

Open AccessEditor’s ChoiceArticle

FibH Gene Complete Sequences (FibHome) Revealed Silkworm Pedigree

by Wei Lu, Tong Zhang, Quan Zhang, Na Zhang, Ling Jia, Sanyuan Ma and Qingyou Xia

Insects 2023, 14(3), 244; https://doi.org/10.3390/insects14030244 - 28 Feb 2023

Cited by 4 | Viewed by 2218

Abstract

The highly repetitive and variable fibroin heavy chain (FibH) gene can be used as a silkworm identification; however, only a few complete FibH sequences are known. In this study, we extracted and examined 264 FibH gene complete sequences (FibHome) from a [...] Read more.

The highly repetitive and variable fibroin heavy chain (FibH) gene can be used as a silkworm identification; however, only a few complete FibH sequences are known. In this study, we extracted and examined 264 FibH gene complete sequences (FibHome) from a high-resolution silkworm pan-genome. The average FibH lengths of the wild silkworm, local, and improved strains were 19,698 bp, 16,427 bp, and 15,795 bp, respectively. All FibH sequences had a conserved 5′ and 3′ terminal non-repetitive (5′ and 3′ TNR, 99.74% and 99.99% identity, respectively) sequence and a variable repetitive core (RC). The RCs differed greatly, but they all shared the same motif. During domestication or breeding, the FibH gene mutated with hexanucleotide (GGTGCT) as the core unit. Numerous variations existed that were not unique to wild and domesticated silkworms. However, the transcriptional factor binding sites, such as fibroin modulator-binding protein, were highly conserved and had 100% identity in the FibH gene’s intron and upstream sequences. The local and improved strains with the same FibH gene were divided into four families using this gene as a marker. Family I contained a maximum of 62 strains with the optional FibH (Opti-FibH, 15,960 bp) gene. This study provides new insights into FibH variations and silkworm breeding. Full article

(This article belongs to the Section Insect Systematics, Phylogeny and Evolution)

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19 pages, 3025 KiB

Open AccessEditor’s ChoiceArticle

Implications of the Niche Partitioning and Coexistence of Two Resident Parasitoids for Drosophila suzukii Management in Non-Crop Areas

by María Josefina Buonocore Biancheri, Segundo Ricardo Núñez-Campero, Lorena Suárez, Marcos Darío Ponssa, Daniel Santiago Kirschbaum, Flávio Roberto Mello Garcia and Sergio Marcelo Ovruski

Insects 2023, 14(3), 222; https://doi.org/10.3390/insects14030222 - 23 Feb 2023

Cited by 10 | Viewed by 3779

Abstract

Understanding the mechanisms associated with the coexistence of competing parasitoid species is critical in approaching any biological control strategy against the globally invasive pest spotted-wing drosophila (=SWD), Drosophila suzukii (Matsumura). This study assessed the coexistence of two resident pupal parasitoids, Trichopria anastrephae Lima [...] Read more.

Understanding the mechanisms associated with the coexistence of competing parasitoid species is critical in approaching any biological control strategy against the globally invasive pest spotted-wing drosophila (=SWD), Drosophila suzukii (Matsumura). This study assessed the coexistence of two resident pupal parasitoids, Trichopria anastrephae Lima and Pachycrepoideus vindemiae Rondani, in SWD-infested fruit, in disturbed wild vegetation areas of Tucumán, northwestern Argentina, based on niche segregation. Drosophilid puparia were collected between December/2016 and April/2017 from three different pupation microhabitats in fallen feral peach and guava. These microhabitats were “inside flesh (mesocarp)”, “outside flesh”, but associated with the fruit, and “soil”, i.e., puparia buried close to fruit. Saprophytic drosophilid puparia (=SD) belonging to the Drosophila melanogaster group and SWD were found in all tested microhabitats. SD predominated in both inside and outside flesh, whereas SWD in soil. Both parasitoids attacked SWD puparia. However, T. anastrephae emerged mainly from SD puparia primarily in the inside flesh, whereas P. vindemiae mostly foraged SWD puparia in less competitive microhabitats, such as in the soil or outside the flesh. Divergence in host choice and spatial patterns of same-resource preferences between both parasitoids may mediate their coexistence in non-crop environments. Given this scenario, both parasitoids have potential as SWD biocontrol agents. Full article

(This article belongs to the Special Issue Fly Biology, Ecology, Behavior and Management)

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17 pages, 705 KiB

Open AccessEditor’s ChoiceReview

Fitness Costs and Incomplete Resistance Associated with Delayed Evolution of Practical Resistance to Bt Crops

by Yves Carrière and Bruce E. Tabashnik

Insects 2023, 14(3), 214; https://doi.org/10.3390/insects14030214 - 21 Feb 2023

Cited by 15 | Viewed by 2952

Abstract

Insect pests are increasingly evolving practical resistance to insecticidal transgenic crops that produce Bacillus thuringiensis (Bt) proteins. Here, we analyzed data from the literature to evaluate the association between practical resistance to Bt crops and two pest traits: fitness costs and incomplete resistance. [...] Read more.

Insect pests are increasingly evolving practical resistance to insecticidal transgenic crops that produce Bacillus thuringiensis (Bt) proteins. Here, we analyzed data from the literature to evaluate the association between practical resistance to Bt crops and two pest traits: fitness costs and incomplete resistance. Fitness costs are negative effects of resistance alleles on fitness in the absence of Bt toxins. Incomplete resistance entails a lower fitness of resistant individuals on a Bt crop relative to a comparable non-Bt crop. In 66 studies evaluating strains of nine pest species from six countries, costs in resistant strains were lower in cases with practical resistance (14%) than without practical resistance (30%). Costs in F₁ progeny from crosses between resistant and susceptible strains did not differ between cases with and without practical resistance. In 24 studies examining seven pest species from four countries, survival on the Bt crop relative to its non-Bt crop counterpart was higher in cases with practical resistance (0.76) than without practical resistance (0.43). Together with previous findings showing that the nonrecessive inheritance of resistance is associated with practical resistance, these results identify a syndrome associated with practical resistance to Bt crops. Further research on this resistance syndrome could help sustain the efficacy of Bt crops. Full article

(This article belongs to the Special Issue Resistance of Pests to Insecticidal Proteins from Bacillus thuringiensis (Bt))

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17 pages, 1378 KiB

Open AccessEditor’s ChoiceReview

Dynamic Roles of Insect Carboxyl/Cholinesterases in Chemical Adaptation

by Casey Cruse, Timothy Walter Moural and Fang Zhu

Insects 2023, 14(2), 194; https://doi.org/10.3390/insects14020194 - 16 Feb 2023

Cited by 39 | Viewed by 5675

Abstract

Insects have evolved several intricate defense mechanisms to adapt to their chemical environment. Due to their versatile capabilities in hydrolytic biotransformation, insect carboxyl/cholinesterases (CCEs) play vital roles in the development of pesticide resistance, facilitating the adaptation of insects to their host plants, and [...] Read more.

Insects have evolved several intricate defense mechanisms to adapt to their chemical environment. Due to their versatile capabilities in hydrolytic biotransformation, insect carboxyl/cholinesterases (CCEs) play vital roles in the development of pesticide resistance, facilitating the adaptation of insects to their host plants, and manipulating insect behaviors through the olfaction system. CCEs confer insecticide resistance through the mechanisms of qualitative or quantitative changes of CCE-mediated enhanced metabolism or target-site insensitivity, and may contribute to the host plant adaptation. CCEs represent the first odorant-degrading enzymes (ODEs) discovered to degrade insect pheromones and plant odors and remain the most promising ODE candidates. Here, we summarize insect CCE classification, currently characterized insect CCE protein structure characteristics, and the dynamic roles of insect CCEs in chemical adaptation. Full article

(This article belongs to the Special Issue The Evolution of Pesticide Resistance)

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18 pages, 1993 KiB

Open AccessEditor’s ChoiceArticle

Hemp Waste as a Substrate for Hermetia illucens (L.) (Diptera: Stratiomyidae) and Tenebrio molitor L. (Coleoptera: Tenebrionidae) Rearing

by Wael Yakti, Nadja Förster, Marcus Müller, Inga Mewis and Christian Ulrichs

Insects 2023, 14(2), 183; https://doi.org/10.3390/insects14020183 - 13 Feb 2023

Cited by 14 | Viewed by 4466

Abstract

The proper treatment of cannabis agricultural wastes can reduce the environmental impact of its cultivation and generate valuable products. This study aimed to test the potential of cannabis agricultural wastes as a substrate for the rearing of black soldier fly larvae (BSFL) and [...] Read more.

The proper treatment of cannabis agricultural wastes can reduce the environmental impact of its cultivation and generate valuable products. This study aimed to test the potential of cannabis agricultural wastes as a substrate for the rearing of black soldier fly larvae (BSFL) and yellow mealworms (MW). In the case of BSFL, replacing the fibre component (straw) in the substrate with the hemp waste can increase the nutritional value of the substrate and led to bigger larvae. The bigger larvae had lower P and Mg, and higher Fe and Ca. Crude protein also varied based on the size of larvae and/or the content of protein in the initial substrate, which was boosted by replacing straw with hemp material. No other cannabinoids than cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), and cannabidiol (CBD) were found in significant amounts in the larvae. In the case of MW, the larvae grew less on the hemp material in comparison to wheat bran. Replacing wheat bran with the hemp material led to smaller larvae with higher Ca, Fe, K, and crude protein content, but lower Mg and P values. No cannabinoids were detected in the MW fed with the hemp material. Full article

(This article belongs to the Special Issue Insects at the Center of the Green Transition)

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15 pages, 2777 KiB

Open AccessEditor’s ChoiceReview

Involvement of an Enhanced Immunity Mechanism in the Resistance to Bacillus thuringiensis in Lepidopteran Pests

by Zeyu Xiao, Xue Yao, Sufen Bai, Jizhen Wei and Shiheng An

Insects 2023, 14(2), 151; https://doi.org/10.3390/insects14020151 - 1 Feb 2023

Cited by 18 | Viewed by 4023

Abstract

Bacillus thuringiensis (Bt) is the safest, economically successful entomopathogen to date. It is extensively produced in transgenic crops or used in spray formulations to control Lepidopteran pests. The most serious threat to the sustainable usage of Bt is insect resistance. The [...] Read more.

Bacillus thuringiensis (Bt) is the safest, economically successful entomopathogen to date. It is extensively produced in transgenic crops or used in spray formulations to control Lepidopteran pests. The most serious threat to the sustainable usage of Bt is insect resistance. The resistance mechanisms to Bt toxins depend not only on alterations in insect receptors, but also on the enhancement of insect immune responses. In this work, we review the current knowledge of the immune response and resistance of insects to Bt formulations and Bt proteins, mainly in Lepidopteran pests. We discuss the pattern recognition proteins for recognizing Bt, antimicrobial peptides (AMPs) and their synthetic signaling pathways, the prophenoloxidase system, reactive oxygen species (ROS) generation, nodulation, encapsulation, phagocytosis, and cell-free aggregates, which are involved in immune response reactions or resistance to Bt. This review also analyzes immune priming, which contributes to the evolution of insect resistance to Bt, and puts forward strategies to improve the insecticidal activity of Bt formulations and manage insect resistance, targeting the insect immune responses and resistance. Full article

(This article belongs to the Special Issue Resistance of Pests to Insecticidal Proteins from Bacillus thuringiensis (Bt))

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14 pages, 4322 KiB

Open AccessEditor’s ChoiceArticle

Species Identification of the Major Japanese Encephalitis Vectors within the Culex vishnui Subgroup (Diptera: Culicidae) in Thailand Using Geometric Morphometrics and DNA Barcoding

by Tawee Saiwichai, Sedthapong Laojun, Tanawat Chaiphongpachara and Suchada Sumruayphol

Insects 2023, 14(2), 131; https://doi.org/10.3390/insects14020131 - 26 Jan 2023

Cited by 10 | Viewed by 2957

Abstract

Japanese encephalitis (JE) is a viral infection of the brain caused by the Japanese encephalitis virus, which spreads globally, particularly in 24 countries of Southeast Asia and the Western Pacific region. In Thailand, the primary vectors of JE are Cx. pseudovishnui, Cx. [...] Read more.

Japanese encephalitis (JE) is a viral infection of the brain caused by the Japanese encephalitis virus, which spreads globally, particularly in 24 countries of Southeast Asia and the Western Pacific region. In Thailand, the primary vectors of JE are Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui of the Cx. vishnui subgroup. The morphologies of three mosquito species are extremely similar, making identification challenging. Thus, geometric morphometrics (GM) and DNA barcoding were applied for species identification. The results of cross-validation reclassification revealed that the GM technique based on wing shape analysis had relatively high potential for distinguishing Cx. pseudovishnui, Cx. tritaeniorhynchus, and Cx. vishnui (total performance = 88.34% of correctly assigned individuals). While the DNA barcoding yielded excellent results in identifying these Culex species based on the DNA barcode gap (average intraspecific genetic distance = 0.78% ± 0.39% and average interspecific genetic distance = 6.14% ± 0.79%). However, in the absence of the required facilities for DNA barcoding, GM techniques can be employed in conjunction with morphological methods to enhance the reliability of species identification. Based on the results of this study, our approach can help guide efforts to identify members of the Cx. vishnui subgroup, which will be useful for the effective vector control of JE in Thailand. Full article

(This article belongs to the Section Medical and Livestock Entomology)

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30 pages, 39751 KiB

Open AccessEditor’s ChoiceArticle

Integrative Taxonomy Approach Reveals Cryptic Diversity within the Phoretic Pseudoscorpion Genus Lamprochernes (Pseudoscorpiones: Chernetidae)

by Jana Christophoryová, Katarína Krajčovičová, František Šťáhlavský, Stanislav Španiel and Vera Opatova

Insects 2023, 14(2), 122; https://doi.org/10.3390/insects14020122 - 25 Jan 2023

Cited by 9 | Viewed by 3540

Abstract

Pseudoscorpions represent an ancient, but homogeneous group of arachnids. The genus Lamprochernes comprises several morphologically similar species with wide and overlapping distributions. We implemented an integrative approach combining molecular barcoding (cox1), with cytogenetic and morphological analyses in order to assess species [...] Read more.

Pseudoscorpions represent an ancient, but homogeneous group of arachnids. The genus Lamprochernes comprises several morphologically similar species with wide and overlapping distributions. We implemented an integrative approach combining molecular barcoding (cox1), with cytogenetic and morphological analyses in order to assess species boundaries in European Lamprochernes populations. The results suggest ancient origins of Lamprochernes species accompanied by morphological stasis within the genus. Our integrative approach delimited three nominal Lamprochernes species and one cryptic lineage Lamprochernes abditus sp. nov. Despite its Oligocene origin, L. abditus sp. nov. can be distinguished from its closest relative only by molecular and cytogenetic differences, or alternatively, by a complex multivariate morphometric analysis involving other Lamprochernes species. The population structure and common haplotype sharing across geographically distant populations in most Lamprochernes species suggest that a phoretic manner of dispersal is efficient in this group. Full article

(This article belongs to the Section Other Arthropods and General Topics)

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10 pages, 250 KiB

Open AccessEditor’s ChoiceEditorial

Insecticides for Mosquito Control: Improving and Validating Methods to Strengthen the Evidence Base

by Rosemary Susan Lees, Christen Fornadel, Janneke Snetselaar, Joe Wagman and Angus Spiers

Insects 2023, 14(2), 116; https://doi.org/10.3390/insects14020116 - 23 Jan 2023

Cited by 7 | Viewed by 5067

Abstract

Efforts to eliminate vector-borne diseases, for example malaria which caused an estimated 619,000 deaths in 2021 [...] Full article

(This article belongs to the Special Issue Insecticides for Mosquito Control: Strengthening the Evidence Base)

16 pages, 291 KiB

Open AccessEditor’s ChoiceReview

A Review of Insect Pest Management in Vegetable Crop Production in Nigeria

by Thomas I. Ofuya, Adeyela I. Okunlola and George N. Mbata

Insects 2023, 14(2), 111; https://doi.org/10.3390/insects14020111 - 21 Jan 2023

Cited by 26 | Viewed by 12854

Abstract

Insect pest infestations and damage can limit the production of vegetables in the farming systems in Nigeria. This review looks at integrated insect pest management as a possible panacea for resolving insect pest issues in vegetable crops. The main vegetable crops which include [...] Read more.

Insect pest infestations and damage can limit the production of vegetables in the farming systems in Nigeria. This review looks at integrated insect pest management as a possible panacea for resolving insect pest issues in vegetable crops. The main vegetable crops which include okra, tomatoes, chilli peppers, cucumbers, green amaranth, carrots and onions are highlighted. The major insect pests of the various vegetables which include foliage beetles, caterpillars, aphids, fruit flies, stink bugs, and grasshoppers are also mentioned. The various control measures that have been empirically verified for the mitigation of the impact of these insect pests, including the application of synthetic insecticides, modification of agronomic practices, use of resistant varieties, application of botanicals, biological and mechanical controls, are discussed. Studies which have been carried out attempting to integrate two or more of the control strategies for better insect pest control are also reviewed. Strategies that can be put in place for the integrated pest management of vegetable insect pests in Nigeria are considered. Among the IPM (Integrated Pest Management) practices instituted for the mitigation of pest infestations on vegetable crops in Nigeria, intercropping of suitable vegetables in combination with the application of aqueous extracts of Azadirachta indica and Piper guineense seeds under good farm hygiene and sanitation proved to be most successful. Full article

(This article belongs to the Special Issue Arthropod Interactions and Pest Management in Fruit and Vegetable Crops)

21 pages, 1623 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Fermented or Floral? Developing a Generalized Food Bait Lure to Monitor Cutworm and Armyworm Moths (Lepidoptera: Noctuidae) in Field Crops

by Ronald E. Batallas and Maya L. Evenden

Insects 2023, 14(2), 106; https://doi.org/10.3390/insects14020106 - 19 Jan 2023

Cited by 9 | Viewed by 3343

Abstract

Cutworms and armyworms (Lepidoptera: Noctuidae) are a pest complex in North America that cause sporadic damage in field crops on the Canadian Prairies; however, no methods have been developed to reliably monitor population densities. Food-based semiochemicals attract both sexes of adult moths and [...] Read more.

Cutworms and armyworms (Lepidoptera: Noctuidae) are a pest complex in North America that cause sporadic damage in field crops on the Canadian Prairies; however, no methods have been developed to reliably monitor population densities. Food-based semiochemicals attract both sexes of adult moths and could be used to monitor multiple species with a single lure in a single trap. Here, we focus on enhancing the attractiveness of acetic acid and 3-methyl-1-butanol (AAMB) lures to redbacked cutworm (Euxoa ochrogaster) (RBC) and other noctuid pests. Experiments conducted in canola and wheat fields tested AAMB lures at different release rates, from different devices and in combination with other semiochemicals. High-release lures captured more females in canola, while low-release lures captured more males in wheat. Thus, crop volatiles may influence response to lures. Semiochemicals embedded in an inert matrix caught more RBC moths than semiochemicals released from Nalgene or polyethylene dispensers did. More RBC females were attracted to AAMB lures with 2-methyl-1-propanol than phenylacetaldehyde. Fermented volatiles appear to be a more reliable attractant than floral volatiles for these species. RBC moth antennae produced significant responses to all doses of phenylacetaldehyde tested in electroantennogram assays, but only to higher doses of acetic acid and 3-methyl-1-butanol. Physiological state of the RBC moths also influenced responsiveness to the tested semiochemical. Feeding status did not influence the antennal response to acetic acid and phenylacetaldehyde in either sex, but it increased the response to 3-methyl-1-butanol in females when fed. AAMB lures should be further developed to monitor RBC moths and other noctuid pests in field crops. Full article

(This article belongs to the Special Issue Chemical Communication in Insects: New Advances in IPM Strategies)

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16 pages, 2063 KiB

Open AccessEditor’s ChoiceArticle

Efficacy of Conventional and Organic Insecticides against Scaphoideus titanus: Field and Semi-Field Trials

by Stefan Cristian Prazaru, Lisa D’Ambrogio, Martina Dal Cero, Mirko Rasera, Giovanni Cenedese, Enea Guerrieri, Marika Pavasini, Nicola Mori, Francesco Pavan and Carlo Duso

Insects 2023, 14(2), 101; https://doi.org/10.3390/insects14020101 - 17 Jan 2023

Cited by 8 | Viewed by 5635

Abstract

Scaphoideus titanus is the main vector of phytoplasmas associated with Flavescence dorée (FD), one of the most serious threats to viticulture in many European countries. To minimize the spread of this disease, mandatory control measures against S. titanus were decided in Europe. In [...] Read more.

Scaphoideus titanus is the main vector of phytoplasmas associated with Flavescence dorée (FD), one of the most serious threats to viticulture in many European countries. To minimize the spread of this disease, mandatory control measures against S. titanus were decided in Europe. In the 1990s, the repeated application of insecticides (mainly organophosphates) proved to be an effective measure to control the vector and the related disease in north-eastern Italy. These insecticides and most of the neonicotinoids were recently banned from European viticulture. Serious FD issues detected in the recent years in northern Italy could be related to the use of less effective insecticides. Trials aimed at evaluating the efficacy of the most used conventional and organic insecticides in the control of S. titanus have been performed in semi-field and field conditions to test this hypothesis. In efficacy trials, carried out in four vineyards, etofenprox and deltamethrin proved to be the best conventional insecticides, while pyrethrins were the most impactful among organic insecticides. Insecticide residual activity was evaluated in semi-field and field conditions. Acrinathrin showed the most significant residual effects in both conditions. In semi-field trials, most of the pyrethroids were associated with good results in terms of residual activity. However, these effects declined in field conditions, probably due to high temperatures. Organic insecticides showed poor results in terms of residual efficacy. Implications of these results in the context of Integrated Pest Management in conventional and organic viticulture are discussed. Full article

(This article belongs to the Special Issue Insect Vectors of Plant Diseases)

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21 pages, 2309 KiB

Open AccessEditor’s ChoiceArticle

Precision Monitoring of Honey Bee (Hymenoptera: Apidae) Activity and Pollen Diversity during Pollination to Evaluate Colony Health

by Aimee C. McKinnon, Luke Collins, Jennifer L. Wood, Nick Murphy, Ashley E. Franks and Martin J. Steinbauer

Insects 2023, 14(1), 95; https://doi.org/10.3390/insects14010095 - 16 Jan 2023

Cited by 2 | Viewed by 4099

Abstract

Certain crops depend upon pollination services for fruit set, and, of these, almonds are of high value for Australia. Stressors, such as diseases, parasites, pesticides, and nutrition, can contribute to honey bee Apis mellifera L. colony decline, thereby reducing bee activity and pollination [...] Read more.

Certain crops depend upon pollination services for fruit set, and, of these, almonds are of high value for Australia. Stressors, such as diseases, parasites, pesticides, and nutrition, can contribute to honey bee Apis mellifera L. colony decline, thereby reducing bee activity and pollination efficiency. In Australia, field studies are required to monitor honey bee health and to ascertain whether factors associated with colony decline are impacting hives. We monitored honey bee colonies during and after pollination services of almond. Video surveillance technology was used to quantify bee activity, and bee-collected pollen was periodically tested for pesticide residues. Plant species diversity was also assessed using DNA metabarcoding of the pollen. Results showed that bee activity increased in almond but not in bushland. Residues detected included four fungicides, although the quantities were of low risk of oral toxicity to bees. Floral diversity was lower in the pollen collected by bees from almonds compared to bushland. However, diversity was higher at the onset and conclusion of the almond bloom, suggesting that bees foraged more widely when availability was low. Our findings suggest that commercial almond orchards may sustain healthier bee colonies compared to bushland in early spring, although the magnitude of the benefit is likely landscape-dependent. Full article

(This article belongs to the Section Social Insects and Apiculture)

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12 pages, 1541 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Intraguild Predation of Hippodamia variegata on Aphid Mummies in Cotton Field

by Shuying Dou, Bing Liu, Yangtian Liu, Jianping Zhang and Yanhui Lu

Insects 2023, 14(1), 81; https://doi.org/10.3390/insects14010081 - 13 Jan 2023

Cited by 9 | Viewed by 2453

Abstract

Intraguild predation among arthropod predators in agricultural ecosystems may have a negative impact on biological control. At present, there are few direct reports on trophic relationships among participants of predation in field groups. In this study, we measured the feeding choices of Hippodamia [...] Read more.

Intraguild predation among arthropod predators in agricultural ecosystems may have a negative impact on biological control. At present, there are few direct reports on trophic relationships among participants of predation in field groups. In this study, we measured the feeding choices of Hippodamia variegata (Goeze) towards mummies with different densities of Aphis gossypii Glover. The dynamics of the occurrence of mummies in the cotton field were investigated over 2017–2019. Singleplex PCR and multiplex PCR were used to detect the predation of 2090 H. variegata individuals on aphids and mummies in Xinjiang cotton field, which revealed the intraguild predation frequency between H. variegata and various parasitoids. There was no obvious feeding preference of H. variegata towards live aphids or mummies, which mainly depended on the relative density of prey. Among the four species of aphids detected in H. variegata, A. gossypii had a high detection rate and was the main prey source of the ladybeetle in the cotton filed. Mostly, ladybeetles consumed parasitoids through mummies, with 6.39% directly feeding on adult parasitoids. H. variegata had strong trophic links to both parasitoids and aphids. We established a food web of aphids–primary parasitoids–hyperparasitoids–H. variegata, which can be used to evaluate the pest control ability of H. variegata from a new perspective. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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32 pages, 7503 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

The Intranidal Myrmecophiles of the Maltese Islands with Notes on Messor Nests as Repositories of Biodiversity

by Thomas Cassar, Albena Lapeva-Gjonova and David Mifsud

Insects 2023, 14(1), 45; https://doi.org/10.3390/insects14010045 - 3 Jan 2023

Cited by 4 | Viewed by 3692

Abstract

The intranidal myrmecophilous arthropod fauna of the Maltese Islands is reviewed. Thirty species from nine orders are found to be obligate myrmecophiles, of which four species are recorded from the Maltese archipelago for the first time: Phrurolithus sp. (Araneae: Phrurolithidae), Pogonolaelaps canestrinii (Berlese, [...] Read more.

The intranidal myrmecophilous arthropod fauna of the Maltese Islands is reviewed. Thirty species from nine orders are found to be obligate myrmecophiles, of which four species are recorded from the Maltese archipelago for the first time: Phrurolithus sp. (Araneae: Phrurolithidae), Pogonolaelaps canestrinii (Berlese, 1904), Gymnolaelaps messor Joharchi, Halliday, Saboori & Kamali, 2011 and G. myrmecophilus (Berlese, 1892) (Mesostigmata: Laelapidae). Phrurolithus also represents the first record of the family Phrurolithidae in Malta. Notes on the biology and local distribution of each species are provided, including ant-myrmecophile associations, of which two appear to be previously unknown: the occurrence of Smynthurodes betae Westwood, 1849 (Hemiptera: Aphididae) in the nest of Plagiolepis pygmaea (Latreille, 1798) and Phrurolithus in the nest of Pheidole pallidula (Nylander, 1849). Fourteen additional species are found to be either only occasionally myrmecophilic, accidental ant-guests or potentially myrmecophilous, the latter remaining ambiguous due to a lack of knowledge of their biology. Of these, the family Caeculidae (Arachnida: Trombidiformes) represents a new record for the Maltese Islands, on the basis of Microcaeculus sp. occurring in a nest of Camponotus barbaricus Emery, 1905. Preliminary results indicate that Messor nests may be repositories of considerable myrmecophile diversity, with the most unique symbionts. Full article

(This article belongs to the Special Issue Arthropod Diversity and Conservation in Islands)

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16 pages, 2650 KiB

Open AccessEditor’s ChoiceArticle

Using Species Distribution Models (SDMs) to Estimate the Suitability of European Mediterranean Non-Native Area for the Establishment of Toumeyella Parvicornis (Hemiptera: Coccidae)

by Nicolò Di Sora, Roberto Mannu, Luca Rossini, Mario Contarini, Diego Gallego and Stefano Speranza

Insects 2023, 14(1), 46; https://doi.org/10.3390/insects14010046 - 3 Jan 2023

Cited by 12 | Viewed by 3802

Abstract

The pine tortoise scale, Toumeyella parvicornis, is an insect native to the Nearctic region that is able to infest several Pinus species. It can cause weakening, defoliation and, at high infestation levels, tree death. After its first report in Italy in 2015, [...] Read more.

The pine tortoise scale, Toumeyella parvicornis, is an insect native to the Nearctic region that is able to infest several Pinus species. It can cause weakening, defoliation and, at high infestation levels, tree death. After its first report in Italy in 2015, the pest spread rapidly over the surrounding areas and was reported in France in 2021. Due to the threat that this pest poses to pine trees, the suitability of European Mediterranean basin areas for T. parvicornis at different spatial scales was estimated by constructing species distribution models (SDMs) using bioclimatic variables. Our results showed that several coastal areas of the Mediterranean basin area could be suitable for T. parvicornis. Based on performance assessment, all the SDMs tested provided a good representation of the suitability of European Mediterranean non-native area for T. parvicornis at different spatial scales. In particular, most of the areas with a medium or high level of suitability corresponded to the geographical range of distribution of different Pinus spp. in Europe. Predicting the suitability of European Mediterranean areas for T. parvicornis provides a fundamental tool for early detection and management of the spread of this pest in Europe. Full article

(This article belongs to the Section Insect Pest and Vector Management)

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15 pages, 2700 KiB

Open AccessEditor’s ChoiceArticle

Insulin-like Peptides of the Western Flower Thrips Frankliniella occidentalis and Their Mediation of Immature Development

by Chul-Young Kim and Yong-Gyun Kim

Insects 2023, 14(1), 47; https://doi.org/10.3390/insects14010047 - 3 Jan 2023

Cited by 7 | Viewed by 2388

Abstract

Insulin-like peptides (ILPs) mediate various physiological processes in insects. Specifically, ILP expression is required for immature development in different insects. The western flower thrips, Frankliniella occidentalis, is polyphagous, but its occurrence and population density vary among different hosts. This study assesses [...] Read more.

Insulin-like peptides (ILPs) mediate various physiological processes in insects. Specifically, ILP expression is required for immature development in different insects. The western flower thrips, Frankliniella occidentalis, is polyphagous, but its occurrence and population density vary among different hosts. This study assesses the developmental variations in the thrips through quantitative analysis of their ILP expressions. Two types of ILPs (Fo-ILP1 and Fo-ILP2) were identified from the genome of F. occidentalis, and both ILPs were predicted to have the characteristics of signal peptides and B-C-A chains linked by cysteines. A phylogenetic analysis indicates that these two ILPs in the thrips are clustered with the ILP1 of Drosophila melanogaster, suggesting their physiological roles in growth. In addition, the two ILP genes were relatively highly expressed at all feeding stages, but their expression was reduced during the nonfeeding prepupal and pupal stages. Furthermore, RNA interference of each ILP expression led to significant developmental retardation. In validating the ILP expression in the thrips’ development, five different varieties of host hot peppers were assessed in a choice test, along with the immature development of F. occidentalis. The expression levels of the two ILP genes were highly correlated with variations in the immature developmental rates of different hot pepper varieties. These suggest that Fo-ILP1 and Fo-ILP2 mediate the immature development of F. occidentalis by sensing different nutritional values of hot peppers. This study is the first report on ILPs in thysanopteran insects. Full article

(This article belongs to the Section Insect Physiology, Reproduction and Development)

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