Search Results (8)

In many practical scientific studies, two-way analysis of variance (ANOVA) and linear response surface methods are used for determining whether two or more similar compounds (substances, agents, or drugs) interact synergistically, antagonistically or independently. These models are often found lacking both in the means to assess interaction and with sufficient power. Using ten judiciously chosen illustrations (spanning fields as diverse as aquatic and environmental toxicology, botany, entomology, oncology, pharmacology, and virology), this paper introduces, explores, quantifies, illustrates, interprets, and extends several cutting-edge nonlinear assessment models and methods for measuring and describing interaction. Developed and used here are the Finney and Separate Ray models and extensions, a new cut line approach useful for so-called web designs, and extensions to more than two substances. As noted in the provided examples, the Finney model and extensions have the advantage of characterizing nonlinear interaction in a single measure, whereas the Separate Ray model extension is required when nonlinear interaction requires more than a single parameter for interaction assessment. The interaction results of the ten illustrations—of which antagonism is observed in four examples, synergy in five examples, and mixed results in one example—are summarized below. A discussion is also provided of efficient experimental design strategies as an aid to the practitioner and their future scientific studies. Full article

Rice fields are one of the most important and extensive agro-ecosystems in the world. Italy is a major non-Asian rice producer, with a significant proportion of its yield originating from a vast area within the Po Valley, a region nourished by the waters of the Alps. While the biodiversity of these rice fields has been extensively documented for certain faunal groups, such as birds, there remains a paucity of research on the biodiversity of aquatic insects. A further challenge is the limited dissemination of findings, which have been primarily published in “gray” literature (local journals, newsletters and similar). Moreover, rice fields are of particular significance in the field of invasion biology, given their role in the arrival and spread of alien species. While the efficacy of rice fields as a substitute for the now-disappeared lowland natural environments is well documented, it is equally evident that traditional rice-growing techniques can require an unsustainable use of water resources, which threatens the biodiversity of the surrounding lotic systems. Here, we summarize and review multiple sources of entomological information from Italian rice fields, analyzing both publications in ISI journals and papers published in local journals (gray literature). In the near future, strategies that reduce the demand for irrigation, promote the cultivation of drought-tolerant crops, and utilize precision farming techniques will be implemented. The challenge will be balancing the need to reduce water withdrawal from rivers with the maintenance of wetlands where possible to support this pivotal component of regional biodiversity. Full article

The diversity and distribution of mosquitoes from Sonora, Mexico, was documented through entomologic surveys conducted in the four physiographic regions and sub-regions of Sonora: the Sonoran Plain, the Sierra Madre Occidental, the Northern Mountains and Plains, and the Pacific Coastal Plain. Immature stages were collected from aquatic habitats, while adult mosquitoes were collected using Shannon traps, resting in vegetation, and by human landing collections. Overall, 11,316 specimens, which comprised 493 larvae, 224 larval exuviae, 400 pupal exuviae, 33 pupae, 4552 females, 5607 males, and seven male genitalia, were identified. Two subfamilies: Anophelinae and Culicinae, seven tribes, 10 genera, 23 subgenera, and 56 species are reported below. Of these, one tribe, one genus, five subgenera, and 15 species were recorded for the first time in Sonora. Two species, Aedes deserticola Zavortink and Toxorhynchites septentrionalis (Dyar and Knab), are the first recordings of their kind nationwide. Toxorhynchites septentrionalis was also barcoded with the cytochrome oxidase subunit 1 (COI) gene. The presence of Psorophora columbiae (Dyar and Knab) is confirmed in Mexico. Taxonomic notes, new geographic distribution limits of mosquitoes in Sonora, and information regarding their importance as disease vectors are provided. By adding Ae. deserticola and Tx. septentrionalis and confirming Ps. columbiae in Mexico, there are currently 251 mosquito species in the Country. Full article

The aquatic bug family Naucoridae (Hemiptera: Heteroptera: Nepomorpha) is currently represented in Brazil by 68 species. Although the diversity of the family has been the target of several recent studies, large areas of the country are still unexplored and several species that have been deposited in entomological collections are waiting for a formal description. Aiming to fill these knowledge gaps, a series of expeditions were carried out in six states of eastern Brazil between 2018 and 2023: Alagoas, Bahia, Ceará, Espírito Santo, Pernambuco, and Sergipe. The fieldwork targeted protected areas, but surrounding regions were also explored. The material obtained, in addition to specimens previously deposited in a national entomological collection, revealed the existence of Australambrysus margaritifer Jordão, Santos and Moreira, a new species herein described, and new records for other 11 species and two subspecies belonging to the genera Carvalhoiella De Carlo, 1963, Limnocoris Stål, 1876, Maculambrysus Reynoso-Velasco and Sites 2021, and Pelocoris Stål, 1876. Full article

Two species of black flies (Simuliidae) in Thailand, Simulium chumpornense Takaoka and Kuvangkadilok, 2000, and S. khelangense Takaoka, Srisuka & Saeung, 2022, are potent vectors of avian blood protozoa of the genera Leucocytozoon and Trypanosoma and are pests of domestic avian species. Although the adults are abundant throughout Thailand, information on their breeding habitats is limited, and the immature stages of S. khelangense are unknown. We collected the larvae and pupae of S. khelangense from the Mekong River, the first-ever record of Simuliidae from this large continental river. Mitochondrial cytochrome c oxidase I and internal transcribed spacer 2 were used to associate the larvae and pupae with known adults. Both genetic markers strongly supported their identity as S. khelangense. The larvae and pupa of S. khelangense are described. The pupal gill filaments, larval abdominal protuberances, and setae distinguish this species from other members of the S. varicorne species group. The immature stages of S. chumpornense inhabit a wide variety of flowing waters, from small streams (3 m wide) to enormous continental rivers (400 m wide); thus, S. chumpornense is a habitat generalist. In contrast, S. khelangense was found only in the large Mekong River and is, therefore, a habitat specialist. Both species can exploit their principal habitats and produce abundant adult populations. Full article

For a better understanding of the transmission cycles of mosquito-borne diseases, it is essential to explore the species composition and population dynamics, mainly during their peak abundance period. These investigations do not normally include peri-urban areas, despite their significant epidemiological interest. To address these gaps, an entomological survey was carried out in 2016 and 2017 in three aquatic ecosystems located on the outskirts of the city of Logroño, in northern Spain: the Iregua River and La Grajera (La Rioja) and Las Cañas Reservoirs (Navarra). Mosquitoes were captured using BG-Sentinel traps baited with CO₂ and BG-lure, as well as through the human landing collection method. In total, 6793 mosquito specimens were captured, representing 24 taxa within six genera. A specific PCR based on the ITS2 gene was used to differentiate members of the Anopheles claviger complex, and all individuals were identified as An. claviger sensu stricto. La Grajera had the most diverse culicid fauna, with 19 taxa, followed by Las Cañas (n = 15) and the Iregua River (n = 13). The composition and abundance of Culicidae varied across the aquatic ecosystem. We observed that the different hydrological management practices of each environment could play a key role in determining the abundance of mosquito genera. The overall risk of mosquito bites in the study area is expected to be relatively low and will depend on the freshwater ecosystem and the time of year. Full article

Forensic entomology includes the analysis of organisms colonizing various parts of the body in order to determine the circumstances of an incident, mainly the time, place, and cause of death. The presence of insects and other arthropods on carcasses can be a source of knowledge for the judicial system. However, this type of research (on submerged bodies) is less published. The aim of our study was to analyse the qualitative and quantitative structure of macroinvertebrates colonizing potential evidence in an upland river. The experimental research involved an eight-week exposure to articles of clothing made of different materials: natural materials (bottom sediments with plants from a river), synthetic (socks), and cotton (t-shirts). Control samples of water after 2, 4, 6, and 8 weeks were taken from experiment locations in the River Bystrzyca with a tube apparatus and hand net. The results indicated that the abundance of organisms on a given substrate depended on the period of development of invertebrate macrofauna and the time of exposure of the substrates. The abundance of aquatic macrofauna on the exposed items increased in direct proportion to the duration of the experiment, which may indicate the adaptability of these organisms to new habitat conditions. Among the taxonomic groups used in forensic entomology, Diptera, Coleoptera, and Odonata were the most abundant. The remaining taxa (including Heteroptera), though not widely used in judicial proceedings, can also provide valuable information about the circumstances of an incident. Full article

The effective management of mosquito vectors is a timely challenge for medical and veterinary entomology. In this study, we evaluated the acoustic Larvasonic device to control young instars of the mosquito Aedes aegypti in diverse freshwater environments. Under laboratory conditions, we investigated the effect of exposure time and distance from the transducer on the mortality of larvae and pupae of Ae. aegypti. Furthermore, we evaluated the effectiveness of the ultrasound window of the electromagnetic spectrum under different field conditions. Results showed that first and second instar larvae were more sensitive to the frequency range of 18–30 kHz of the Larvasonic device. Ultrasonic waves applied for 180 s at a frequency from 18 to 30 kHz caused 100% larval mortality at a distance of 60 cm from the transducer. No mortality was observed in the non-target copepod Megacyclops formosanus. The exposure to the soundwaves produced by the acoustic larvicidal device over different distances effectively damaged Ae. aegypti through destruction of the larval dorsal tracheal trunk, thorax and abdomen. Overall, results indicated that the Larvasonic device tested can provide an alternative tool to reduce young instar populations of Ae. aegypti, without any effects on non-target aquatic invertebrates like copepods. It turned out to be a useful device for mosquito biocontrol. This technology has a relevant potential to fight the spread of mosquito-borne diseases. Full article