Journal of Insect Science最新文献

Honey bees (Apis mellifera L.) are of undeniable value to agriculture. However, increased mortality of honey bees, mostly due to winter losses associated with parasites and pathogens, have put strain on the apiculture industry. Advancing our knowledge of honey bee viruses and their interactions within the colony environment is vital in mitigating their effect on honey bee health. Our study examined virus sequences detected on beeswax sampled from empty colonies which died during the previous winter. Based on a cage study using virus-containing bees, we confirmed that the introduction of BQCV sequences to wax foundation was possible through workers walking on, and contacting, comb surfaces (worker traffic). Furthermore, we found that BQCV may aerosolize within an incubator to contaminate wax at detectable levels among independent cages. A second cage study explored the potential effects of virus aerosolization on transmission between groups of adult worker bees within cages, having no direct contact. This experiment did not support aerosol transmission between groups of bees in confined spaces. Further work on waxborne virus transmission within colony environments, and potential effects of aerosolization under a wider array of conditions, is crucial to broadening our knowledge of honey bee virus transmission. Our work also highlights potential dangers for beekeepers re-using equipment from dead colonies.

Identifying a DNA extraction method that yields high quantity and quality DNA is a crucial component of molecular ecological studies; and the best suited method can vary greatly depending on research priorities. Here, we propose a nondestructive extraction method for insect museum vouchers aimed at analyzing gut-associated microbiomes. The leafhopper Euscelidius variegatus (Kirschbaum) (Hemiptera: Cicadellidae) associated with the bacterial plant pathogen Flavescence dorée phytoplasma, a member of the genus 'Candidatus Phytoplasma' (Mollicutes: Acholeplasmataceae), was used as an experimental model. We developed and refined a resin-based DNA extraction protocol by testing the effects of prelysis bleaching and postlysis proteinase K inactivation on DNA quality and yield. We found that bleaching did not compromise the integrity of insect and associated bacterial DNA and that excluding the inactivation of proteinase K did not interfere with quantitative polymerase chain reaction analysis. Based on our findings, we recommend a DNA extraction protocol for insect voucher specimens and associated microbiomes that includes a prelysis bleaching step to chemically degrade external contaminants without proteinase K inactivation, thereby reducing processing time. Our refined protocol resulted in a high DNA yield, which we successfully analyzed using quantitative polymerase chain reaction analysis and other downstream molecular applications, including targeted high-throughput sequencing.

Ephestia elutella is a globally distributed storage pest, and its growth and development are regulated by juvenile hormones. To investigate the molecular mechanisms underlying the response of E. elutella larvae to the juvenile hormone analog s-methoprene, this study examined the effects of s-methoprene on the growth and development of E. elutella, explored the response of E. elutella to s-methoprene exposure by transcriptomic analysis, and confirmed its hub genes by RT-qPCR experiments. Larval mortality of E. elutella increased and adult emergence decreased with increasing exposure durations and doses of s-methoprene. After exposure at 5 × 10⁻⁵ mg/cm² of s-methoprene for 4 wk, a few of larvae pupated, but failed to emerge into adults, while at 50 × 10⁻⁵ mg/cm² for 4 wk, larvae were completely unable to pupate. Transcriptomic analysis identified 2,569 and 6,719 differentially expressed genes in the EE0 vs. EE5 and EE0 vs. EE50, respectively. Weighted Gene Co-expression Network Analysis identified 5 modules, with the yellow module most relevant to EE5. The genes in the yellow module were significantly enriched in biological processes. The Cluster-6182.18691, Cluster-6182.8343, Cluster-6182.28346, and Cluster-6182.21392 were hub genes in the yellow module. s-Methoprene directly or indirectly inhibited the growth and development of E. elutella larvae by affecting critical biological processes, such as hormonal regulation, etc. RT-qPCR validation confirmed the reliability of the transcriptomic data. This study provides important foundational data and theoretical insights into the molecular mechanisms of E. elutella in response to s-methoprene.

Crickets present a sustainable protein alternative with a lower ecological footprint compared to traditional animal proteins. This research aimed to investigate the effect of dietary energy density on feed intake, growth, and body composition in house crickets (Acheta domesticus L., Orthoptera: Gryllidae) up to 45 d after hatching. The study consisted of 2 phases (7 to 20 and 21 to 45 d of age), with house crickets randomly assigned to 5 dietary treatments, each with six replicates. Dietary energy levels ranged from 3,819 to 4,265 kcal gross energy (GE)/kg in phase 1 and from 3,978 to 4,405 kcal GE/kg in phase 2. As dietary energy density increased, feed intake linearly decreased, while body mass linearly increased. In phase 1, protein retention increased from 72.1% to 85.5% as GE increased from 3,819 to 4,265 kcal /kg. Similarly, in phase 2, protein retention increased from 53.3% to 59.3% as GE increased from 3,978 to 4,379 kcal/kg. Correspondingly, the feed conversion ratio (FCR) improved with increasing dietary GE values. Broken-line analysis revealed the lowest FCR at 4,158 and 4,382 kcal GE/kg feed for house crickets from 7 to 20 and 21 to 45 d after hatching, respectively. These findings confirm the relevance of energy density in achieving optimal growth performance and provide valuable insights for formulating nutritious cricket diets. However, caution is warranted when extrapolating these results, as diets were formulated using GE instead of metabolizable energy (ME). Future studies should determine cricket-specific ME values to fine-tune dietary energy density.

Introduction and spread of nonindigenous species present a formidable threat to forest health. The emerald ash borer (EAB), Agrilus planipennis, is an East Asian-origin insect that has devastated ash (Fraxinus spp.) trees across the United States and parts of Canada since 2002. Proactive surveillance using high-performing predictive models could aid in mitigating pest risk. Predictor variables and modeling methods are important considerations in such analysis. Therefore, we assessed whether relevant single predictors, a combination of predictors grouped under a certain driver category, or multiple key predictors comprising several drivers, alter the goodness-of-fit of logistic regression models to EAB occurrence data (2002 to 2018) from Canada. The predictors used in models included spatial, topographic/positional, transport pathways/human hotspots, host-related factors, and climate-related variables. Using predictors from the best candidate logistic regression model, we tested the performance of 7 different model types including an ensemble model. Our findings showed that predictors from a wide range of drivers better characterized EAB occurrences than single predictors or a combination of predictors from any given driver category. In multi-model comparisons, random forest outperformed all other models, including the ensemble model. Elevation, infestation pressure, accumulated degree-days (>10 °C), and human population density were important predictors of EAB presence. Random forest and ensemble model forecasts for the city of Edmonton, Alberta, Canada, indicated an area of potential concern for EAB. Our research strongly underscores the utility of comparative multi-model approaches in invasive risk assessments that could have important implications for pest surveillance and management.

In order to explore the impact of insect density on the edge effect of Bactrocera minax (Diptera: Tephritidae) adult distribution in orange orchards, traps were set up in orchards with maggot infestation rates of 2%, 4%, and 20% to attract adults. The study compared differences in distribution between the side with noncitrus trees and the side farther away from them. The results showed that at lower insect densities (2% and 4% maggot infestation rates), the proportion of insect trap sites and the number of insects per trap on the side of the orchard adjacent to the trees were significantly higher than that on the side away from the noncitrus trees, additionally, the proportion of adults captured 10 to 20 m away from the side of noncitrus trees was also significantly higher than at other distances. However, at higher insect density (20% maggot infestation rates), there were no significant differences in the proportion of insect traps or the number of insects per trap between the adjacent and distant sides of the trees. Similarly, there were no significant differences in the proportion of adults captured at distances of 10, 20, 30, and 40 m away from the side of noncitrus trees in the orchard. In summary, at low insect density, B. minax adults exhibit a strong edge effect, concentrating on the side of the orchard with noncitrus trees, whereas at high insect density, they are evenly distributed throughout the orchard.

Concerns about the impacts of introduced honey bees (Apis mellifera L.) on native insects and pollination services are prevalent. These impacts may be more pronounced on urban greenspaces, yet research on the use of abundant winter-flowering plants, such as Acacia spp. and Grevillea spp., in subtropical ecosystems is limited. Our study investigated the seasonal use of floral resources by honey bees and native hover flies (Melangyna indet.) in urban greenspaces of varying urbanization levels in Sydney, Australia. We found both insect groups use similar plants, with honey bees having a higher number of interactions with plants in general, but Melangyna interacting with more plant species during some seasons. Particularly in autumn and winter, when native plants flower, Melangyna had more interactions and visited more plant species than honey bees. The overlap in floral resources used by both was higher than expected in various urbanization levels during spring and autumn. This suggests that Melangyna may play a significant role in pollination during autumn and winter, especially in highly urbanized sites. The observed differences in floral resource utilization and seasonal variations indicate that the potential effects of introduced A. mellifera on native pollinators like Melangyna may be difficult to quantify given the high number of variables and complexity of the system. Our findings underscore the importance of considering seasonal patterns and multispecies interactions in studies on the impact of introduced species on native biodiversity.

Adult house flies (Musca domestica L.) are often a major pest at livestock facilities, where oviposition occurs on decomposing organic matter, such as manure. Some potential foods that adult house flies might consume on dairy farms were examined. Relative to when they were given water alone, survival of males and females was greater when they were given water along with liquid whole milk, formulated calf feed, or corn silage, or finely milled sorghum or soy, or buckwheat inflorescences. However, survival was significantly lower with these foods than with sucrose, although not significantly so for males with milk. There was little to no survival advantage when flies were given water along with milled hominy, wet spent brewers grain, or manure than with water alone. Both males and females spent significant time with their labellum in contact with corn silage, dandelion inflorescences, and buckwheat inflorescences, but little time with their labellum contacting manure or white clover inflorescences. Egg production was not increased by access to water along with buckwheat inflorescences or corn silage relative to sucrose; but egg production was increased by access to liquid whole milk. Reaching mature vitellogenesis stages was improved by prior exposure to water and sucrose solution along with a mixture of dry sucrose, milk, and yolk, or along with calf manure or formulated calf feed, but not with milled soy, sorghum, or hominy, or with wet spent brewers grain or citrus pellets. The diet including sucrose-milk-yolk resulted in the most females reaching mature vitellogenesis stages.

Insects are declining in abundance and species richness, globally. This has broad implications for the ecology of our planet, many of which we are only beginning to understand. Comprehensive, large-scale efforts are urgently needed to quantify and mitigate insect biodiversity loss. Because there is broad interest in this topic from a range of scientists, policymakers, and the general public, we posit that such endeavors will be most effective with precise and standardized terms. The Entomological Society of America is the world's largest association of professional entomologists and is ideally positioned to lead the way on this front. We provide here a glossary of definitions for biodiversity loss terminology. This can be used to enhance and clarify communication among entomologists and others with an interest in addressing the multiple overlapping research, policy, and outreach challenges surrounding this urgent issue.

The house fly, Musca domestica L., is a vector of pathogens. When sanitation measures fail to control fly populations, pesticides are often used. Fungal biopesticides have been suggested as another tool in fly control. Our study investigated whether inhibitors of eicosanoid biosynthesis (EBI), and presumably of immunity, combined with the fungal biopesticide BotaniGard ES is a feasible option for a new biopesticide formulation. The EBIs tested were dexamethasone, naproxen, and esculetin. An insecticide-susceptible and an insecticide-resistant house fly strain were tested. Compared to a control sugar cube with no EBI and no BotaniGard ES, both strains spent a shorter duration at sugar cubes with fungus alone and with fungus combined with naproxen; flies from the susceptible strain spent a shorter duration at cubes with fungus combined with dexamethasone; and flies from the resistant strain spent a shorter duration at cubes with fungus combined with esculetin. Both strains, whether exposed to fungus, fungus with dexamethasone, or fungus with naproxen, had higher mortality risk compared to a control. With or without injection of an EBI, immersion in a fungal solution increased mortality. However, with CAR21 flies, mortality was greater with the naproxen injection than with dexamethasone- or esculetin injection with the fungal immersion. Due to no greater mortality for both strains for all EBI and BotaniGard ES combinations compared to BotaniGard ES alone, it is not recommended that dexamethasone, esculetin, or naproxen be used in conjunction with BotaniGard ES for house fly control.