Journal of Insect Science最新文献

Reticulitermes is a genus of subterranean termites that experienced a rapid radiation during the late Miocene, resulting in a widespread distribution across the Holarctic region. Despite decades of phylogenetic research that has delineated some well-supported lineages, relationships among them remain unresolved. Previous studies based on a handful of mitochondrial or nuclear markers have produced conflicting topologies and failed to robustly resolve deep nodes within the genus, particularly among the East European-West Asian (EE + WA) and Western Europe lineages. More recently, despite improved resolution achieved through mitochondrial phylogenomics, a major limitation in Reticulitermes studies has been the complete absence of mitochondrial genomes for the EE+WA lineage. To address this, we sequenced 6 new mitochondrial genomes from 5 Reticulitermes taxa, including the first representatives of the EE + WA clade, and analyzed them alongside previously published data. Phylogenies were inferred across a range of analytical conditions. All analyses supported the monophyly of Reticulitermes, though the placement of EE + WA varied depending on the data and model. Analysis of the nucleotide dataset recovered EE + WA as sister to all other clades. In contrast, the amino acid dataset found it nested within the genus, placing East Asia as the earliest diverging lineage. Our results underscore the sensitivity of phylogenetic inference to dataset and model choice in the context of Reticulitermes rapid radiation and provide new insights for resolving the evolutionary history of this genus. The inclusion of EE + WA fills a key geographic gap and suggests a complex history of diversification, consistent with either an ancient refugial split in southeastern Europe-Western Asia or an extraordinarily rapid westward expansion.

This study investigates the mechanisms governing the formation and transfer of microbial communities associated with the honey bee (Apis mellifera L.) superorganism, focusing on the interplay between plant, in-hive, and bee environments. By analyzing 16S rRNA sequencing data from multiple public datasets through bioinformatics and statistical modeling, we characterized the structure and transmission pathways of these microbiota. Our analysis reveals that each environment hosts a distinct and specialized microbial community, with significant barriers to free microbial exchange. Alpha and beta-diversity analyses confirmed the uniqueness of the bee gut microbiota and the mixed, intermediate nature of the honey microbiome. Structural equation modeling identified that direct microbial transfer from plants to bees is negligible. Instead, honey serves as an obligate intermediary and selective filter, with microorganisms transitioning from plants to honey before a lower-probability transfer to bees occurs. Furthermore, we identified key bacterial taxa, including Apilactobacillus kunkeei, Acinetobacter, and Pseudomonas, that potentially act as generalists capable of persisting across multiple environments. These findings underscore the possibility of the selective bacterial transfer between hives, which may play roles in both pathogens transfer and maintaining hive microbiome stability.

Stem borers of the genus Sesamia are major pests of cereals in tropical regions. In Iran, Sesamia cretica and Sesamia nonagrioides significantly affect maize and sugarcane, but distinguishing them at the larval stage is difficult due to morphological similarity. In this study, we developed and optimized a rapid, cost-effective multiplex PCR method for simultaneous identification of both species. Primers designed from GenBank sequences yielded specific bands of 367 bp for S. cretica and 438 bp for S. nonagrioides. PCR and sequencing confirmed the specificity of the designed primers, while morphological comparison of larvae and reared adults validated the molecular results. This molecular tool supports integrated pest management by improving identification accuracy, which could help reduce unnecessary pesticide applications.

Integrated pest management programs often use pesticides alongside behavioral tactics, such as mating disruption, to manage pests. Pest management using biotremology, the study of vibrations produced by organisms, is gaining attention but requires substantial knowledge of pests and their environment. Here, we built on previous characterizations of vibrational mating signals in pear psylla to assess if pear psylla (Cacopsylla pyricola Förster) communication behavior can be exploited for pest management. Specifically, we conducted greenhouse experiments to test the efficacy of 3 vibrational playback treatments for mating disruption: (i) control, (ii) white noise, and (iii) male mating signals, using 2 delivery methods: (i) plant substrate and (ii) trellis wire; these 2 methods assessed whether devices attached directly to pear saplings or trellis wire supporting saplings provided similar results. We also conducted experiments in pear orchards to assess effectiveness of vibrational playbacks as trap supplements. In the greenhouse, white noise and male mating signals delivered through plant substrates reduced pear psylla offspring in 1 of 3 experiments, but never when delivered through trellis wires. Sticky traps in orchards supplemented with vibrational signals trapped more adults and females than sticky traps alone. The results of this study suggest that pear psylla vibrational communication may be exploited for pest control and pest monitoring, but variable efficacy among experiments suggests a need for further examination into delivery methods.

Insects are considered valuable sources of alternative therapeutics to counter the growing global challenge of posed by antibacterial resistance. The termite Macrotermes subhyalinus (Rambur) is particularly of great interest as it not only harbors antimicrobial peptides but it is also an important source of nutrients to millions of people in many regions of the world. In this study, we assessed the nutritional profiles and antimicrobial activities of extracts of termites from distinct environments differing in vegetation. Extracts of termites collected from hilly thicket environment displayed high level of antimicrobial activities against Escherichia coli and Staphylococcus aureus compared to that of termites from farmland and grassland. Moreover, termites from the hilly thicket were also rich in nutrient composition. This study demonstrates the potential of termites as alternative candidates for addressing the complex challenge of malnutrition and antibacterial resistance especially in poorer regions of the world such as the sub-Saharan Africa.

Wild bees are decreasing in species diversity and populations due to human impact. The abundance of the western honey bee (Apis mellifera L.) experiences an inverse trend, enhancing competition with wild bees and the probability of microbiome exchange. Addressing this exchange, we studied the gut microbiome composition of wild and honey bees, focusing on patterns indicating honey bee influence. Three solitary wild bee species (large scabious mining bee [Andrena hattorfiana F.], grey-backed mining bee (Andrena vaga Panzer), and European orchard bee [Osmia cornuta Latreille]) as well as bumble bees as representatives of eusocial wild bees (Bombus spp. Latreille) and honey bees were sampled in the Austrian Alps. Subsequent 16S ribosomal DNA sequencing revealed the composition of the bacterial communities. The bee groups differed concerning their bacterial composition, with honey bees having the least variation among individuals and a low number of exclusive bacterial taxa and bumble bees the highest bacterial diversity. High honey bee densities corresponded with lower bacterial diversity in wild bees and a higher bacterial similarity between wild and honey bees. Some bacterial taxa were found for the first time in the studied bee groups. Furthermore, the composition of bacterial communities differed between solitary and social bees. We found the first hints that high honey bee density negatively impacts wild bees through alterations of wild bee microbiomes. Future studies should focus on understanding microbiome transmission mechanisms and their consequences for wild bees. Suggestions on how to consider wild bee fitness are indispensable in halting the biodiversity crisis.

Oxalic acid (OA) is a promising tool for controlling varroa mites (Varroa destructor Anderson and Trueman), a devastating pest of the European honey bee (Apis mellifera L.). Applying OA as a vapor inside honey bee colonies has been gaining popularity among beekeepers. We conducted a 2-year field study to evaluate the effectiveness of OA in controlling Varroa and assess the potential negative impacts of OA on honey bee larval development. Different doses of OA (1, 2, and 4 g in 2021; 3 and 4 g in 2022) were applied once a week over 3 wks in August at Oregon State University's apiary in Corvallis, OR. Each experimental group included 8 honey bee colonies, with control groups receiving no OA. The Varroa levels in colonies treated with 1 g OA (the current label dose in the US) and 2 g OA were not significantly different from each other and the control group. In both years, 4 g OA effectively suppressed the Varroa population growth but also appeared detrimental to the honey bee larval development. Our findings suggest that while the legally permissible dose of 1 g OA per brood chamber in the United States is insufficient for effective Varroa control, higher doses (3 and 4 g) can significantly suppress Varroa population growth but may also increase larval mortality, highlighting a trade-off between Varroa control and colony health.

Nectar thieves may seriously impact pollinator foraging behavior and, ultimately, pollination services in natural and agricultural contexts. Despite strong interest in pollinators and their services, there remain gaps in our knowledge as to how ants influence bee foraging decisions. Here, we characterized ant-bee interactions at shared resources and the subsequent behavioral sequences exhibited by bees. We found that two-thirds of bumble bee (Bombus impatiens Cresson) behaviors at nectar resources involved direct interactions with Argentine ants (Linepithema humile Mayr). Consistent with predictions of interference competition, the number of ants at a shared resource decreased the probability of a bee feeding and increased the likelihood of a bee being bitten. Similarly, getting bitten by an ant decreased the probability that a bee would subsequently feed and increased the likelihood that a bee engaged in aggressive responses, such as gaping mandibles and attacking the ant. Behavioral sequences fell into two clusters: Cluster 1 was characterized by feeding and nonaggressive behaviors, and Cluster 2 was exemplified by strings of aggressive behaviors. Behavioral sequences that included aggression were longer and more diverse than those involving predominately nonaggressive behaviors, demonstrating that aggression (either on the part of the bee or the ant) extended behavioral exchanges and disrupted bumblebee foraging and resource collection. Our study identified that ant abundance and aggressive biting behaviors were strong predictors of subsequent bee actions. Such experiences may contribute to learned avoidance of ants in future encounters, consistent with interference competition theory, and have broader implications for disrupted foraging in social animals.

Ecological studies of pollinators often require long-term and extensive monitoring, posing a significant cost and limitation to research. Traditional sampling methods of observation such as sweep netting and pan trapping provide valuable information on pollinator diversity, but scale poorly when conducting large sampling efforts across space and time. We introduce "buzzdetect," a tool to apply deep learning models to audio data for passive acoustic monitoring of pollinators, and test our accompanying audio classification model. The model is capable of distinguishing the buzzing of insect flight from environmental noise on a second-by-second basis with a sensitivity of 28% and a precision of 95%. As a demonstration of the value of buzzdetect, we apply the tool to recordings from 4 crops and 1 wildflower. The results reveal differences in timing and intensity of foraging that correspond with prior literature: activity peaked earliest for chicory and latest for soybean, while total activity was higher in mustard and soybean than in the other crops.

Thrips parvispinus (Karny) is a tropical thrips species that recently spread across the world. Extensive plant damage caused by T. parvispinus results in serious losses for growers, for this species feeds mostly on young leaves and flowers. Among many host plants, peppers are readily attacked by T. parvispinus across its geographical range. Effective and sustainable control methods for T. parvispinus in pepper production are urgently needed. Among the biocontrol agents available in North America, Orius insidiosus (Say) and Anystis baccarum L. were chosen for this study because both species are known to establish in pepper crops and are able to kill all mobile life stages, including the adults, of other thrips species. We carried out comparative efficacy trials in the laboratory using sweet pepper leaf disks and in the greenhouse using potted sweet peppers. The laboratory trial showed that 1 adult female of O. insidiosus or A. baccarum can kill adult female T. parvispinus at a similar rate, with approximately 21 and 18 thrips out of 40 killed in 24 h, respectively. The greenhouse cage trial showed that releasing either adult female O. insidiosus or adult female A. baccarum at the rate of 1 per 2 plants resulted in successful establishment of the predator population and reduced T. parvispinus population by 80% compared to the untreated control. Further studies are needed to validate this finding in larger scale greenhouse trials without cages, including damage assessment and fruit yield data.