Insects最新文献

This study investigated the population dynamics of Vespa orientalis L. (Hymenoptera: Vespidae) across two consecutive seasons (2023-2024) in selected apiaries, with a focus on nest composition (eggs, larvae, and pupae) and the effectiveness of various bait traps for capturing the species. Monthly monitoring revealed the highest population peaks in October and the lowest in December. Notable inter-seasonal variations in population density were observed across the studied sites. The average number of individuals per nest varied between seasons, reflecting fluctuations in colony development and environmental factors. In 2023, the mean counts of cells, eggs, larvae, and pupae per nest were 30.14, 18.77, 13.33, and 20.88, respectively, while in 2024, they were 10.55, 14.81, 18.02, and 30.43. Among the tested attractants, grape juice proved the most effective, capturing an average of 511.67 hornets, followed by black honey (422.33 hornets), whereas the capturing trap caught only 5 hornets. These findings provide insights into the seasonal activity and reproductive status of V. orientalis and support the development of environmentally friendly capture strategies.

Classical biological control of exotic invasive weeds first took place in India in 1795. Thus far, a total of 174 natural enemies have been imported into India, and out of these, 77 have established themselves in the field. Twelve exotic insect pests and four weeds were successfully controlled with a combination of classical, augmentative, and conservation biological control. Additionally, eight insect pests and one weed were substantially controlled. Augmentative biological control has been adopted as per the needs and availability of resources. Conservation biological control is ubiquitous and has been facilitated by the adoption of integrated pest management. In the past, biological control activities were sporadic; however, since 1977, the Indian Council of Agricultural Research-National Bureau for Agricultural Insect Resources has been regularly implementing classical biological control of invasive agricultural insect pests of economic importance. Unfortunately, the importance given to invasive weeds and insect pests of natural resources has fallen behind in recent years.

Safe overwintering is a challenging issue in rearing management that is inevitably faced by beekeepers in high-latitude regions. Under the combined influence of multiple factors, the overwintering loss rate of Western honey bees has risen continuously, and investigating the molecular mechanisms related to safe overwintering has become key. The Hunchun bee, an Apis mellifera ecotype in Jilin Province, China, exhibits strong overwintering ability during an overwintering period of more than five months. To investigate the molecular mechanisms of its cold resistance, we conducted a comparative transcriptomic analysis between the summer breeding period (July) and different overwintering intervals (November, December, January, and February), and then systematically identified key genes and signaling pathways related to cold resistance. The results showed that the highest number of differentially expressed genes (DEGs) was found between December and July. Compared with July, the upregulated genes in Hunchun bee in December were significantly enriched in several pathways, such as ion transport and neuroactive ligand-receptor interactions, and the downregulated genes were significantly enriched in pathways related to fatty acid metabolism, glutathione metabolism, and the peroxisome. Notably, a total of 378 shared DEGs were obtained from the four comparison groups, and several candidate cold-resistant gene families, such as AFPs, HSPs, C₂H₂-ZFPs, STKs, and LRRCs, were identified among the shared DEGs of the winter season. Additionally, 749 shared DEGs related to protein modification and metabolic process regulation were identified between the four successive overwintering intervals. Four shared genes, including sensory neuron membrane protein 1 (SNMP1), were revealed by pairwise comparison of the four intervals. The above results collectively indicate that the Hunchun bee attenuates winter-induced stress responses during the overwintering process by maintaining osmotic pressure balance, reducing fatty acid metabolism, increasing antioxidant capacity, and synthesizing cold-resistant macromolecular proteins. It was also found that chemical signal perception may serve a role in maintaining the stability of the overwintering bee colony. The key genes and pathways related to cold resistance identified in this study not only provide a basis for explaining the overwintering molecular mechanism for Apis mellifera of Hunchun bee but also offer key data to improve overwintering management strategies for Western honey bees.

Culicoides biting midges are vectors of veterinary and zoonotic pathogens, yet the bacteriome of several species remains unexplored. Culicoides reevesi, a poorly studied species in northern Mexico, represents an opportunity to investigate microbial associations that may influence vector biology. Adults of C. reevesi were analyzed using 16S rRNA amplicon sequencing, followed by functional prediction with PICRUSt2. Heatmaps and pathway summaries were generated to highlight dominant taxa and functions. The bacteriome was dominated by Pseudomonadota, followed by Actinomycetota, Bacillota, and Bacteroidota. Symbiotic taxa such as Asaia and Cardinium were identified alongside potentially pathogenic bacteria, including Escherichia coli, Mycobacterium avium, Vibrio parahaemolyticus, and Enterococcus faecalis. Functional predictions indicated metabolic versatility, with abundant pathways related to aerobic respiration, the TCA cycle, amino acid biosynthesis, and quorum sensing. Despite all samples being collected from the same site and date, apparent differences in bacterial composition were observed across pools, suggesting microhabitat or host-related variability. This study provides the first taxonomic and functional baseline of the C. reevesi bacteriome. The detection of both symbiotic and pathogenic bacteria highlights the dual ecological role of the microbiome in host fitness and pathogen transmission potential. In conclusion, we suggest that these microbial associations influence vector physiology and competence, providing a basis for future microbiome-based control strategies. These findings emphasize the importance of integrating microbiome analyses into entomological surveillance and vector control strategies in endemic regions.

Freshwater ecosystems are among the most vulnerable habitats worldwide, and reliable biodiversity assessment is essential for their conservation. Baiyangdian Lake, the largest freshwater lake in northern China, has undergone severe ecological degradation but is now experiencing recovery through restoration efforts. To provide a molecular basis for monitoring biodiversity, we constructed a COI DNA barcode reference library of aquatic insects from Baiyangdian Lake. From January 2023 to May 2025, systematic sampling across representative habitats yielded 315 high-quality sequences covering 104 species, 74 genera, and 33 families within eight insect orders. Diptera, particularly Chironomidae, showed the highest diversity, followed by Odonata. Phylogenetic analysis using maximum likelihood resolved all orders and families as well-supported monophyletic groups, demonstrating strong congruence with morphological taxonomy. Genetic distance analysis revealed a pronounced barcode gap, with mean intraspecific divergence of 0.46% and nearest-neighbor divergence exceeding 15%, confirming the discriminatory power of COI for species identification. Accumulation curves indicated that genus-level diversity is largely captured, while species-level diversity, especially among Diptera, remains incompletely revealed. This study provides the first comprehensive DNA barcode reference library for Baiyangdian aquatic insects, supporting ecological restoration evaluation, eDNA applications, and regional biodiversity conservation strategies.

Population models offer insights into both theoretical and practical aspects of insect population dynamics. Among the models, stage-structured matrix models are used to describe the population dynamics of insects because the development of insects is by nature stage-structured. Field populations of the pine caterpillar, Dendrolimus spectabilis (Lepidoptera: Lasiocampidae) were monitored in a pine stand located in Dorak-ri, Cheongsan-myeon, Wando-gun, Jeollanam-do, from May 1998 to March 1999, and the pest density was measured as the number of larvae, pupae, or eggs at one-month intervals, excluding the winter season. Life tables and matrix models were constructed based on field observations, and the most vulnerable life stage was identified through sensitivity analysis. The density of the pine caterpillar (number per 1000 cm² branch) was 7.9 on 8 May 1998, and subsequently decreased to 0.5 on 14 March 1999, showing a decreasing trend of caterpillar density. The population growth rate was 0.74, a decreasing trend. The most vulnerable stages were (1) the larvae immediately after hatching and (2) again during overwintering, probably due to indirect mortality caused by humid conditions and activities of natural enemies during winter. Given the significant damage caused by mature larvae in the spring and that the density of the caterpillar after overwintering typically remains stable, forest management requires that the pest density be monitored soon after overwintering to allow decisions about control measures to be taken. Our results showed that a matrix model is useful to describe the population dynamics of the pine caterpillar and to construct suitable management strategies.

Honey bees, as vital pollinators and essential contributors to terrestrial ecosystems, play a critical role in maintaining biodiversity and ecological stability. Beyond their role as pollinators, honey bees are increasingly recognized as bioindicators of environmental health, with their microbiomes reflecting habitat quality, agricultural practices, and broader ecological conditions. This study examines the impact of monoculture and polyculture systems on bee-associated microbiomes, focusing on microbial diversity, composition, and functional roles. Microbial communities from floral surfaces, pollen, nectar, foraging bees, hive matrices, and bioaerosols were analyzed across three agricultural plots: a rape monoculture, a pear monoculture, and a polyculture plot. Using 16S rRNA amplicon sequencing, network co-occurrence analysis, and microbial source tracking, the findings reveal that plant species and cultivation methods significantly shape microbial dynamics (Adonis = 0.67 ***). Floral microbiomes exhibit host specificity (Adonis = 0.73 ***), while the honey bee body surface functions as a microbial hub linking environmental, floral, and hive microbial networks (average degree pear: 21.86; rape: 21.96). The polyculture system improves microbial diversity due to the diversity of nectar plants, enhancing ecosystem connectivity and potentially benefiting honey bee health. These results highlight the ecological importance of optimizing agricultural practices to preserve microbial diversity, enhance honey bee health, and maintain ecological stability.

Fungicides play a critical role in crop protection, yet their potential threats to pollinator remain a concern. This study investigated the sublethal effects of a commercial fungicide, Chunmanchun^® (a suspension-emulsion of 7% propiconazole and 28% carbendazim), on cognitive functions of the honey bee (Apis mellifera). Using the proboscis extension reflex (PER) assay, we evaluated sucrose sensitivity and olfactory learning and memory in workers exposed to the recommended field concentration (PC), along with sublethal (LD₁₀) and semi-lethal (LD₅₀) concentrations. Fungicide exposure significantly reduced sucrose sensitivity across all concentrations tested (0.1%, 1%, and 3%), with the strongest reductions occurring at the LD₁₀ and LD₅₀ levels. While olfactory associative learning was not significantly impaired, memory retention was adversely affected. Bees in the LD₅₀ group showed significantly reduced PER rates at both1 h and 6 h post-training, and LD₁₀ and LD₅₀ groups exhibited significant memory deficits by 1 h and 6 h relative to the control. These results demonstrate that Chunmanchun^® impairs both sucrose responsiveness and olfactory memory in honey bees, which may impair foraging efficiency and ultimately affect colony performance. This study highlights a potential ecological risk posed by this fungicide to pollinators in agricultural environments.

A male specimen of whitefly Pudrica christianottoi Drohojowska et Szwedo, 2024, of subfamily Aleyrodinae, previously known from the sole female specimen from Lower Lusatia succinite, is here described, based on an inclusion from Bitterfeld amber. This fossil is contributing new data to our understanding of morphological disparity, sexual dimorphism, taxonomic diversity and palaeobiogeographic distribution of the whiteflies in the Eocene fossil resins. It is also a contribution to the ongoing discussions on age, similarities, dissimilarities and taphonomic differences among Eocene resins of Europe collectively known as 'Baltic amber'.

Determining the drivers of phenotypic evolution and their role on shaping regional phenotypic diversity is a fundamental aspect of mimicry research. Beetles of the genus Ceroglossus are well known for their rampant color diversity, and species have been shown to exhibit convergence in elytral coloration when in sympatry. Despite solid phylogenetic evidence showing that color convergence is not the result of shared ancestry, more direct evidence of the role of selection on color evolution is lacking. In this study, we used two different, but complementary approaches to test whether selection plays a role in color divergence and whether predators are responsible for its maintenance. We first used molecular data to assess gene flow. Subsequently, we used the sequence data to conduct coalescent simulations and generate expectations for color fixation under the hypothesis of genetic drift. Second, we conducted field experiments to test whether predators exhibited different preferences on mimetic versus non-mimetic phenotypes. Results from the coalescent simulations showed that color fixation exhibited strong deviations from the genetic drift expectation, implying that selection must be responsible for color divergence. Field experiments showed that translocated beetles (into areas where they were not mimics) suffered higher rates of attacks than those beetles that mimicked the locally abundant phenotypes. Thus, our study supports the hypothesis of selection as a driving force of color evolution in Ceroglossus beetles and provides the context that explains and supports previous claims of Müllerian mimicry.