Insects最新文献

Bumblebees are the most important pollinators in alpine areas. Their survival is vulnerable to anthropogenic disturbance. To comprehend the variation in bumblebee diversity in different habitat types and altitudinal gradient, this study carried out transect counting in three distinct habitat types and altitudinal gradient in the source area of the Bailong River between June and September from 2021 to 2022. The result indicates (1) high species richness in bumblebees, as 27 species and 1106 individuals from 9 subgenera were collected. It indicates that the Forest-Grassland ecotone has rich bumblebee diversity. Edge effective and suitable habitats bred rich bumblebees. (2) Species richness and abundance differed between three habitat types: alpine meadows had the highest; shrubs on the forest edge had the second highest; and grasslands had the lowest. (3) The distribution pattern in the altitude of bumblebees shows two peaks. The species richness and abundance of bumblebee are highest in the ranges of 3500-3700 m and 2900-3100 m, while 3100-3500 m is lower than the other altitude ranges, presumably because this range is just a large grassland with overgrazing. (4) The results of redundancy analysis indicate that environmental factors significantly affect the diversity of bumblebees. (5) The conservation measures should mainly focus on alpine meadows, as they are the most important habitat of the bumblebee. Reducing overgrazing in large-scale grasslands is beneficial to bumblebees as well as wildflower plants.

Under the background of global climate change, frequent drought events have significantly impacted plant-insect interaction. This study focuses on Ficus microcarpa, an important landscaping and urban greening tree species in tropical and subtropical regions, and its primary herbivorous pest, Perina nuda, by applying the age-stage, two-sex life table theory to systematically evaluate the effects on the life history traits and population dynamics of P. nuda reared on F. microcarpa subjected to different levels of drought stress. The results demonstrated that reared on drought-stressed F. microcarpa significantly altered multiple life history traits of P. nuda. All drought treatments significantly shortened the larval development period. Under both light and severe drought conditions, adult lifespan was prolonged, the total pre-oviposition period was reduced, fecundity per female increased, and generation time (T) was shortened. However, significant increases in pupal weight, intrinsic rate of increase (r), and finite rate of increase (λ) were observed only under light drought stress. The population prediction results indicate that both light and severe drought stress lead to obviously higher population growth rates and larger population sizes at 200 days compared to the control group. These findings suggest that the population fitness of P. nuda is enhanced under light and severe drought stress, potentially increasing the probability of pest outbreaks. This study provides an important theoretical basis and practical advice on forecasting population dynamics and implementing integrated management strategies for P. nuda in the context of climate change.

Illinoia lambersi is a key aphid pest in Rhododendron cultivation in northwestern Europe, where control measures still heavily rely on chemical insecticides. The present laboratory study assessed the predatory potential of the brown lacewing Micromus angulatus on a mix of late instars and adults of I. lambersi across three temperatures (15, 20, and 25 °C) and compared its performance with that of the commonly used green lacewing Chrysoperla carnea sensu lato. Predation rates were measured for third-instar larvae and adults of M. angulatus and for second- and third-instar larvae of C. carnea. Third instars of M. angulatus were highly effective, killing 30-52 aphids per day, with predation significantly increasing at 25 °C. At 15 °C, M. angulatus third instars performed similarly to C. carnea third instars; at 20 °C, C. carnea exhibited higher predation. In all cases, M. angulatus third instars outperformed C. carnea second instars. Female M. angulatus adults maintained steady predation rates (≈30-40 aphids per day) across temperatures, whereas males were less voracious. These findings highlight the potential of M. angulatus as a predator in both its larval and adult stages for integration into IPM programs targeting in particular early-season I. lambersi outbreaks under cool spring conditions. Further field studies are needed to validate laboratory findings and assess the performance of the predator across different Rhododendron cultivars.

This study presents the first successful laboratory rearing of Eremobelba eharai, with the establishment of a sustainable multigenerational breeding system. We document for the first time its complete morphological ontogeny across all developmental stages (from larva to adult) and characterize its life cycle. We supplement the original adult description with detailed morphological characterization and illustrations of the gnathosomatic structures, including the subcapitulum, palps, and chelicerae. Scanning electron microscopy showed that its surface is covered with a granular cerotegument. Under isolated rearing conditions, this species can complete the entire egg-to-egg developmental cycle. In addition, preliminary behavioral observations during rearing revealed preferences for dark environments, characteristic leg-shaking movements, and gregarious oviposition on active dry yeast particles, with no evidence of cannibalism.

The courtship behavior of moths is closely related to the biosynthesis and release of sex pheromones. To understand the mechanisms of the reproductive behavior of the ghost moth Endoclita davidi, a host insect of Cordyceps xuefeng (Ophiocordyceps xuefengensis), this study examined the courtship behavior and the ultrastructure of the sex pheromone gland of E. davidi. Infrared photography was used to analyze the courtship behavior, while SEM, paraffin tissue sectioning, and TEM were employed to examine the sex pheromone glands on the hind tibia. The courtship behavior of E. davidi occurs during the scotophase, during which males vibrate their wings and unfold the hairpencils located on the hind tibiae to lure the female moths. The hairpencil's surface features regular longitudinal ridges interspersed with multiple circular pits. Multiple small holes were evident on the slightly enlarged areas close to the ends of the hairpencils. These small holes, formed at the base of the circular pits, connect to the internal glandular duct within the hairpencil, which links to the tibia glandular canal. The epidermal layer of the hind tibiae contains numerous glandular canals and dense microvilli. The glandular cells, specialized from dermal cells, contain numerous mitochondria, rough endoplasmic reticulum, clear vesicles of varying sizes, and round lipid droplets. The sex pheromone glands of male E. davidi release pheromones through the hairpencils in the hind tibia. The courtship behavior and ultrastructure of the sex pheromone gland of the male E. davidi provide a basis for further understanding pheromone release and communication mechanisms.

Guizhou Province is located in the karst area of southern China, where rocky desertification is severe, and habitat fragmentation is prominent. Leafhoppers are widely distributed, with over 2000 recognized species found in China. However, the impact of habitat fragmentation in karst areas on the biodiversity of leafhoppers has not been comprehensively explored. Leafhopper specimens were collected in Bijie City, Guizhou Province (a light to moderate karst rocky desertification area) from 2019 to 2022. Using methods such as the generalized linear model (GLM) and redundancy analysis (RDA), this study explored the impacts of habitat fragmentation and environmental factors (plants, soil, climate) on the genus-level and genetic diversity of leafhoppers. When the degree of habitat fragmentation decreased, the genus diversity of leafhoppers increased significantly. The GLM showed that among the characteristics of fragmented habitats, patch area had the greatest impact on the generic richness of leafhoppers. RDA indicated that gene exchange among leafhoppers was more frequent between patches with irregular boundaries, and leafhoppers in patches with small areas and complex boundaries had greater genetic diversity. As phytophagous insects, leafhoppers were mainly affected by host plants and less affected by soil properties. Mitigating habitat fragmentation had a positive impact on the biodiversity of leafhoppers, which emphasizes the necessity of protecting biodiversity by reducing habitat fragmentation in the future.

Chalcidoids (Hymenoptera: Chalcidoidea), the most important natural enemies of parasitoids, serve as a pivotal factor in the regulation and management of pest populations. Microbiotas mediate interactions among plants, herbivores, and natural enemies and shape host immunity, parasitoid development, and gall formation; however, the niche-specific diversity and functions of tritrophic parasitoid-host-gall systems remain unclear. Focusing on leaf galls induced on twisted willow (Salix matsudana f. tortuosa) by the willow-galling sawfly Euura viminalis and on two chalcidoids, Eurytoma aethiops and Aprostocetus sp., we profiled bacterial and fungal microbiomes across plant surfaces, gall lumen, host larval tissues, and parasitoids using HTAS. Fungal diversity peaked on parasitoids but was depleted in the gall lumen and host tissues; bacterial richness showed the opposite trend, peaking in the gall lumen and decreasing on parasitoids. In networks contrasted by kingdom, fungi showed positive interface-hub connectivity (Cladosporium, Alternaria), whereas bacteria showed negative hub-mediated associations (Pseudomonas, Acinetobacter), indicating habitat-specific replacements: exposed niches favored transport, two-component, secretion-motility and energy functions, whereas the gall lumen reduced transport/motility but selectively retained N/S metabolism; and in host tissues, information processing and nitrogen respiration were highlighted. These results inform microbiome-guided parasitoid biocontrol.

The cotton bollworm, Helicoverpa armigera (Hübner), a cosmopolitan agricultural pest, inflicts severe impacts on global agriculture. As a poikilotherm, it was highly susceptible to climate change, yet critical gaps persist in understanding how its sensitivity interacts with climatic shifts-knowledge essential for integrated pest management (IPM). We, therefore, analyzed H. armigera's susceptibility to temperature variations using long-term pest population and meteorological data from Maigaiti and Bachu Counties (southern Xinjiang) and Shawan County (northern Xinjiang). The results showed H. armigera populations increased overall, with reduced interannual fluctuation magnitude. The main meteorological factors influencing the interannual population changes of H. armigera in Maigaiti, Bachu, and Shawan were T_max difference in winter (98.0%), T_min difference in May (80.7%), and T_min difference in July (99.4%), respectively. Higher winter temperature (particularly February) reduced the spring population sizes across all three regions, with only the population in Bachu showing a significant correlation. For annual populations, warmer winter caused a significant decline in Bachu, a marked increase in Maigaiti, and a non-significant rise in Shawan. Summer temperature below 33 °C boosted populations in all regions; above 33 °C, the Maigaiti population declined non-significantly, while the Bachu population dropped significantly. Climate warming advanced the pest's first appearance, delayed its disappearance, and extended its active period, increasing population size-a trend projected to intensify in the future. Maigaiti and Shawan populations were governed by T_max in winter and T_min in July, respectively, whereas the Bachu population was constrained by temperature differences during multiple key growth and development periods throughout the year. These divergent regulatory patterns and climatic responses reflect varying vulnerability levels, providing a theoretical basis for targeted H. armigera control.

Most assessments of sex pheromone-based mating disruption (MD) for codling moth (CM), Cydia pomonella (L.), have not included measurements of female mating. The recent development of a dual-sex lure (CM4K) combining ethyl (E,Z)-2,4-decadienoate, 4,8-dimethyl-1,3,7-nonatriene, pyranoid linalool oxide, and acetic acid has significantly increased the catch of female CM and made it easier to directly assess various MD programs. Samples of wild female CM populations using this lure were collected from 142 orchards, either untreated or treated with one of seven different dispenser systems for CM MD, from 2021 to 2022. The proportion of unmated females ranged from <0.20 to >0.80 with a median of 0.43 in both years. No differences in the mean proportion of unmated females were found between apple and pear. Moth immigration and supplemental insecticide sprays were hypothesized to be key factors affecting the variability within each MD tactic. Mating levels were significantly higher later in the season. More females were unmated in conventional compared with organic orchards. Means for females not mating among the CM MD programs varied over a 0.20 range, except for one. The exception occurred when two MD tactics (aerosol units plus hand-applied dispensers) were accidentally used together, and the proportion of unmated females was significantly higher.

Insect wing base sclerites are crucial to wing function and evolution, yet their diversity beyond order-level comparisons remains poorly understood. We examine variation in wing base sclerites across Vespidae, focusing on the axillary sclerites (1Ax, 2Ax, and 3Ax), the shoulder sclerite, and associated structures. The first axillary sclerite shows distinct regional differentiation and bears a well-sclerotized knob that influences wing articulation. Additionally, 2Ax in Vespidae is a single, triangular structure with three attachment points, distinct from the two-part composition in some other wasps, which facilitates high-frequency wing vibrations. Our findings also highlight variable fusion patterns in 3Ax and its interaction with 2Ax, contributing to wing flexibility. The basiradial bridge, connecting the subcostal and radial veins, reinforces wing stability and articulation. Phylogenetic analysis based on wing-base morphology does not support the monophyly of Vespidae and differs from molecular hypotheses, but it refines previous morphological interpretations. The well-supported subfamily relationships confirm Vespinae as a monophyletic group and reveal a close association among Polistinae, Stenogastrinae, and Eumeninae, as represented by Polistes, Eustenogaster, and Oreumenes, respectively, suggesting evolutionary transitions in social behavior within the family Vespidae. The absence of a fourth axillary sclerite challenges earlier hypotheses, providing new insights into Hymenopteran wing base evolution. Two articulation models are proposed for forewings and hindwings, supported by three-dimensional reconstructions of axillary sclerites, indirect and direct flight muscles, and their attachment sites. These results refine interpretations of wasp wing mechanics, evolution, and morphological diversification across taxa.