Bulletin of Entomological Research最新文献

Global warming has driven changes in the biology and fitness of organisms that need to adapt to temperatures outside of their optimal range to survive. This study investigated aspects of reproduction and survival of the lady beetle Tenuisvalvae notata (Mulsant) (Coleoptera: Coccinellidae) subjected to temperatures that varied from its optimal (28°C) to a gradual decrease (12, 14, 16, and 18°C) and increase (32, 34, 35, and 36°C) over time at a rate of 1°C/day. Fertility, fecundity, oviposition period, and survival were determined. There was a significant reduction in fertility and fecundity at temperatures below 18°C and above 34°C, whereas survival was reduced only above 34°C. Additionally, we evaluated that fecundity was the lowest when females were kept at low temperature, and when males were kept under high temperature. Therefore, if the T. notata remained for a long period under exposure to temperatures outside the ideal range, then the species could present different reproductive responses for each sex to high and low temperatures. This factor must be considered when releasing natural enemies into an area to understand the effect of temperature on the decline of a local population a few generations after release.

As global warming increases with the frequency of extreme weather, the distribution of species is inevitably affected. Among them, highly damaging invasive species are of particular concern. Being able to effectively predict the geographic distribution of invasive species and future distribution trends is a key entry point for their control. Opisina arenosella Walker is an invasive species, and its ability to live on the backs of foliage and generate canals to hide adds to the difficulty of control. In this paper, the current and future distributions of O. arenosella under three typical emission scenarios in 2050 and 2090 are projected based on the MaxEnt model combining 19 bioclimatic variables. Filter through the variables to find the four key environment variables: BIO 1, BIO 6, BIO 11 and BIO 4. The results show that O. arenosella is distributed only in the eight provinces of Tibet, Yunnan, Fujian, Guangxi, Taiwan, Guangdong, Hong Kong and Hainan in the southeastern region. Its high suitability area is concentrated in Taiwan and Hainan. In the long run, highly suitable areas will continue to increase in size, while moderately suitable areas and poorly suitable areas will decrease to varying degrees. This paper aims to provide theoretical references for the control of O. arenosella.

The egg parasitoid Anastatus japonicus is a key natural enemy in the biological control of various agricultural and forestry pests. It is particularly used against the brown marmorated stink bug Halyomorpha halys and the emerging defoliator pest Caligula japonica in East Asia. It has been proved that the eggs of Antheraea pernyi can be used as a factitious host for the mass production of A. japonicus. This study systematically documented the parasitic behaviour and developmental morphology exhibited by A. japonicus on the eggs of A. pernyi. The parasitic behaviour of A. japonicus encompassed ten steps including searching, antennation, locating, digging, probing, detecting, oviposition, host-feeding, grooming, and resting. Oviposition, in particular, was observed to occur in three stages, with the parasitoids releasing eggs during the second stage when the body remained relatively static. Among all the steps of parasitic behaviour, probing accounted for the longest time, constituting 33.1% of the whole time. It was followed by digging (19.3%), oviposition (18.5%), antennation (9.6%), detecting (7.4%), and the remaining steps, each occupying less than 5.0% of the total event time. The pre-emergence of adult A. japonicus involves four stages: egg (0 to 2nd day), larva (3rd to 9th day), pre-pupa (10th to 13th day), pupa (14th to 22nd day), and subsequent development into an adult. Typically, it takes 25.60 ± 0.30 days to develop from an egg to an adult at 25℃. This information increases the understanding of the biology of A. japonicus and may provide a reference for optimising reproductive devices.

Anthropogenic-mediated climate change is expected to negatively affect pest management in agriculture. Hence, we investigated the oviposition, immature mortality, and developmental processes of Spodoptera species (Spodoptera exigua (Hübner) and Spodoptera litura (Fabricius)) under different temperatures (20, 25, and 30°C) and relative humidity (RH) (30-35, 50-55, 70-75, and 90-95%) conditions. For fecundity, mouths of each Spodoptera species were released into a rectangular box whose inner walls were covered with a sheet of white paper for each combination of temperature and RH. The mouths were kept inside the box to deposit eggs for 72 h. Temperature and RH significantly affected the fecundity, with the maximum number of eggs laid in 70-75% at 30°C. The highest egg and larval mortalities were recorded in 30-35 and 90-95% RH, respectively. Temperature and RH greatly affected the developmental period (egg-adult) and adult emergence rate. The rapid development was recorded in 70-75% RH at 30°C. Higher number of adults was found with an increase in temperature and RH. Adult longevity was significantly higher in 70-75% RH at 20°C. Based on the present study's findings, temperature and RH had an individual apparent effect on the developmental processes of Spodoptera species instead of an interactive effect. Therefore, there is need for an in-depth study of the influence of several climatic factors, including CO₂, on the developmental modality and demographic changes of Spodoptera species to assess the impacts of climatic components and the sustainable development of management strategies.

The diversity and health of insects that feed on plants are closely related to their mutualistic symbionts and host plants. These symbiotic partners significantly influence various metabolic activities in these insects. However, the symbiotic bacterial community of toxic plant feeders still needs further characterisation. This study aims to unravel bacterial communities associated with the different species of insect representing three insect orders: Thysanoptera, Hemiptera, and Lepidoptera, along with their predicted functional role, which exclusively feeds on latex-rich plant species Ficus microcarpa. By using 16S rRNA gene high-throughput sequencing, the analysis was able to define the major alignment of the bacterial population, primarily comprising Proteobacteria, Firmicutes, Bacteroidota, Actinobacteriota, and Acidobacteriota. Significant differences in symbiotic organisms between three insect groups were discovered by the study: hemipterans had Burkholderia and Buchnera, and lepidopterans had Acinetobacter. At the same time, Pseudomonas was detected in high abundance in both lepidopteran and thysanopteran insects. Furthermore, these symbionts exhibit consistent core functions, potentially explaining how different insects can consume the same host plant. The identified core functions of symbionts open avenues for innovative approaches in utilising these relationships to develop environment-friendly solutions for pest control, with broader implications for agriculture and environmental conservation.

Deformed wing virus (DWV), which is an important honey bee virus transmitted by Varroa destructor (V. destructor), causes colony losses in honey bee colonies. This study aimed to investigate the prevalence and genetic diversity of DWV in honey bees in Türkiye and to determine the role of V. destructor in the transmission of the genetic variants of DWV. Honey bee samples were collected from 62 apiaries, by simple random sampling, during March 2022 and April 2023. The presence of V. destructor in collected bee samples was examined using a stereo microscope. Real-time RT-PCR was used for the detection of DWV-A and DWV-B (Varroa destructor virus-1 (VDV-1)) viruses. Genetic characterisation of the positive samples was conducted by sequencing polyprotein genomic region. Considering the V. destructor infestation rate of 3% as relevant, out of the 62 apiaries examined, 17 (27.4%) were positive. However, DWV-A and VDV-1 specific RNA was not detected in V. destructor samples. VDV-1 specific RNA was detected in 6.5% (4/62) of the apiaries, whereas DWV-A was not detected in the sampled apiaries. Phylogenetic analysis showed that isolates detected in this study were located in a separate cluster from previously characterised DWV-A and VDV-1 isolates. According to RDP4 and GARD analyses, DWV-VDV-1 recombination breakpoints were detected in field isolates. To the best our knowledge, this is the first report of the presence of VDV-1-DWV recombinants in Türkiye. Further studies are needed to determine the impact of VDV-1-DWV recombinants and their virological and antigenic properties.

NADPH-cytochrome P450 reductase (CPR) is crucial for the detoxification process catalysed by cytochrome P450, which targets various exogenous xenobiotics, as well as pesticides. In our research, we successfully obtained the complete cDNA sequence of Apolygus lucorum's CPR (AlCPR) using reverse transcription PCR along with rapid amplification of cDNA ends technology. Bioinformatics analysis exhibited that the inferred amino acid sequence of AlCPR is characteristic of standard CPRs, featuring an N-terminal membrane anchor and three conserved FMN, FAD and NADP binding sites. Phylogenetic result revealed that AlCPR was positioned within the Hemiptera cluster, showing a close evolutionary relationship with the CPR of Cimex lectularius. The real-time quantitative PCR results demonstrated widespread expression of AlCPR across various life stages and tissues of A. lucorum, with the most prominent expression in adults and the abdominal region. Injecting double-stranded RNA of AlCPR only significantly increased the lambda-cyhalothrin susceptibility in lambda-cyhalothrin-resistant strain rather than the susceptible strain. These findings suggest a potential link between AlCPR and the P450-dependent defence mechanism against lambda-cyhalothrin in A. lucorum.

Plant–soil interactions have bottom–up and top–down effects within a plant community. Heavy metal pollution can change plant–soil interactions, directly influence bottom–up effects and indirectly affect herbivores within the community. In turn, herbivores can affect plant–soil interactions through top–down effects. However, the combined effects of heavy metals and herbivores on soil enzymes, plants and herbivores have rarely been reported. Therefore, the effects of lead (Pb), Spodoptera litura and their combined effects on soil enzyme activities, pakchoi nutrition, defence compounds and S. litura fitness were examined here. Results showed that Pb, S. litura and their combined effects significantly affected soil enzymes, pakchoi and S. litura. Specifically, exposure to double stress (Pb and S. litura) decreased soil urease, phosphatase and sucrase activities compared with controls. Furthermore, the soluble protein and sugar contents of pakchoi decreased, and the trypsin inhibitor content and antioxidant enzyme activity increased. Finally, the S. litura development period was extended, and survival, emergence rates and body weight decreased after exposure to double stress. The combined stress of Pb and S. litura significantly decreased soil enzyme activities. Heavy metal accumulation in plants may create a superposition or synergistic effect with heavy metal-mediated plant chemical defence, further suppressing herbivore development. Pb, S. litura and their combined effects inhibited soil enzyme activities, improved pakchoi resistance and reduced S. litura development. The results reveal details of soil–plant–herbivore interactions and provide a reference for crop pest control management in the presence of heavy metal pollution.

Confronting environments with low relative humidity is one of the main challenges faced by insects with expanding distribution ranges. Anastrepha ludens (the Mexican fruit fly) has evolved to cope with the variable conditions encountered during its lifetime, which allows it to colonise a wide range of environments. However, our understanding of the mechanisms underpinning the ability of this species to confront environments with low relative humidity is incomplete. In this sense, omic approaches such as transcriptomics can be helpful for advancing our knowledge on how this species copes with desiccation stress. Considering this, in this study, we performed transcriptomic analyses to compare the molecular responses of laboratory-reared A. ludens exposed and unexposed to desiccation. Data from the transcriptome analyses indicated that the responses to desiccation are shared by both sexes. We identified the up-regulation of transcripts encoding proteins involved in lipid metabolism and membrane remodelling, as well as proteases and cuticular proteins. Our results provide a framework for understanding the response to desiccation stress in one of the most invasive fruit fly species in the world.

Changes in the distribution of species due to global climate change have a critically significant impact on the increase in the spread of invasive species. An in-depth study of the distribution patterns of invasive species and the factors influencing them can help to better predict and combat invasive alien species. Rhynchophorus ferrugineus Olivier is an invasive species that primarily harms plants of Trachycarpus H. Wendl. The pest invades trees in three main ways: by laying eggs and incubating them in the crown of the plant, on roots at the surface and at the base of the trunk or petiole. Most of the plants in the genus Trachycarpus are taller, and the damage is concentrated in the middle and upper parts of the plant, making control more difficult. In this paper, we combine 19 bioclimatic variables based on the MaxEnt model to project the current and future distributions of R. ferrugineus under three typical emission scenarios (2.6 W m−2 (SSP1-2.6), 4.5 W m−2 (SSP2-4.5) and 8.5 W m−2 (SSP5-8.5)) in the 2050s and 2090s. Among the 19 bioclimatic variables, five variables were screened out by contribution rates, namely annual mean temperature (BIO 1), precipitation of driest quarter (BIO 17), minimum temperature of coldest month (BIO 6), mean diurnal range (BIO 2) and precipitation of wettest quarter (BIO 16). These five variables are key environmental variables that influence habitat suitability for R. ferrugineus and are representative in reflecting its potential habitat. The results showed that R. ferrugineus is now widely distributed in the southeastern coastal area of China (high suitability zone), concentrating in the provinces of Hainan, Guangdong, Fujian, Guangxi and Taiwan. In the future, the area of high and low suitability zones will increase and the area of medium suitability zones will decrease. The area of low suitability zone will still be in the largest proportion. This study aims to provide a theoretical reference for the future control of R. ferrugineus from the perspective of geographic distribution.