Panonychus citri is one of the most destructive pests in citrus orchards, exhibiting varying degrees of tolerance to numerous insecticides, such as spirodiclofen. To effectively manage pests, this study explores the response of P. citri to spirodiclofen stress from the perspectives of life history, enzymatic parameters, and reproduction. The effects of two concentrations (LC30 and LC50) of spirodiclofen on the biological parameters of P. citri were evaluated by the life table method. The results showed that the development duration, fecundity, oviposition days, and lifespan were shortened, though the pre-oviposition period of two treatments was prolonged in comparison with the control. A significant decrease was recorded in the net reproductive rate (R0) and the mean generation time (T) for the two treatments. Nevertheless, the intrinsic rate of increase (r) and the rate of increase (λ) were not significantly affected in the LC30 treatment, whereas they declined in the LC50 treatment. The enzyme activity assay resulted in higher activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), and carboxylesterase (CarE), among the treatments than the control. In contrast, the treatments recorded lower cytochromeP450 (CYP450) and Glutathione S-transferase (GST) activities than the control. Furthermore, the study detected that relative mRNA expression of Vitellogenin (Vg) and Vitellogenin receptor (VgR) for two treatments were lower than the control. In summary, two concentrations of spirodiclofen inhibited progeny growth and fecundity of P. citri. Additionally, the results of this study may support further research on tolerance of P. citri in response to spirodiclofen stress.

Two-spotted spider mite, Tetranychus urticae Koch (Acari: Prostigmata), is one of the most economically important mite species, mainly controlled by chemical acaricides. Natural enemies have been assessed as reliable alternatives for management of this phytophagous mite. In the current project, demographic characteristics of Neoseiulus californicus McGregor (Acari: Phytoseiidae) to sublethal concentrations (LC10 = 6.76 × 102, LC20 = 8.74 × 103 and LC30 = 55.38 × 103 conidia ml−1) of entomopathogenic fungus, Beauveria bassiana (Bals.) Vuill. TV strain were investigated under laboratory conditions at 25 ± 2°C, 70 ± 5% RH and a photoperiod of 16:8 (L:D) h. Our results indicated that when adult predators were exposed to LC20 and LC30 of B. bassiana, the oviposition period was significantly reduced compared with other treatments. Neoseiulus californicus fecundity was significantly greater in the control (37 eggs) than in LC30 (24 eggs). Life table analysis revealed that the net reproductive rate (R0) declined as the sublethal concentrations of B. bassiana increased. The most striking result to emerge from the data is that not only intrinsic (r); but also, finite rate of increase (λ) was not significantly affected by different concentrations of B. bassiana. Our findings revealed some potential interactions of B. bassiana and N. californicus during their combinations for managing T. urticae that may be helpful for optimising control of this important pest.

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.

Gene expression studies in organisms are often conducted using reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), and the accuracy of RT-qPCR results relies on the stability of reference genes. We examined ten candidate reference genes in Sclerodermus guani, a parasitoid wasp that is a natural enemy of long-horned beetle pests in forestry, including ACT, EF1α, Hsc70, Hsp70, SRSF7, α-tubulin, RPL7A, 18S, 28S, and SOD1, regarding variable biotic and abiotic factors such as body part, life stage, hormone, diet, and temperature. Data were analysed using four dedicated algorithms (ΔCt, BestKeeper, NormFinder, and geNorm) and one comparative tool (RefFinder). Our results showed that the most stable reference genes were RPL7A and EF1α regarding the body part, SRSF7 and Hsc70 regarding the diet, RPL7A and α-tubulin regarding the hormone, SRSF7 and RPL7A regarding the life stage, and SRSF7 and α-tubulin regarding temperature. To ascertain the applicability of specific reference genes, the expression level of the target gene (ACPase) was estimated regarding the body part using the most stable reference genes, RPL7A and EF1α, and the least stable one, SOD1. The highest expression level of ACPase was observed in the abdomen, and the validity of RPL7A and EF1α was confirmed. This study provides, for the first time, an extensive list of reliable reference genes for molecular biology studies in S. guani.

Drosophila suzukii is a pest of global concern due to its great impact on several crops. The entomopathogenic nematode Steinernema carpocapsae was highly virulent to the larvae of the fly although some immune mechanisms were triggered along the infection course. Thus, to understand the gene activation profile we performed a comparative transcriptome of D. suzukii larvae infected with S. carpocapsae and Xenorhabdus nematophila to map the differentially expressed genes involved in the defence response. The analysis exposed the induction of genes involved in the humoral response such as the antimicrobial peptides and pattern-recognition receptors while there was a suppression of the cellular defence. Besides, genes involved in melanisation, and clot formation were downregulated hindering the encapsulation response and wound healing. After the infection, larvae were in a stress condition with an enrichment of metabolic and transport functionalities. Concerning the stress response, we observed variations of the heat-shock proteins, detoxification, and peroxidase enzymes. These findings set a genetical comprehensive knowledge of the host-pathogen relation of D. suzukii challenged with S. carpocapsae which could support further comparative studies with entomopathogenic nematodes.

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.

Spodoptera littoralis (Boisd) (Lepidoptera: Noctuidae) is a highly polyphagous insect that significantly reduces agricultural production of several food staples. We evaluated performance of S. littoralis on several meridic diets based on various maize hybrids, including Oteel, Simon, Valbum, SC703, and SC704. Growth, feeding behaviours, and activity of digestive enzymes of S. littoralis were examined under laboratory conditions. In addition, selected biochemical characteristics of maize hybrid seeds were evaluated, including starch, protein, anthocyanin, as well as phenolic and flavonoid contents, to examine relationships between plant properties and digestive performance of S. littoralis. Performance of S. littoralis on maize hybrids, as measured by nutritional indices, was related to both proteolytic and amylolytic activities quantified using gut extracts. Larval S. littoralis reared on SC703 exhibited the highest efficiency of conversion of digested food, while the lowest was recorded in those fed on the Oteel hybrid. S. littoralis reared on SC703 and Oteel also exhibited the highest and lowest relative growth rates, respectively. The highest levels of proteolytic activity in S. littoralis were measured from larvae reared on the SC703 hybrid, while the lowest levels occurred on the Oteel and Valbum hybrids. Amylolytic activity was lowest in larvae reared on SC703 and Valbum hybrids and highest in larvae reared on the Oteel hybrid. Our results suggest that the SC703 hybrid was the most suitable host for S. littoralis, while the Oteel hybrid demonstrated the greatest level of tolerance against S. littoralis of those evaluated. We discuss the potential utility of maize hybrids exhibiting tolerance traits against this cosmopolitan pest with reference to cultivation of tolerant varieties and identification of specific tolerance traits.

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.

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.

Dietary restriction-influenced biological performance is found in many animal species. Pardosa pseudoannulata is a dominant spider species in agricultural fields and is important for controlling pests. In this study, three groups – a control group (CK group), a re-feeding group (RF group), and a dietary restriction group (RT group) – were used to explore development, mating, reproduction, and the expression levels of Vg (vitellogenin) and VgR (vitellogenin receptor) genes in the spider. The findings indicated that when subjected to dietary restriction, the carapace size, weight of the spiderlings, and weight of the adults exhibited a decrease. Furthermore, the preoviposition period and egg stage were observed to be prolonged, while the number of spiderlings decreased. It was also observed that re-feeding reduced cannibalism rates and extended the preoviposition period. Dietary restriction also affected the expression of the Vg-3 gene in the spider. These results will contribute to the understanding of the impact of dietary restriction in predators of pest control, as well as provide a theoretical foundation for the artificial rearing and utilisation of the dominant spider in the field.

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.

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.

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.

Aphis gossypii is one of the most economically important agricultural pests that cause serious crop losses worldwide, and the indiscriminate chemical application causes resistance development in A. gossypii, a major obstacle to successful control. In this study, we selected the up-regulated expression gene AgJHAMT, which was enriched into juvenile hormone pathway though transcriptome sequencing analysis of the cotton aphids that fed on transgenic cotton lines expressing dsAgCYP6CY3 (the TG cotton). The AgJHAMT gene was overexpressed in cotton aphids which fed on the TG cotton, and its expression profile during the nymphs was clarified. Then, silencing AgJHAMT could advance the developmental period of cotton aphids by 0.5 days compared with control groups. The T and t values of cotton aphids in the dsJHAMT treatment group (6.88 ± 0.15, 1.65 ± 0.06) were significantly shorter than that of the sprayed H2O control group (7.6 ± 0.14, 1.97 ± 0.09) (P < 0.05), respectively. The fast growth caused by AgJHAMT silencing was rescued by applying the JH analogue, methoprene. Overall, these findings clarified the function of AgJHAMT in the developmental period of A. gossypii. This study contributes to further clarify the molecular mechanisms of delaying the growth and development of cotton aphids by the transgenic cotton lines expressing dsAgCYP6CY3.

The touchstone of the ‘New Synthesis’ was population cytogenetics –rather than genetics – due to the abundant polymorphic inversions in the genus Drosophila. Grasshoppers were not a material of choice because of their conservative karyotypes. However, nowadays seven species of Acrididae were described for polymorphic centric fusions, five of them in South-America. Leptysma argentina and the likely biocontrol of water-hyacinth Cornops aquaticum are semiaquatic Leptysminae (Acrididae: Orthoptera), polymorphic for centric fusions, supernumerary segments and a B-chromosome. We sought to demonstrate the operation of natural selection on them, by detecting: (I) latitudinal clines; (II) regression on environmental variables; (III) deviation from null models, such as linkage equilibrium; (IV) seasonal variation; (V) comparison between age classes and (VI) selection component analyses. All of them were confirmed in L. argentina, just (I) and (II) in C. aquaticum. Furthermore, the relationship between karyotype, phenotype and recombination was confirmed in both species. Karyotype–phenotype relationship may be due to the body enlargement the fusions are associated with, along with a latitudinal transition in voltinism. Karyotype-related recombination reduction in both species may help explain all fusion clines, although there is probably more than one factor at work. No effects were noticed for a supernumerary segment in L. argentina, but it is ubiquitous and certainly non-neutral. C. aquaticum is poised for introduction in South-Africa as a biocontrol of water-hyacinths; the recent discovery of four more segment polymorphisms may imply more chromosomal markers to make sense of its genetic system.