Spodoptera exigua is a polyphagous pest of diverse crops and causes considerable economic losses. The overuse of chemical insecticides for controlling this pest results in insecticide resistance, environmental pollution and toxicity to other non-target organisms. Therefore, a sustainable and efficient way for pest management is urgently required. In this study, laboratory bioassays of eleven commonly used insecticides, the specific entomopathogen of S. exigua (Spodoptera exigua multiple nucleopolyhedrovirus, SeMNPV), and SeMNPV-insecticide combinations against the S. exigua laboratory population and two field populations were tested. Our results indicated that the two field populations had developed resistance to almost half of the tested insecticides, while SeMNPV had good virulence in all populations. Interestingly, the combined use of SeMNPV enhanced the toxicity of the tested insecticides against all populations to a different extent and considerably reduced the insecticide resistance of S. exigua field populations or even recovered the susceptibility to above insecticides. Furthermore, the field trial showed that the combined application of SeMNPV contributed to promoting the control efficacy of emamectin benzonate and chlorfenapyr. These results provide a promising efficient way for pest resistance management and an environmentally friendly approach for controlling S. exigua with the combined application of nucleopolyhedroviruses and insecticides.

Two closely related thrips species, Frankliniella occidentalis and Frankliniella intonsa, are important pests on agricultural and horticultural crops. They have several similarities, including occurrence patterns, host range, and aggregation pheromone compounds. However, there are very few reports about the chemosensory genes and olfactory mechanisms in these two species. To expand our knowledge of the thrips chemosensory system, we conducted antennal transcriptome analysis of two thrips species, and identified seven odorant-binding proteins (OBPs) and eight chemosensory proteins (CSPs) in F. occidentalis, as well as six OBPs and six CSPs in F. intonsa. OBPs and CSPs showed high sequence identity between the two thrips species. The RT-qPCR results showed that the orthologous genes FoccOBP1/3/4/5/6, FintOBP1/3/4/6, FoccCSP1/2/3, and FintCSP1/2 were highly expressed in male adults. Molecular docking results suggested that orthologous pairs FoccOBP4/FintOBP4, FoccOBP6/FintOBP6, and FoccCSP2/FintCSP2 might be involved in transporting the major aggregation pheromone compound neryl (S)-2-methylbutanoate, while orthologous pairs FoccOBP6/FintOBP6, FoccCSP2/FintCSP2, and FoccCSP3/FintCSP3 might be involved in transporting the minor aggregation pheromone compound (R)-lavandulyl acetate. These results will provide a fundamental basis for understanding the molecular mechanisms of pheromone reception in the two thrips species.

The gut microbiota of insects, shaped by extensive coevolution, plays a crucial role in host adaptability and ecological expansion. The fall armyworm (Spodoptera frugiperda J.E. Smith), a highly polyphagous and migratory invasive pest, infests more than 350 plant species worldwide, resulting in substantial crop losses and increased reliance on pesticide applications. In this study, we employed 16S rRNA high-throughput sequencing to investigate diet-induced alternations in the gut microbial communities of larvae fed corn, rice, or an artificial diet. The results showed that diet significantly influenced microbial diversity, with rice-fed larvae exhibiting the highest richness. Firmicutes, Proteobacteria, and Cyanobacteria were the predominant bacterial phyla. Genus-level analysis revealed notable diet-dependent shifts, with Enterobacter and other genera (e.g., Ochrobactrum and Allorhizobium–Neorhizobium–Pararhizobium–Rhizobium) only detected in plant-fed groups. Additionally, current findings suggest that gut microbial genera are more prevalent when S. frugiperda larvae feed on rice plants than on corn plants or an artificial diet and are closely linked to their metabolic activities. Dominant microbial genera are expected to support essential metabolic processes and exhibit increased abundance on rice. These results indicate that the gut microbiome of S. frugiperda is diet-driven reorganization, potentially facilitating its polyphagy. This study extends the current understanding by elucidating the specific gut microbial taxa and their putative metabolic associations that are responsive to diet in S. frugiperda, thereby providing a theoretical basis for its polyphagous capability and underscoring microbiota-based strategies for sustainable pest management.

Predatory insects serve as important biological control agents in ecosystems by efficiently reducing pest populations. Orius strigicollis is a highly effective beneficial predator in cultivated fields in China. It is widely used as a biological control agent against many pests, including thrips, aphids, and spider mites. The lack of public availability of O. strigicollis genomes has limited our ability to thoroughly explore and research its evolution and gene function, particularly genes related to pesticide resistance. Here, we report a chromosome-scale assembly of the O. strigicollis genome by PacBio High fidelity (HiFi) long-reads, high-throughput chromosome conformation capture (Hi-C) and Illumina sequencing technologies. The final genome assembly was 167 Mb with a scaffold N50 size of 12.49 Mb, and 97.87% of the assembly was anchored to 12 chromosomes. Annotation identified 11,551 protein-coding genes. In this article, we reported a high-quality chromosome-scale assembly genome for the species of the genus Orius for the first time, which provide valuable resources for functional gene research and genetic transformation of natural enemy insects.

Phenacoccus solenopsis Tinsley is a highly invasive pest threatening global cotton production and numerous cultivated crops. The sterile insect technique (SIT), based on γ-ray irradiation, offers a sustainable and eco-friendly alternative to chemical controls for managing pests. This study aimed to determine the optimal developmental stage and radiation dose to induce sterility in P. solenopsis. Male pupae aged 5 days demonstrated the highest tolerance to irradiation among all tested age groups. These 5-day-old male pupae were irradiated with 20, 40, 60, and 100 Gy and mated with unirradiated females, and the effects on mating rate, oviposition stage, egg number, egg hatchability, male adult lifespan, and female sex ratio were assessed. Sterility was effectively induced by 60 Gy in males without compromising their mating competitiveness in the parental (F₀) generation. Moreover, sterility traits were inherited by descendants, leading to a progressive decline in population size across the F₁ and F₂ generations. Therefore, a 60 Gy dose was identified as optimal for suppressing P. solenopsis in field settings. These findings establish a theoretical foundation for implementing SIT as a regional pest management strategy for P. solenopsis.