Lucanidae (Coleoptera: Scarabaeidae) are fascinating beetles exhibiting significant dimorphism and are widely used as beetle evolutionary study models. However, lacking high-quality genomes prohibits our understanding of Lucanidae. Herein, we proposed a chromosome-level genome assembly of a widespread species, Prosopocoilus inquinatus, combining PacBio HiFi, Illumina, and Hi-C data. The genome size reaches 649.73 Mb, having the scaffold N50 size of 59.50 Mb, and 99.6% (647.13 Mb) of the assembly successfully anchored on 12 chromosomes. The BUSCO analysis of the genome exhibits a completeness of 99.6% (n = 1,367), including 1,362 (98.5%) single-copy BUSCOs and 15 (1.1%) duplicated BUSCOs. The genome annotation identifies that the genome contains 61.41% repeat elements and 13,452 predicted protein-coding genes. This high-quality Lucanidae genome provides treasured genomic information to our knowledge of stag beetles.

Slugs are significant agricultural pests and act as vectors for zoonotic parasites. However, current molluscicide options are limited and associated with substantial environmental risks. This study investigates the role of aldehyde dehydrogenase (ALDH) in the biosynthesis of farnesoic acid (FA), a key intermediate in the sesquiterpenoid hormone pathway, in two slug species: Philomycus bilineatus and Laevicaulis alte. Transcriptomic analysis revealed that both species possess conserved sesquiterpenoid biosynthetic pathways, yet they exhibit distinct levels of ALDH gene expression and differences in FA content. RNA interference (RNAi)-mediated gene silencing was employed to validate the potential of these candidate genes as targets for molluscicide development. Structural modeling of ALDH proteins using AlphaFold2 demonstrated notable divergence in the architecture of their active sites, suggesting species-specific enzymatic properties. Citral, a known inhibitor of ALDH, significantly reduced FA production in vivo and exhibited contact toxicity against both slug species. The lethal concentration 50 (LC₅₀) values were determined to be 378.2 g/L for P. bilineatus and 85.2 g/L for L. alte, respectively. Molecular docking analyses indicated that citral binds within the conserved substrate-binding tunnel of ALDH, potentially inhibiting the oxidation of farnesal. These findings establish ALDH as a critical enzymatic target for disrupting endogenous hormone biosynthesis in slugs and support the development of novel, eco-friendly molluscicides targeting the sesquiterpenoid pathway.

Spodoptera frugiperda is a highly destructive migratory pest that severely restricts global agricultural production. Chemical insecticides remain the primary means of field population control, yet the resistance evolution risk of S. frugiperda to two commonly applied insecticides, lufenuron and chlorfenapyr, remains poorly clarified in China. In this study, we found that the four field S. frugiperda populations collected from Jiangsu, Guangxi, Guizhou, and Yunnan Provinces exhibited susceptible or low-level resistance to chlorfenapyr, lufenuron, emamectin benzoate, and spinetoram. However, moderate resistance to chlorantraniliprole (resistance ratio > 5) was detected in the Guangxi and Guizhou populations, consistent with regional variation in diamide insecticide pressure. After 10 consecutive generations of indoor resistance screening, the selected resistant strains showed only 2.89-fold and 3.40-fold resistance increases to lufenuron and chlorfenapyr, respectively, indicating an extremely slow resistance development rate. Furthermore, the lufenuron-resistant and chlorfenapyr-resistant strains displayed negligible cross-resistance to emamectin benzoate, chlorantraniliprole, and spinetoram. Significant fitness costs were detected in both resistant strains, with marked declines in multiple growth, development and reproductive indicators. Collectively, these findings confirm that Chinese field S. frugiperda populations have a low evolutionary risk of resistance to lufenuron and chlorfenapyr, and resistance emergence is constrained by obvious fitness trade-offs. This study provides empirical evidence and theoretical guidance for the scientific formulation of S. frugiperda chemical control and resistance management strategies in China, while highlighting the need for region-specific monitoring of diamide resistance.

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a polyphagous pest exposed to plant defensive chemicals. We tested whether sustained selection by the potato steroidal glycoalkaloid α-solanine induces changes in tolerance, life-history performance, and physiology. A potato-sprout-derived preparation was standardized for α-solanine content by targeted LC–ESI–MS/MS, and a selected line was maintained for 12 generations on a diet containing 1.0 mg α-solanine g⁻¹. Selected and unselected lines were compared across normal artificial diet, α-solanine diet, and potato foliage using bioassays, life-history analyses, detoxification-enzyme assays, untargeted metabolomics, and RT-qPCR. By generation 12, the selected line reached a tolerance ratio of 3.52. Under α-solanine exposure, selection shortened larval, pupal, adult, and total development and increased pupation, adult emergence, and egg hatch, while pupal mass and fecundity did not differ significantly between lines. The selected line showed faster demographic turnover. Carboxylesterase activity differed between lines, whereas CYP450 and GST responses were diet-dependent. Metabolomic contrasts indicated a reduced feature-level response to α-solanine in the selected line, and RT-qPCR revealed constitutive and diet-dependent shifts in detoxification- and stress-related genes. Thus, sustained α-solanine selection generated coordinated multilevel remodeling that improved performance under α-solanine exposure and altered responses to potato foliage.