Phthorimaea absoluta, an important pest of tomato crops, has reportedly developed high levels of resistance to the insecticide chlorantraniliprole, which has a unique mode of action and high efficacy. This study evaluated the sustained multigenerational effects of chlorantraniliprole on P. absoluta, focusing on resistance development, growth, development, reproductive capacity, population parameters, and nutritional indicators. After continuous selection with sublethal chlorantraniliprole for eight generations (CX-Sub₈), bioassays showed that CX-Sub₈ had 225.37-fold higher resistance than the susceptible strain. The age-stage, two-sex life table analysis revealed that the preadult development time and mean generation time were significantly prolonged, while population reproduction and pupal weight were reduced. Moreover, the relative fitness of CX-Sub₈ was 0.62, and changes in the life table parameters correlated with an increase in the serial number of selection cycles. The second-instar larvae of CX-Sub₈ presented lower triglyceride, glycerol, trehalose, free fatty acid, and protein contents than the unselected strain (CX-S₈). Transcriptome analysis identified 2517 differentially expressed genes, with most being enriched in nutrient metabolism-related pathways, such as amino acid biosynthesis and fatty acid degradation metabolism. These results indicate that multigenerational sublethal chlorantraniliprole treatment disrupts the nutritional metabolism, and inhibits the growth, development, and reproduction of P. absoluta.

Plant volatiles play a critical role in mediating insect host location behavior and offer eco-friendly alternatives for chemical control. Monolepta signata is a widespread phytophagous pest in East Asia that poses a significant threat to various crops. In this study, we evaluated the electrophysiological and behavioral responses of adult M. signata to 26 binary and ternary mixtures of 13 plant-derived volatile compounds extracted from cotton and corn leaves. Electroantennogram (EAG) recordings revealed that females exhibited the strongest responses to mixtures 20, 23, and 12, whereas males were the most responsive to mixtures 26, 19, and 4. Y-tube olfactometer assays showed significant behavioral attraction of females to mixtures 1, 20, 23, and 26, and males to mixtures 19, 22, and 23. Field trials demonstrated that mixtures 22, 23, and 26 attracted significantly more adults than the control, with mixture 23 (α-phellandrene + trans-2-hexen-1-ol + 1-heptene) achieving the highest trap capture. These findings highlight the potential of specific volatile blends, especially ternary mixtures, as effective attractants of M. signata, and support their application in environmentally sustainable pest monitoring and management strategies.