Sublethal toxicity, transgenerational effects, and transcriptome expression of the neonicotinoid pesticide cycloxaprid on demographic fitness of Coccinella septempunctata

Evaluating side effects of new neonicotinoids in terms of sublethal doses and transcriptome expression is a crucial but challenging part of integrated pest management (IPM) approaches. To this end, a study of lethal and sublethal effects on Coccinella septempunctata larvae was conducted, and an age-stage, two-sex life table procedure was performed to investigate life-table parameters. Cycloxaprid (CYC) was shown to have adverse effects on survival, development, total longevity, reproductive capacity, and predation ability in C. septempunctata. In addition, demographic growth parameters of the F1 generation such as net reproductive rate, and the intrinsic and finite rates of increase were significantly decreased under sublethal dosage LR30 (1.91 g ai/hm2). These results demonstrated that the population growth of C. septempunctata was impacted by a sublethal dosage of CYC. For transcriptome expression, 544 up- and 338 down-regulated significantly differentially expressed genes (DEGs), were observed between LR30 treatment and control groups. Moreover, pathways related to metabolism of retinol, carcinogenesis, biosynthesis of steroid hormone, P450 metabolism, and metabolism of xenobiotics were identified in KEGG pathway analysis. Ten DEGs were chosen and confirmed with quantitative real-time PCR analysis. Based on these findings, CYC should be considered as a component of IPM strategies in the field.