Sublethal exposure to spinetoram impacts life history traits and dengue virus replication in Aedes aegypti

Abstract

Insecticides are anthropogenic environmental stressors and also a common stressor for mosquito vectors. However, the use of insecticides is often guided by shortterm efficacy, and the sublethal effect on their target or nontarget species has long been ignored. Here, we analyzed how sublethal exposure of the promising vector-control bioinsecticide spinetoram to Aedes aegypti larvae alter adult performance and susceptibility to dengue virus (DENV) infection. We found that the surviving adult mosquitoes were significantly smaller and exhibited weaker blood-feeding capacity than control females, apart from the extended immature development period. In terms of reproductive potential, although the F 0 generation produced a similar number of eggs and offspring during the first gonotrophic cycle, the survival rates of the F 1 generations were significantly lower as compared to the control group, suggesting transgenerational sublethal effects on the F 1 generation. Notably, surviving adult females had higher DENV-2 viral loads than the control group after spinetoram sublethal exposure. Mechanistically, transcriptomic analysis showed that inhibition of oxidative phosphorylation may function in stimulating DENV production in adult Ae. aegypti. In Aag2 cells, significant accumulation of apoptosis, mitochondrial reactive oxygen species production, and DENV-2 replication by spinetoram exposure consistently support our conclusion. Our study highlights the threat of sublethal spinetoram exposure on outbreaks of mosquito-borne viruses.

Nicotinic Acetylcholine Receptor Alpha6 Contributes to Antiviral Immunity via IMD Pathway in Drosophila melanogaster

“…when exposed to sublethal doses of phoxim [ 29 ]. Escherichia coli -infected Enallagma cyathigerum larvae exposed to 0.5 μg/L chlorpyrifos had a tenfold higher bacterial load than unexposed larvae [ 30 ], while a study by Wang et al (2023) found that Aedes aegypti treated with 10 ng/mL spinetoram during the larval stage had significantly higher amounts of dengue virus after becoming adults than the control [ 31 ]. Our study contributes to this topic by demonstrating that the insecticide spinosad-targeting Dα6 influences many RNA viruses load through interference with the IMD pathway.…”

In silico SNP prediction of selected protein orthologues in insect models for Alzheimer's, Parkinson's, and Huntington’s diseases

“…On applying a sublethal dose of spinosyn insecticides to A. aegypti . Parkinson's disease-related genes were significantly enriched in spinetoram-exposed mosquitoes compared with controls 47 . Through our studies, it showed a high protein identity to human with reasonable query coverage for PARK6, VPS35, ATP13A2 and PLA2G6.…”