Abstract
Maximizing crop yields relies on the use of agrochemicals to control insect pests. One of the most widely used classes of insecticides is the neonicotinoids but these can also disrupt crop-pollination services provided by bees. Here, we analysed the impact of chronic exposure to the neonicotinoid thiamethoxam on gene expression and alternative splicing in brains of Africanized honey bees, Apis mellifera. We find differentially regulated genes that show concentration-dependent responses to thiamethoxam. Most have no annotated function but encode short Open Reading Frames (sORFs), a characteristic feature of anti-microbial peptides. We show that intrinsically sub-lethal thiamethoxam exposure makes bees more vulnerable to pathogenic bacteria. Our findings imply a synergistic mechanism for the observed bee population declines that concern agriculturists, conservation ecologists and the public.
Competing Interest Statement
The authors have declared no competing interest.