The weakest link: Haploid honey bees are more susceptible to neonicotinoid insecticides

Neonicotinoid insecticides are currently of major concern for the health
of wild and managed insects that provide key ecosystem services like
pollination. Even though sublethal effects of neonicotinoids are well
known, there is surprisingly little information on how they possibly
impact developmental stability, and to what extent genetics are involved.
This holds especially true for haploid individuals because they are
hemizygous at detoxification loci and may be more susceptible. Here we
take advantage of haplodiploidy in Western honey bees,
Apis mellifera, to show for the first time that neonicotinoids
affect developmental stability in diploid females (workers), and that
haploid males (drones) are even more susceptible. Phenotypic fore wing
venation abnormalities and fluctuating wing asymmetry, as measures of
developmental instability, were significantly increased under
field-realistic neonicotinoid-exposure of colonies. The higher
susceptibility of haploid drones suggests that heterozygosity can play a
key role in the ability to buffer the sublethal effects of neonicotinoids.
Aiming to improve conservation efforts, our findings highlight the urgent
need to better understand the role that genetics plays at enabling
non-target organisms to cope with insecticide exposure.