Detoxification and neurotransmitter clearance drive the recovery of Arma chinensis from ß-cypermethrin-triggered knockdown.

ABSTRACT

Natural enemies of arthropods contribute considerably to agriculture by suppressing pests, particularly when combined with chemical control. Studies show that insect recovery after insecticide application is rare. Here, we discovered the recovery of the predatory bug Arma chinensis from knockdown following the application of ß-cypermethrin but not five other insecticides. A. chinensis individuals were more tolerant to ß-cypermethrin than lepidopteran and coleopteran larvae, which did not recover from knockdown. We assessed A. chinensis recovery by monitoring their respiration and tracking locomotion through the entire process. We identified and verified the trans-regulation of detoxifying genes, including those encoding cytochrome P450s and α/ß-hydrolase, which confer recovery from ß-cypermethrin exposure in A. chinensis, by mitogen-activated protein kinase (MAPK) and cAMP response element binding protein (CREB). Furthermore, we discovered a novel mechanism, the neurotransmitter clearance, in vivo during the recovery process, by which the insect initiated the removal of excessive dopamine with a degrading enzyme ebony. Overall, these results provide mechanistic insights into the detoxification and neurotransmitter clearance that jointly drive insect recovery from insecticide exposure.