Is there a common mechanism of neonicotinoid resistance among insects? Preliminary results show that F1 larvae of pre-exposed Chironomus xanthus are more tolerant to imidacloprid

Imidacloprid (IMI) belongs to the group of the first generation of neonicotinoids, known for their toxic effects to non-target invertebrate species. Neonicotinoids have a specific mode of action that mimics acetylcholine, impairing the cholinergic neurotransmission, ultimately affecting the survival of organisms. This research aimed to determine the effects of a commercial formulation based on IMI on survival, and life traits parameters to larvae of parental (P) and F1 generations of the non-target insect Chironomus xanthus. C. xanthus is a bioindicator species of environmental change of great ecological relevance in tropical freshwater systems. The 48-h LC50 of IMI was 23.72 & mu;g/L. Environmentally relevant concentrations of IMI impaired the development of larvae, delayed emergence and diminished the fecundity and fertility rates. However, a physiological adaptation of C. xanthus larvae from the parental generation to the filial generation can be suggested. This finding seems to be a key factor determining the resistance to neonicotinoids in pest species. Further biochemical studies should be carried out to unravel possible physiological adaptations focused on detoxification processes and variability of nicotinic receptors that allow the increase of resistance over generations of insect species of interest.

Automated summary

This study found that environmentally relevant concentrations of IMI have negative effects on the development of non-target insect C. xanthus larvae, but a potential physiological adaptation from parental generation to filial generation may determine the resistance to neonicotinoids in pest species.