Unravelling the impact of insecticides on biocontrol agent Amblyseius andersoni (Chant): Insights from Laboratory studies.

Insecticides are extensively used in farming practices to control pests; however they could unintentionally harm beneficial organisms like biocontrol agents. Amblyseius andersoni (Chant) (Acari: Phytoseiidae) is one of the main biocontrol agents for managing spider mites and thrips, two major pests which cause significant damage to many crops. A. andersoni is highly sensitive to insecticides, which are often used to control spider mites. Maintaining compatibility between pesticides and biocontrol agents is a major challenge in agriculture, especially in perennial cropping systems. In our study, we aimed to explore the dose response effect of three A. andersoni strains to deltamethrin. Two of these strains were collected from commercial apple orchards in the Veneto region of Italy. We also evaluated the impact of deltamethrin on the fecundity of A. andersoni. Furthermore, side-effects of etofenprox and spinosad on survival and fecundity of A. andersoni were assessed. Two strains, which were collected from commercial apple orchards exhibited high resistance level but the fecundity decreased with the increase in insecticide dose. The strains which was highly resistant to deltamethrin survived the recommended field dose of etofenprox but displayed susceptibility towards spinosad. The other deltamethrin-resistant strain displayed lower susceptibility when exposed to recommended field dose of both etofenprox and spinosad. This study demonstrates that presence of resistant A. andersoni to pyrethoids can be used within integrated pest management strategies.