Predation performance and survival of susceptible and pyrethroid-resistant Eriopis connexa Germar (Coleoptera: Coccinellidae) to insecticides used in brassica crops.

Abstract

Selective insecticides and insecticide-resistant natural enemies are components of chemical and biological methods that can be compatible in an integrated pest management program. Many insecticides that are labeled for treatment against insects in Brassica crops have lost their efficacy because of the development of resistance. However, natural enemies can provide an important role in regulating the population of these pests. Survival of both E. connexa populations was >80% when exposed to the insecticides, except for EcFM exposed to indoxacarb and methomyl. Bacillus thuringiensis, cyantraniliprole, chlorfenapyr, and spinosad caused high mortality of P. xylostella larvae, but neither affected E. connexa survival nor its predation upon L. pseudobrassicae. Cyantraniliprole, chlorfenapyr, deltamethrin, and methomyl caused high mortality of L. pseudobrassicae, but did not affect E. connexa survival nor its predation upon P. xylostella larvae. According to differential selectivity index (DSI) and the risk quotient (RQ), chlorfenapyr and methomyl was most toxic to P. xylostella larvae compared to E. connexa, whereas indoxacarb was more toxic to E. connexa. This study demonstrates that the insecticides B. thuringiensis, cyantraniliprole, chlorantraniliprole, deltamethrin, chlorfenapyr, spinosad, azadiracthin, and spiromesifen are compatible with adult E. connexa within an integrated pest control program in Brassica crops and would be considered to preserving this natural enemy. This article is protected by copyright. All rights reserved.