Performance of the lady beetle Eriopis connexa to sequential exposure to selective insecticides prevailed over its pyrethroid resistance

Authors: LIRA, ROGERIO - Federal Rural University Of Pernambuco; FERREIRA, ELLEN - Federal Rural University Of Pernambuco; BARBOSA, PAULO - Federal University - Brazil; Simmons, Alvin; TORRES, JORGE - Federal Rural University Of Pernambuco

Submitted to: BioControl
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/24/2023
Publication Date: 1/31/2023
Citation: Lira, R., Ferreira, E.E., Barbosa, P.R., Simmons, A.M., Torres, J.B. 2023. Performance of the lady beetle Eriopis connexa to sequential exposure to selective insecticides prevailed over its pyrethroid resistance. BioControl. 68:397-409. https://doi.org/10.1007/s10526-023-10180-y.
DOI: https://doi.org/10.1007/s10526-023-10180-y

Interpretive Summary: Insecticides are commonly used to control pests such as aphids and caterpillars in brassica crops such as collard and kale. A study was conducted to assess the impact of several commercial insecticides on the population of Eriopis connexa, a lady beetle insect predator, in cole crops. Among eight evaluated insecticides (cyantraniliprole, chlorantraniliprole, chlorfenapyr, deltamethrin, spinosad, spiromesifen, methomyl, and pymetrozine), there were no negative impact on egg laying or survival of the beetle, even though food consumption by the beetle was affected in some cases. Results from this study will help support the agricultural community in insecticide resistance management and integrated pest management in cole crops.

Technical Abstract: Conservation biological control techniques support insecticide resistance management (IRM) and integrated pest management (IPM) by restraining pest resurgence and outbreaks of secondary pests by carefully selecting the insecticides to be applied. The lady beetle Eriopis connexa (Germar) (Coleopotera: Coccinellidae) is among the natural enemies in agricultural systems of brassica crops and their populations may be disrupted by exposure to insecticides. Pyrethroid-resistant (EcViR) and pyrethroid-susceptible (EcFM) E. connexa larvae and adults were exposed to eight insecticides (cyantraniliprole, chlorantraniliprole, chlorfenapyr, deltamethrin, spinosad, spiromesifen, methomyl, and pymetrozine) that target different pests of brassica crops. Evaluations were conducted on larval and adult survival, larval developmental time, fecundity and egg viability across 30d, and consumption of Lipaphis pseudobrassicae (Davis) (Hemiptera: Aphididae) or larvae of Plutella xylostella (L.) (Lepidoptera: Plutellidae) 24h after exposure to the insecticides. In addition, the levels of aphids and DBM infestation in field cages were evaluated as a function of insecticide application and release of the lady beetles. Neither survival of larvae and adult beetles, nor fecundity, were affected by the insecticides. EcFM females exposed to residues of spinosad and methomyl consumed a greater number of aphids compared to the pyrethroid-resistant females. Likewise, EcFM beetles exposed to deltamethrin residues consumed more DBM larvae than EcViR beetles. There was no additive effect of the control of these pests when lady beetles were used alone or with insecticides. Results from this study help deploy IRM and IPM in brassica crops. We showed the compatibility of the natural enemy with insecticides through multiple exposures targeting different pest species combining different insecticide modes of action.