Does spinetoram pose low risk to the neotropical lady beetle Eriopis connexa (Coleoptera: Coccinellidae)?

Abstract

Spinetoram is a new spinosyn recommended against lepidopteran and other defoliating species; while Eriopis connexa (Germar) preys upon aphids. To get additional control for defoliator and aphid species simultaneously it is worth to know the impact of spinetoram on the lady beetles. The impact of spinetoram on different stages of the lady beetle was studied using the field rates 0.08, 0.12, and 2-fold the highest field rate (0.24 g i.a./L). The study used two lady beetle populations: susceptible and resistant to pyrethroids, which is also recommended against defoliating pest species. Spinetoram applied on the egg masses resulted in similar development and hatching for spinetoram rates and lady beetle populations. Egg masses from resistant population treated with higher rates resulted in reduced survival for newly hatched larvae compared to untreated and the lower spinetoram rates. Lady beetle forage on treated surface for prey; but 4th- instar larvae confined on treated leaf exhibited similar developmental duration, pupation, and emergence rates. Larvae of similar age caged on treated leaves with aphids promoting dried residue and contaminated prey ingestion resulted in lower pupation rate at the highest spinetoram field rate for both lady beetle populations. Adult beetles from both populations caged on either spinetoram-dried residues or dried residues plus contaminated aphids exhibited similar egg production and survival. Therefore, responding the question raised with the study, spinetoram caused minor impact on lady beetle larvae and unnoticeable impact on adults; hence, can be another option for insecticide recommendation against lepidopteran larvae and still conserve the lady beetle.