Lethal and sublethal effects of insecticides used in the management of Plutella xylostella (Lepidoptera: Plutellidae) on the predator Cycloneda sanguinea L. (Coleoptera: Coccinellidae)

Abstract

BACKGROUND The application of synthetic insecticides is the main strategy used to reduce the damage caused by the diamondback moth Plutella xylostella in commercial Brassica crops. However, incorrect insecticide use can cause biological and ecological disturbances in agroecosystems. Cycloneda sanguinea is a generalist voracious predator and is distributed widely in cultivated and noncultivated ecosystems. This study investigated the efficiency of four insecticides for the control of P. xylostella and the lethal and sublethal effects of these insecticides on C. sanguinea. RESULTS Spinosad (92% mortality) and chlorfenapyr (76% mortality) were highly toxic to P. xylostela. However, chlorantraniliprole (10% mortality) and methomyl (no mortality) were ineffective against this pest. Chlorantraniliprole was the only insecticide that was highly toxic to C. sanguinea by contact (90% mortality), however, it was nontoxic following the ingestion of chlorantraniliprole‐contaminated aphids. Interestingly, ingestion of prey contaminated with methomyl and chlorfenapyr was highly toxic (100% mortality) to C. sanguinea. Spinosad was nontoxic to C. sanguinea via exposure to contaminated surfaces and following ingestion of contaminated prey. However, direct contact of the insects with both methomyl and spinosad significantly affected C. sanguinea flight activity (vertical flight and free‐fall flight), whereas chlorfenapyr impacted vertical flight only. CONCLUSION These findings showed that chlorantraniliprole was not only ineffective for the control of P. xylostela, but was also highly toxic to C. sanguinea. The results indicated that spinosad was efficient against P. xylostela and was of low toxicity to C. sanguinea; however, the deleterious effects of this insecticide on flight behavior could result in reduced predatory efficiency. © 2022 Society of Chemical Industry.

Toxicity and Sublethal Effects of Fluxametamide on the Key Biological Parameters and Life History Traits of Diamondback Moth Plutella xylostella (L.)

“…In contrast, the sublethal concentrations of cyantraniliprole and beta-cypermethrin did not show any significant effect on the life history of Helicoverpa assulta [48] and P. xylostella [49], respectively. Besides, da Silva et al [50] reported that chlorantraniliprole (<10% mortality) and methomyl (0% mortality) registered very negligible toxicity to P. xylostella at their sublethal levels. This phenomenon might be attributable to the typical symptoms of positive fitness effects of sublethal insecticides exposure to insect pests [51].…”

Lethal and sublethal effects of insecticides on Bathycoelia distincta (Heteroptera: Pentatomidae)

“…Sublethal concentrations of insecticides can affect many physiological parameters such as development, longevity, and fecundity (Zhou et al 2017;Lu et al 2020;Wu et al 2022), as well as mobility (da Silva et al 2022), and feeding behaviour (Koo et al 2015;Zeng et al 2016). These effects can vary according to the species and the insecticides used.…”