Effects of insecticides on the foraging behaviour and survival of Cotesia vestalis, a larval parasitoid of the diamondback moth, Plutella xylostella

Abstract

The effects of the insecticides etofenprox, malathion, diazinon, methomyl, alanycarb, clothianidin and emamectin benzoate on the foraging behaviour and survival of Cotesia vestalis (Hymenoptera: Braconidae), a larval parasitoid of the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) were investigated in the laboratory. The period required for C. vestalis females to reach P. xylostella‐infested Komatsuna (Brassica rapa) plants treated with etofenprox, methomyl or malathion was significantly longer than that to infested plants treated with emamectin benzoate or clothianidin; and the period to reach alanycarb or diazinon‐treated plants was intermediate between them. The period to reach emamectin benzoate‐ or clothianidin‐treated plants was not significantly different from that to distilled water‐sprayed plants, suggesting that etofenprox, methomyl and malathion have strong inhibitory effects on the flight response, whereas the inhibitory effects of alanycarb and diazinon are relatively weak. By contrast, emamectin benzoate and clothianidin showed no inhibitory effect. The time of residency on the clothianidin‐treated plants was significantly longer than that on other insecticide‐treated plants (etofenprox, methomyl, alanycarb, malathion or diazinon), with the time of residency on emamectin benzoate‐treated plants being intermediate between them. These results suggest that etofenprox, methomyl, alanycarb, malathion, and diazinon have a strong inhibitory effect on host‐searching behaviour, while emamectin benzoate and clothianidin have a relatively weak effect. Furthermore, the mortality of wasps after foraging on the clothianidin‐treated plants was significantly higher than after foraging on other insecticide‐treated plants (etofenprox, methomyl or malathion), with subsequent mortality on alanycarb‐, diazinon‐ and emamectin benzoate‐treated plants being intermediate between them. Our results suggest that subsequent mortality increases with decreased inhibitory effect on the foraging behaviour of C. vestalis.

Do Biopesticides Affect the Demographic Traits of a Parasitoid Wasp and Its Biocontrol Services through Sublethal Effects?

“…Emamectin killed 17% and 47% of females and males, respectively, exposed to 1-h old residues. However, higher mortality rates were found in previous studies conducted exposing females of three other braconid species [ Cotesia vestalis (Haliday), C. plutellae Kurdj and Aphidius gifuensis (Ashmead)] to dried residues of emamectin [52]–[54]. These differences could be due to the exposure substrate since overestimation of acute toxicity usually occurs when using pesticide residues on inert material, rather than on plant, such as in our study [11].…”

VALIDATION OF TECHNOLOGY COMPONENTS FOR PEANUT POD BORER (Etiella zinckenellaTriet.) CONTROL

“…The results of this study were supported by Takada 2014, lambda-cyhalothrin and triflumuron insecticides are also safe against the survival of the parasitoid Ganaspidium nigrimanus and T. galloi. Furthermore, emamectin benzoate and clothianidin insecticides were also safe against the behavior and survival of the Cotesia vestalis parasite in citing the caterpillar cabbage Plutella xylostella (Kawazu et al, 2010).…”

Sublethal effects of the insecticidal fusion protein ω -ACTX-Hv1a/GNA on the parasitoid Eulophus pennicornis via its host Lacanobia oleracea

“…19 Furthermore, some insecticides (e.g. malathion, etofenprox and methomyl) can also have strong, sublethal negative effects on foraging behaviour, 20 while others (e.g. chlorpyrifos) can reduce the sex ratio in parasitoid progenies.…”