摘要
Field doses of six selected insecticides were tested against the immature(pupae) and mature (adult) stages of Diadegma semiclausum (Hellen) and Oomyzus sokolowskii(Kurdjumov), parasitoids of the diamondback moth, Plutella xylostella (L.). Effects of contacttoxicity (direct spraying) of the six insecticides on emergence of parasitoids were found negligibleon both species except permethrin which caused 37.5% mortality. All adults of both parasitoidspecies died 24 hours after exposure to chlorfenapyr, emamectin benzoate and permethrin. Incontrast, the three insect growth regulators (IGRs), chlorfluazuron, flufenoxuron and teflubenzuron,were found harmless to both species, and adult mortality of both parasitoid species was 0—16.7%.However, parasitism by the females of both parasitoid species was severely impaired when the femaleswere offered the three IGR diluted solutions for 24 hours. Effects of oral toxicities of the IGRson longevity of both parasitoids after 12 hours exposure were found to be significantly differentbetween males and females. Compatibility of tested insecticides with D. semiclausum and O.sokolowskii and integration of compatible insecticides with these parasitoids in integrated pestmanagement programs of crucifers are discussed.
act Field doses of six selected insecticides were tested against the immature (pupae)and mature (adult) stages of Diadegma semiclausum (Hellén) and Oomyzus sokolowskii(Kurdjumov), parasitoids of the diamondback moth, Plutella xylostella (L.). Effects ofcontact toxicity (direct spraying) of the six insecticides on emergence of parasitoids were found negligible on both species except permethrin which caused 37.5% mortality. All adults of both parasitoid species died 24 hours after exposure to chlorfenapyr, emamectin benzoate and permethrin. In contrast, the three insect growth regulators (IGRs), chlorfluazuron,flufenoxuron and teflubenzuron, were found harmless to both species, and adult mortality of both parasitoid species was 0-16.7%. However, parasitism by the females of both parasitoid species was severely impaired when the females were offered the three IGR diluted solutions for 24 hours. Effects of oral toxicities of the IGRs on longevity of both parasitoids after 12 hours exposure were found to be significandy different between males and females. Compatibility of tested insecticides with D. semiclausum and O. sokolowskii and integration of compatible insecticides with these parasitoids in integrated pest management programs of crucifers are discussed.
