Age-related Susceptibility of Spodoptera litura Larvae to Some Insecticides

담배거세미나방 유충의 영기별 약제 감수성

In the laboratory study, the toxicities of chlorpyrifos-methyl, chlorpyrifos, etofenprox, etofenprox+PAF' and deltamethrin for different larval instars of S. litura decreased significantly as larvae aged. LCso values for chlorpyrifos- methyl and chlorpyrifos increased significantly from 3rd instar larvae, while those for etofenprox+PAP and deltamethrin-increased from 2nd instar larvae. In pot study, no significant differences in control efficacy were observed among each treated plots and over 90% control efficacy at 5 d after treatment was obtained in all of the treated plots, except treatment with deltamethrin. Therefore four insecticides excluding deltamethrin will be effective for controlling S. litura. However, it will be probably important to select appropriate insecticides and decide a proper time of treatment because the developmental stage is a significant factor in deciding insecticide efficacy because various developmental stages of the tobacco cutworm inhibit in fields.

실내에서 담배거세미나방의 영기별 약제감수성을 조사한 결과 시험된 약제 모두 유충의 영기가 높아질수록 약제감수성은 낮았다. Chlorpyrifors-methyl과 chlorpyrifos의 독성은 3령부터, etofenprox+PAP와 deltamethrin은 2령부터 현저히 떨어졌다. 포트시험결과 deltamethrin을 제외한 4약제 모두 90% 이상의 방제가를 보여 담배거세미나방의 방제에 유용하게 사용될 수 있을 것으로 생각된다. 하지만 야외에서 담배거세미나방은 전 영기가 혼재되어 있고 영기별 약제감수성이 다르기 때문에 적절한 약제선택은 물론 유충 발생초기에 약제를 살포하는 것이 중요하다.