几种有机磷类杀虫药剂对美洲斑潜蝇活性的研究

Studies on Insecticidal Activity of Several Organophosphorus Insecticides against Vegetable Leafminer Liriomyza sativae (Diptera Agromyzidae)

测定了有机磷类农药毒死蜱、乐果、马拉硫磷、敌敌畏对美洲斑潜蝇各龄幼虫、雌成虫的毒力，进行了成虫取食及产卵的选择、非选择试验和田间小区试验。结果表明：美洲斑潜蝇１、２、３龄幼虫、雌成虫对毒死蜱最敏感，１、２、３龄幼虫对毒死蜱的ＬＣ５０分别是０．０６８２、０．１２１６、０．１４２３ｇ／Ｌ，雌成虫对毒死蜱２４ｈ、４８ｈ的ＬＣ５０分别是０．１５７１和０．１３０４ｇ／Ｌ；毒死蜱对美洲斑潜蝇的取食、产卵拒避持效期分别是６天和８天，用浓度０．４８ｇ／Ｌ毒死蜱处理２、４、６、８天后接虫，幼虫的存活率分别为０、１８．８％、４６．２％和７６．５％；田间用浓度０．４８、０．３２ｇ／Ｌ分别处理，６天的校正虫口减退率分别为９１．０７％和８６．３９％。

The toxicity of several organophosphorus insecticides chlorpyrifos,dimethoate,malathion and dichlorvos to the larvae and female adult of Liriomyza sativae was determined. The adult eating and egg laying repellent in choice and no choice assays were also investigated. The results indicated that the 1st,2nd and 3rd instar larvae and female adult of leafminer were very sensitive to chlorpyrifos,the LC 50 of the 1st,2nd and 3rd instar larvae was 0.0682,0.1216 and 0.1423 g/L respectively. For female adult,the LC 50 at 24h,48h by residue bioassay were 0.1571 and 0.1304 g/L;The adult eating and fecundity was inhibited by chlorpyrifos for 6d and 8d respectively. When the adult was exposed to the leaves which had been treated with 0.48 g/L chlorpyrifos,the larval survival rates at 2d,4d,6d and 8d were 0,18.8%,46.2% and 76.5% respectively. The results from field trials showed that the population density of leafminer reduced 91.07% and 86.39% after treated with 0.48 and 0.32 g/L chlorpyrifos respectively.