昆虫病原线虫与吡虫啉混用对异迟眼蕈蚊幼虫的毒力测定

Virulence of entomopathogenic nematodes and imidacloprid to Bradysia odoriphaga

【目的】为了解决生产中韭菜异迟眼蕈蚊(Bradysia difformis Frey)防治难、农药残留超标等问题,将昆虫病原线虫与高效低毒的化学杀虫剂减量混用,是一种高效环保的防控手段.【方法】以甘肃省分离得到的优良昆虫病原线虫Steinernema feltiae 0619HT品系,高效低毒农药吡虫啉为研究材料,采用药膜法测定了吡虫啉原药单用、与昆虫病原线虫斯氏线虫Steinernema feltiae 0619HT品系混配,对韭菜异迟眼蕈蚊幼虫的室内毒力,并计算毒力回归方程及致死中浓度LC_(50),以评价线虫与吡虫啉混用对韭菜异迟眼蕈蚊的控制效能.【结果】昆虫病原线虫Steinernema feltiae 0619HT品系,以1 000 Ijs/mL与低剂量10 mg/L的吡虫啉混配,韭菜异迟眼蕈蚊幼虫的校正死亡率达73.3%,比单用吡虫啉(校正死亡率为43.3%)的毒力更高(P<0.05).【结论】昆虫病原线虫与低剂量吡虫啉混用,对异迟眼蕈蚊的毒力增强,具有明显的增效作用,可起到吡虫啉减量增效的效果.

【Objective】To find out the environment-friendly biocontrol application to control Bradysia difformis which damages leek by using the mixture of entomopathogenic nematode(EPN)and low dose of low toxicity pesticides.【Method】The control efficiency of mixture of an native EPN Steinernema feltiae 0619HT in Gansu and imidacloprid against B.difformis was tested with insecticide-impregnated filter method,and the virulence regression equation and LC 50 value were obtained.【Result】The mortality rate for larvae of B.difformis was 73.3% under the condition of 1000 IJs/mL S.feltiae 0619HT and 10 mg/L of imidacloprid,and it was 43.3% while only imidacloprid was used.【Conclusion】The control efficiency of imidacloprid against B.difformis larvae could be enhanced by mixing EPN and EPN could reduce the application amount of imidacloprid.