草坪常用化学药剂对昆虫病原线虫存活和侵染率的影响

Effects of the Chemical Insecticides Used in Turfgrass Maintenance on the Mortality and Infectivity of Entomopathogenic Nematodes

测定了草坪上常用的14种化学药剂对蝼蛄斯氏线、长尾斯氏线虫X-7品系和小卷蛾斯氏线虫All品系存活和侵染率的影响.杀虫剂乙酰甲胺磷在高浓度和推荐浓度下对蝼蛄斯氏线虫、长尾斯氏线虫和小卷蛾斯氏线虫的致死率分别为21%和9.5%,13%和5.5%,5.5%和2%;敌百虫在高浓度和推荐浓度下对蝼蛄斯氏线虫的致死率分别高达94.5%和92.5%,在高浓度下对长尾斯氏线虫的致死率为8%,对小卷蛾斯氏线虫没有明显致死作用;克蛾宝对3种线虫的致死作用均比乙酰甲胺磷和敌百虫低.杀菌剂对3种线虫的存活均无影响.除草剂2,4-D丁酯对3种线虫低浓度和高浓度下致死率分别为2%、6%、3.5%和5%、85.5%、6%.经化学药剂处理24h后的线虫侵染黄粉虫9～11龄幼虫,对线虫存活没有影响或者影响较小的化学药剂对线虫的侵染率都没有明显的影响,但剂型为10%可湿性粉剂的吡虫啉对长尾斯氏线虫,以及高浓度的2,4-D丁酯对小卷蛾斯氏线虫的侵染率有明显抑制作用.

The effects of 14 chemical insecticides used in turfgrass maintenance on the mortality and infectivity of three entomopathogenic nematode species, S. scapterisci （Ss）, Steinernema longicaudum X-7 （X-7） and Steinernema carpocapsae All （Sc-All）, were determined. At high and recommended concentration, the mortality of Ss, X-7 and Sc-All caused by acephate were 21% and 9.5 %, 13 % and 5.5 %, 5.5 % and 2 %, respectively. Trichlorfon killed 94.5 % and 92.5 % of Ss at high and recommended concentration respectively, and 92.5 % of X-7 at high concentration, while showed no significant mortality to Sc-All. Keebao was less toxic to three species of the test nematodes than acephate and trichlorfon. 2,4-D was also toxic to Ss, X-7 and Sc-All, mortality of three species of the test nematodes were 2 %, 6 %, 3.5 % and 5 %, 85.5 %, 6 % at recommended and high concentration, respectively. The IJs incubated in chemical insecticide solutions for 24h were used to infect 9-11 instars Tenebrio molitor larvae. 2,4-D at high concentration and imidacloprid which formulation was 10% wettable powders significantly inhibited the infectivity of Sc-All and X-7, respectively. It was showed that the effects of different chemical insecticides on the mortality and infectivity were different; three nematodes species showed different sensitivities to the chemical insecticides.