化学杀虫剂对昆虫病原线虫侵染韭菜迟眼蕈蚊能力的影响

Evaluation of the effects of infection by different entomopathogenic nematodes and chemical pesticides on Bradysia odoriphaga

【目的】为提高昆虫病原线虫对韭菜迟眼蕈蚊Bradysia odoriphaga的防治效果,将昆虫病原线虫与环境友好型化学杀虫剂混用是一条有效途径。【方法】本研究测试了70%吡虫啉水分散颗粒剂、40%毒死蜱乳油和4.5%高效氯氰菊酯乳油对昆虫病原线虫Heterorhabdits bacteriophora Taishan strain H06品系、Steinernema carpocapsae strain SF-SN和All品系存活及侵染率的影响,及低剂量化学杀虫剂与昆虫病原线虫混用对韭蛆3龄幼虫的作用效果。【结果】高效氯氰菊酯(含量为2.00、0.40、0.20和0.10μg·mL-1)和吡虫啉(25.00、5.00、2.50和1.25μg·mL-1)对H.bacteriophora H06和S.carpocapsae All的存活无显著影响,3品系线虫毒死蜱(8.00μg·mL-1)对3品系线虫的致死率均显著高于对照;不同浓度的毒死蜱对3品系线虫的致死率存在显著差异。3种药剂分别与3品系线虫混合后处理韭蛆,韭蛆的死亡率明显高于线虫和杀虫剂单用处理。药后3 d,SF-SN与毒死蜱(8.00μg·mL-1)、吡虫啉(25.00μg·mL-1)和高效氯氰菊酯(2.00μg·mL-1)混合处理韭蛆,分别比单用杀虫剂提高防效34.20%、21.18%、54.99%,优于另外两种线虫与3种药剂混用的效果。【结论】供试线虫中,SF-SN品系与上述杀虫剂联合防治韭蛆效果最好。

Objectives To increase the effectiveness of controlling Bradysia odoriphaga with entomopathogens nematodes, and to screen pesticides as synergists for entomopathogens nematodes. [Methods] The survival rate and infectivity of three entomopathogenic nematodes （Heterorhabdits bacteriophora Taishan strain H06、Steinernema carpocapsae strain SF-SN and All） was tested after dipping them in three kinds of commonly used pesticides （70%imidacloprid wettable granule agent, 40%chlorpyrifos emulsifying concentrate and 4.5%beta-cypermethrin emulsifying concentrate）. Impacts on on 3nd instar larvae of Bradysia odoriphaga of treatment with different combinations of the nematodes and low concentrations of pesticides were determined. [Results] Beta-cypermethrin （2.00、0.40、0.20 and 0.10 μg·mL-1） and imidacloprid （25.00、5.00、2.50 and 1.25 μg·mL-1）, had no effect on the survival of the nematodes. The lethality of a concentration of 8.00 μg·mL-1 chlorpyrifos emulsifying concentrate to all three nematodes at was significantly higher than that of the control, and mortality of the three nematode species was significantly different when treated with different concentrations of chlorpyrifos emulsifying concentrate. After 3 d, mortality of B. odoriphaga treated with a combination of low concentration chlorpyrifos （8.00 μg·mL-1）,＆amp;nbsp;imidacloprid （25.00 μg·mL-1） and beta-cypermethrin （2.00 μg·mL-1） with SF-SN was higher than when treated with any one pesticide alone;lethality being improved by 34.20%, 21.18%, and 54.99%respectively. The mortality of B. odoriphaga treated with the SF-SN-insecticide combination was higher than that of those treated with the other combination. [Conclution] The combination of SF-SN with the three kinds of insecticides appears an effective way of controlling B. odoriphaga.