不同种类农药对棉蚜的防治效果及对多异瓢虫的安全性评价

Effectiveness of different pesticides on Aphis gossypii and a safety evaluation of Hippodamia variegata

【目的】筛选对棉蚜Aphis gossypii防治效果较好,对多异瓢虫Hippodamia variegata安全性较高的农药,为轮换施用农药降低棉蚜的抗药性和减少其对多异瓢虫的影响提供理论依据。【方法】本文通过五点取样法和目测法系统调查施用8种不同类型13种不同种类农药后各处理小区棉蚜、多异瓢虫幼虫和成虫的种群数量,评价其对棉蚜的防治效果,对多异瓢虫幼虫和成虫校正虫口减退率及多异瓢虫/棉蚜益害比的影响。【结果】氟啶虫胺腈、氟啶虫酰胺和双丙环虫酯对棉蚜的防治效果较好,药后3、7、10和14 d其防治效果均在73.53%-97.46%,且其处理小区多异瓢虫/棉蚜益害比较高,均在0.0168-0.0927;除啶虫脒、呋虫胺和螺虫乙酯以外,其余10种农药对多异瓢虫幼虫具有较高的安全性。13种农药对多异瓢虫成虫数量的影响均较小,多异瓢虫成虫校正虫口减退率均在6.73%-32.61%,其中呋虫胺、噻虫胺、噻虫嗪、烯啶虫胺和吡蚜酮对其影响最小(7.37%-31.00%);除吡虫啉(药后7 d)、啶虫脒(药后3 d)和呋虫胺(药后3、7和14 d)以外,其余农药对多异瓢虫幼虫和成虫校正虫口减退率的影响均无显著性差异(P>0.05)。【结论】氟啶虫胺腈、氟啶虫酰胺和双丙环虫酯对棉蚜的防治效果较好,对多异瓢虫幼虫安全性较高、对成虫种群数量影响较小且多异瓢虫/棉蚜益害比较高,这3种不同类型农药的轮换施用有助于降低棉蚜的抗药性及对多异瓢虫的影响。

[Objectives]To determine the resistance of Aphis gossypii to different pesticides and identify those that are safer for Hippodamia variegata.[Methods]The number of A.gossypii and H.variegata larvae and adults in each plot after the application of 13 different pesticides from 8 different types was quantified using the five-point sampling and visual methods.The effect of each pesticide on A.gossypii,the corrected rate of decrease of larvae and adults of H.variegata,and the ratio of H.variegata to A.gossypii,were also measured.[Results]A.gossypii were more susceptible to sulfoxaflor,flonicamid and afidopyropen,which at 3,7,10 and 14 days after application had reduced numbers by 73.53%-97.46%,respectively.The ratio of H.variegata to A.gossypii was also higher in plots treated with these pesticides(0.0168-0.0927).With the exception of acetamiprid,dinotefuran and spirotetramat,the other 10 pesticides tested were relatively safer for H.variegata larvae.The effects of all 13 pesticides on H.variegata adults were low;the corrected decrease rate was 6.73%-32.61%.Among the pesticides tested,dinotefuran,clothianidin,thiamethoxam,nitenpyram and pymetrozine had the least effect on H.variegata adults(7.37%-31.00%).Except for imidacloprid(7 days after treatment),acetamipri(3 days after treatment)and dinotefuran(3,7 and 14 days after treatment),there were no significant differences between the corrected decrease rates of H.variegata larvae and adults among the other pesticides.[Conclusion]Sulfoxaflor,flonicamid and afidopyropen are both more effective than the other pesticides tested for the control of A.gossypii,and safer for H.variegata.Alternating the application of these three pesticides could both reduce the development of resistance in A.gossypii and mortality of H.variegata.