低剂量杀虫剂与高温结合对西花蓟马种群的防控

Prevention and control of western flower thrips Frankliniella occidentalis by treatment with low doses of pesticides and high temperatures

为了探究低剂量杀虫剂与高温结合防控西花蓟马Frankliniella occidentalis种群的最佳组合,选用啶虫脒、多杀菌素、高效氯氰菊酯和灭多威4种杀虫剂的LC_(50)剂量处理西花蓟马成虫和2龄若虫18~76 h后,分别在41、43、45℃进行2 h热激处理,观察并记录每种组合下西花蓟马的存活情况。结果表明,药剂处理成虫或若虫18 h和28 h后再进行热激处理,西花蓟马的存活率显著低于其它处理。经4种杀虫剂的LC_(50)剂量处理后,不同高温热激均能不同程度降低成虫或若虫种群存活率,热激后存活率显著低于对照组;经灭多威LC_(50)剂量处理的成虫或若虫,再经高温热激处理后的存活率最低,其中45℃热激处理对成虫和若虫的存活率影响最明显,经45℃热激处理18 h和28 h后的成虫存活率为10.1%和5.9%,若虫存活率为6.1%和3.3%。研究表明,杀虫剂LC_(50)剂量与高温热激联合增强了对西花蓟马种群的抑制作用,药剂处理后选择最佳热激时间可最大限度降低西花蓟马的耐热性,进一步增强高温热激的防治效果。

To control western flower thrips Frankliniella occidentalis with the best combination of low- dose pesticide and high temperature, the adults and 2nd instar nymphs were exposed to 41, 43 and 45℃ for 2 h after treated with LCs0 doses of acetamiprid, spinosad, beta-cypermethrin and methomyl for 18- 76 h, and the survival rates were determined. The results showed that the heat-shock survival rates of adults and 2nd instar nymphs were lower at 41, 43 and 45 ℃ after treated with LCs0 doses of four insecti- cides for 18 h or 28 h than those of other treatments. The heat-shock survival rates of adults and 2nd in- star nymphs treated with methomyl were the lowest among all treatments, which had significant differ- ence at 41 ℃ and 43 ℃. The survival rates of adults were 10.1% and 5.9%, and the survival rates of 2nd instars were 6.1% and 3.3% after treated with methomyl for 18 h and 28 h at 45℃, respectively. The re- suits indicated that LCs0 doses of insecticides could improve the inhibitory effect of heat shock on F. oc- cidentalis populations, and the best interval time after pesticide treatment was very critical, which could decrease the heat resistance ofF. occidentalis and strengthen the control efficiency.