两种多杀菌素剂型对三带喙库蚊幼虫现场防治评价

目的评估多杀菌素不同剂型Natular G30(颗粒剂)和Natular T30(片剂)在大型野外模拟水稻田小区中控制三带喙库蚊幼虫的效果。方法选择海口市美兰区灵山镇作为研究现场,利用牛帐诱法采集三带喙库蚊饱血成蚊,带回实验室蚊种复核鉴定,待其产卵孵化出幼虫后,释放于现场模拟稻田的人造小区中。实验小区(n=25)施洒Natular G30和Natular T30,对照小区(n=12)不施洒杀虫剂。定期记录实验前后各小区蚊幼及蛹的数量,计算减退率。试验前,记录实验小区内相关水质指标,如pH、温度、总固体含量、盐度、溶解氧含量等。利用SPSS17.0和Excel2007进行统计分析。结果 Natular T30处理后第1天三带喙库蚊大龄幼虫减退率为10.14%,处理后2周内三带喙库蚊大龄幼虫及蛹减退率均低于80%。Natular G30处理24 d后三带喙库蚊大龄幼虫减退率达到70.06%。结论在大型野外试验中,多杀菌素Natular G30较Natular T30对三带喙库蚊控制持效期长。

Field control evaluation of two spinosad formulations against Culex tritaeniorhynchus

Objective To assess the duration of efficacy of two formulations of spinosad, Natular G30 and Natular 330, in large-scale field trials against Cx. tritaeniorhynchus in simulated paddy field in Haikou city China. Methods The current study was conducted in Lingshan, Meilan District, Haikou City. Adult Culex tritaeniorhynchus was col- lected by cattle bed net trapping method. The mosquitoes collected in field were identified in the laboratory then the larvae of Cx. tritaeniorhynchus were emerged and released in simulated paddy field. Natular G30 and Natular T30 were applied in experiment group （n = 25 ） while no insecticides in control group （n = 12 ）. The number of larvae and pu- pae were recorded regularly, and the reduction rate of older larvae and pupae was calculated. Prior to the trial, some physical and chemical indicators such as pH, temperature, total solids content, salinity and dissolved oxygen of water quality were tested. Results When Natular T30 were applied, the third instar and fourth instar larvae of Cx. tritae- niorhynchtts decreased by 10.14% at the first day after the application. Two weeks later, the reduction rates of third instar, fourth instar larvae and pupae were less than 80%. When Natular G30 were applied, the third insta and fourthinstar larvae of Cx. tritaeniorhynchus decreased by 70.06% after 24 days of the treatment. Conclusion Natular G30 held a longer efficacy than Natular T30 in simulated paddy field.