长期使用拟除虫菊酯类杀虫剂对印鼠客蚤染蚤率的影响分析

Effect of long-term usage of pyrethroid insecticides on the infection rate of Xenopsylla cheopis

目的分析在鼠疫疫区(强化灭蚤区)长期使用拟除虫菊酯类杀虫剂对印鼠客蚤染蚤率的影响,为今后工作中合理选择杀虫剂提供科学理论依据。方法通过统计各区域捕获鼠数和印鼠客蚤染蚤鼠数,求得印鼠客蚤染蚤率,采用SPSS软件比较强化灭蚤区(隆林县、西林县)与对照区(右江区)印鼠客蚤染蚤率有无差异。结果隆林县、西林县(强化灭蚤区)与右江区(对照区)在1—3月染蚤率较低,自4月开始逐渐上升,6月达到高峰,之后逐渐下降,3条曲线变化趋于一致。右江区、隆林县、西林县捕获鼠的印鼠客蚤染蚤率分别为33.93%、29.74%和30.38%,无显著差异性(P>0.05)。结论在鼠疫疫区长期使用拟除虫菊酯类杀虫剂,强化灭蚤区与对照区鼠体印鼠客蚤染蚤率无显著性差异,说明该类杀虫剂灭蚤作用减弱,效果下降,印鼠客蚤可能对拟除虫菊酯类杀虫剂产生抗药性。

Objective To analyze the long term effect of pyrethroid insecticides on Xenopsylla cheopis(X.cheopis) infection rate of the rats captured in plague-infected areas(depulization areas),and provide scientific basis for the rational selection of pesticides in future work.Methods The infection rate of X.cheopis was obtained by counting the number of fleas from the captured rats.The infection rate of X.cheopis in the depulization areas(Longlin County,Xilin County) was compared with that in the control area(Youjiang District) by using SPSS software.Case-control analysis was conducted in Youjiang District,Longlin County and Xilin County.The infection rate of X.cheopis was calculated by dividing the number of infections in fleas by the number of all captured rats.The differences between the infection rate of X.cheopis in the depulization areas(Longlin County,Xilin County) and in the control area(Youjiang District)were examined by using chi-square test.All the statistical analyses were conducted in SPSS software.Results Both depulization areas(Longlin County,Xilin County) and control area(Youjiang District) had similar trends in the infection rates of X.cheopis.The infection rates were low from January to March.They began to rise gradually in April and peaked in June,and then declined gradually.The infection rates of X.cheopis in Youjiang District,Longlin County and Xilin County were respectively 33.93%,29.74% and 30.38%,with little statistical difference among them.Conclusion There was no significant difference in the flea infection rate of X.cheopis between the depulization areas and the control areas,indicating that X.cheopis might develop some resistance to pyrethroid insecticides.