苯醚威混配剂对印鼠客蚤毒效的观察

OBSERVATION OF THE TOXICITY OF MIXED INSECTICIDES PREPARED WITH FENOXYCARB AND CYPERMETHRIN TO XENOPSYLLA CHEOPIS

为寻求最有效混配浓度,有效防治鼠疫媒介蚤种印鼠客蚤,本文使用药膜法对苯醚威、氯氰菊酯浓度梯度进行毒效试验,通过不同浓度的死亡率观察,直线回归法计算半数致死浓度和相关系数,按比例混合法将两药半数致死浓度转化为剂量然后混合配比为6个剂量组,最后获得最有效配比浓度。结果显示,苯醚威、氯氰菊酯对印鼠客蚤未吸血新羽化成虫的LC_(50)分别为1 647. 9752、8. 4861 mg/L;苯醚威6 mg/L,1 000 mg/L氯氰菊酯混配试剂对印鼠客蚤未吸血新羽化成虫的毒杀效果最佳,24 h死亡率70%,苯醚威和氯氰菊酯混配剂对印鼠客蚤未吸血新羽化成虫有增效作用。

To seek a most suitable proportioning concentration of fenoxycarb and cypermethrin for making a most effective mixed insecticide to control the plague vector fleas Xenopsylla cheopis, toxicity tests were performed with residual smearing method for series proportions of fenoxycarb and eypermethrin. Mortality of tested fleas, median lethal concentration （ LC50 ） and correlation coefficient （r） were calculated with linear regression analysis, six dose groups with different proportions were then set up, and the most effective proportioning concentration of fenoxycarb and cypermethrin was drawn up. The results showed that the median lethal concentration of fenoxycarb and cypermethrin to newly emerged adults of X. cheopis were 1647. 9752 and 8. 4861 mg/L, respectively; the mixed insecticide prepared with fenoxycarb of 6 mg/L and cypermethrin of 1 000 mg/L showed a most effective toxicity to the newly emerged aduh fleas, the 24 h mortality reached to 70%. The mixed insecticide prepared with fenoxycarb and cypermetbrin presented the synergism of toxicity to newly emerged adults of X. eheopis compared to that of single fenoxycarb or cypermethrin.