论文部分内容阅读
目的研究苏云金杆菌对媒介蚊虫的防治效果以及菌液在室内的持效性。方法选择对媒介蚊虫具有高致病力的血清型苏云金杆菌缓释悬浮剂(B.t.H-14)防治试验区蚊虫,分别利用勺捕法和人帐诱法调查蚊幼虫和成蚊密度,与对照区蚊虫密度比较,研究B.t.H-14的现场防治效果,并在实验室观察苏云金杆菌在不同水体内的持效性。结果利用苏云金杆菌防治媒介蚊虫,在媒介蚊虫高峰季节,相关密度指数(RPI)<10,说明苏云金杆菌可以控制自然水体内媒介蚊虫的种群数量。试验区蚊虫密度维持在较低水平,幼虫密度<50条/勺,成蚊密度<20只/h,而对照区蚊虫密度随季节变化明显,幼虫密度>100条/勺,成蚊密度最高可达188只/h。在实验室内,苏云金杆菌持效期可达30 d,其中,在清水中苏云金杆菌的防治效果最好,污染水体苏云金杆菌对蚊幼虫的杀灭率在1周后达到最大值,以后逐渐降低。结论在自然环境中可利用苏云金杆菌防治媒介蚊虫,并根据蚊虫密度,施用不同浓度的菌液和确定施药次数。
Objective To study the control effect of Bacillus thuringiensis on vector mosquitoes and the efficacy of Bacillus thuringiensis in the laboratory. Methods The mosquitoes with high virulence serotype BtH-14 were selected to control the mosquitoes in the test area. The density of mosquito larvae and adult mosquitoes was scoped by scoop-trap method and human-tent trap method respectively. Mosquito density compared to study the effect of BtH-14 on-site control, and in the laboratory observed Bacillus thuringiensis in different water body retention. Results The use of Bacillus thuringiensis to control vector mosquitoes showed that RPI was less than 10 in the season of vector mosquito, suggesting that Bacillus thuringiensis could control the population of vector mosquitoes in natural water. The density of mosquitoes in the experimental area was kept at a low level, the density of larva was less than 50 / spoon and the density of adult mosquito was <20 / h, while the density of mosquito in the control area changed obviously with season, the density of larva was> 100 / Up to 188 / h. In the laboratory, Bacillus thuringiensis persistence period up to 30 d, of which Bacillus thuringiensis control effect in water is best, the killing rate of Bacillus thuringiensis in contaminated water mosquito larvae reached a maximum after 1 week, then gradually decreased . Conclusion Bacillus thuringiensis could be used to prevent and control vector mosquitoes in the natural environment. According to the density of mosquitoes, different concentrations of bacteria solution were applied and the times of application were determined.