Department of Entomology and Plant Pathology, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, Brazil.
Lett Appl Microbiol. 2013 Aug;57(2):157-63. doi: 10.1111/lam.12090. Epub 2013 May 20.
Entomopathogenic fungi are potential candidates for use in integrated vector management. However, efficient delivery systems for these fungi need to be investigated. It is known that adult mosquitoes are attracted to dark surfaces, and therefore, black cotton cloths impregnated with Metarhizium anisopliae alone or in combination with the insecticide imidacloprid (IMI) were tested under laboratory conditions. Black cloths impregnated with fungus were also tested in large-cage trials under natural extradomicile conditions. Blood-fed Rockefeller and wild-type strain Aedes aegypti had higher levels of survival when compared with sucrose-fed counterparts following exposure to fungus-impregnated cloths. However, when blood-fed A. aegypti were exposed to a combination of M. anisopliae + IMI, the survival rates were statistically equal to those of sucrose-fed females. Large-cage trials showed significant decreases in A. aegypti survival following a minimum 12 h exposure of the mosquitoes to fungus-impregnated cloths. Increased exposure times results in further reductions in survival. The synergism between M. anisopliae and IMI resulted in reduced survival rates independent of feeding regime under laboratory conditions. Fungus-impregnated cloths tested under simulated field conditions, considered to be unfavourable for fungal infection, resulted in significant reductions in adult A. aegypti survival. We are currently testing the combined use of fungi and insecticides against blood-fed insects under simulated field conditions.
The use of fungus-impregnated cotton cloths is a promising point source application method for the control of adult Aedes aegypti, and this strategy could be incorporated into an integrated vector management programme aiming to reduce the incidence of dengue fever.
昆虫病原真菌是综合病媒管理的潜在候选者。然而，需要研究这些真菌的有效传递系统。已知成蚊会被深色表面吸引，因此，在实验室条件下，单独用绿僵菌或与杀虫剂吡虫啉（IMI）一起浸渍的黑棉布以及黑棉布进行了测试。在自然环境下的大型笼中试验中，也对带有真菌的湿布进行了测试。与对照的食糖水的雌蚊相比，接触浸有真菌的布的吸血洛克菲勒和野生型埃及伊蚊（Aedes aegypti）的存活率更高。然而，当吸血的 A. aegypti 接触到绿僵菌+IMI 的混合物时，其存活率与食糖水的雌蚊在统计学上相等。大型笼中试验表明，在蚊子接触浸有真菌的布至少 12 小时后，埃及伊蚊的存活率明显下降。暴露时间的增加会导致存活率进一步下降。在实验室条件下，绿僵菌和 IMI 之间的协同作用导致存活率降低，而与摄食状态无关。在模拟野外条件下测试的浸有真菌的布，被认为不利于真菌感染，导致成年埃及伊蚊的存活率显著降低。我们目前正在模拟野外条件下，测试真菌和杀虫剂联合使用对吸血昆虫的效果。
浸有真菌的棉布是控制埃及伊蚊成虫的有前途的点状应用方法，这种策略可以纳入旨在降低登革热发病率的综合病媒管理计划。
