小菜蛾孢虫病及其对寄主种群控制效应的研究

A disease in Plutella xylostella caused by a microsporidium and its impact on the host were studied, supported by the National Natural Science Foundation of China. The pathogen of the disease belongs to the genus Vairimorpha and is different from the known species from diamondback moth according to its life cycle, parasitic characters and the results of the electron as well as light microscopy. The pathogen preferentially infected midgut tissue and silk gland but spread to almost all tissues. It was transmitted horizontally mainly by feces as well as transovarially and infected some other lepidopterous species. The median lethal dose (LD50) was 1.799×104 spores per second instar larva. The median lethal time (LT50) was 2.715～4.888 days at doses 5.496×106～2.198×105spores per larva. The pathogen reduced the food consumption and eggs production significantly. It was concluded that Vairimorpha sp. has sufficient potential to be a biocontrol agent for P. xylostella

通过室内和田间试验，研究小菜蛾孢虫的生物学特性和对环境的适应性、持久力及对小菜蛾的致病机理和传播机制。研究引起田间孢虫病传播流行和控制寄主种群的方法及有关因素以及小菜蛾孢虫在小菜蛾综合治理中的作用。测定孢虫病对高等动物的安全性，并研究孢子大量增殖的方法，为小菜蛾的生物防治提供一种新型天敌。