甘肃省昆虫病原线虫区系研究

为查明甘肃省昆虫病原线虫的种类及区系分布，通过大蜡螟诱捕法对甘肃省昆虫病原线虫资源进行了调查，分离得到昆虫病原线虫种群51个，分属于8个种：斯氏线虫属（Steinernema）5种，异小杆线虫属（Heterorhabditis）3种。其中斯氏属3个种A，B，C和异小杆1个种D属于国内新记录种。调查表明：甘肃省昆虫病原线虫的优势种为Steinernema feltiae，昆虫病原线虫的分布与土壤类型及植被类型关系密切，沙壤土和壤土中线虫检出率分别为12.2%和8.8%，较粘土5.3%的检出率高，且在果园、菜地和大田中的线虫检出率分别为10.4%，9.2%和5.2%，较未耕地3.3%的检出率高，说明沙壤土和壤土适于昆虫病原线虫的种群建立，且在有农事活动的地块中昆虫病原线虫分布较多。

Occurrence of Entomopathogenic Nematodes in Gansu Province

Soil samples were collected from different areas in Gansu Province and the entomopathogenic nematodes (EPN) were extracted with Galleria mellonella trapping method in order to clarify the species and distribution of EPN in the areas. A total of 51 populations belong to 8 species isolated from soil samples, among which 5 species are Steinernema glaseri, while 3 species are Heterorhabditis glaseri. The results showed that 3 species of Steinernema (A, B, C) and 1 species of Heterorhabditis (D) are new species in China, and the dominant species of EPN in Gansu is Steinernema feltiae. The occurrence of EPN is closely related to plant species and soil types. The prevalence rates of EPN in silty-loam (12.2%) and loam (8.8%) are higher than that in clay (5.3%), while the prevalence rates of EPN in orchard (10.4%), vegetable fields (9.2%) and crop fields (5.2%) were higher than that in uncultivated soil (3.3%). These results show that both silty-loam and loam are suitable for the population establishment of entomopathogenic nematodes, and entomopathogenic nematodes distribute more in the land intervened by human being.