昆虫病原线虫对甘肃省草地蛴螬的致病力研究

Pathogenicity of Entomopathogenic Nematodes to Grass Grubs(Coleoptera:Scarabaeidae)

为提高昆虫病原线虫在草地蛴螬(Scarabaeidae)防治中的应用,以甘肃省采样诱集的28个线虫品系为研究对象,通过实验室致病力测定研究了昆虫病原线虫对草地蛴螬的致病力。结果表明:Steinernema feltiae 0619HT和Heterorhabditis megidis 0627M 2品系对草地蛴螬有较高的致病力。S.feltiae 0619HT品系对华北大黑鳃金龟(Holotrichia oblita)致死时间较短,而H.megidis 0627M品系的累积致病力较强,室内测定昆虫病原线虫侵染草地蛴螬的适合剂量为3200 IJs·H^(-1)。天然草场施用S.feltiae 0619HT和H.megidis 0627M线虫2周后,大栗鳃金龟(Melolntha hippocastanica)虫口减退率分别为83.8%和79.5%。故S.feltiae 0619HT和H.megidis0627M线虫品系对甘肃省草地蛴螬具有较高的防治效果,是一种有效的生防因子。

28 indigenous isolates of entomopathogenie nematodes from Gansu were used in a series of bioas- says against grassland grubs（Holotrichia oblita Fald and Melolntha hippocastanica Menetries）. All iso- lates showed infectivity to H. diomphalia, especially Steinernema feltiae 0619HT and Heterorhabditis megidis 0627M. In pot experiments, S. feltiae 0619HT killed the host within a short time and H. megidis 0627M caused greater mortality as time goes on. The optimal does of EPN in assay against H. oblita was 3200 IJs ·H-1. Similar results were observed in field experiments after applying nematode for 2 weeks, the revision reduced rates of Melolntha hippocastanica after applying S. feltiae 0619HT and H. megidis 0627M in field were 83.8% and 79.5%, respectively. These results overall suggest S. feltiae 0619HT and H. megidis 0627M to be promising biocontrol agents against grass grubs.