Converse V, Grewal P S
Department of Entomology, OARDC, Ohio State University, Wooster 44691-4096, USA.
J Econ Entomol. 1998 Apr;91(2):428-32. doi: 10.1093/jee/91.2.428.
Predictability is a key challenge in biological control of white grubs with entomopathogenic nematodes. Most field test failures have been attributed to the use of inappropriate nematode strains. We evaluated several species and strains of entomopathogenic nematodes (Heterorhabditidae and Steinernematidae) against chafer Cyclocephala hirta in a soil and pot bioassay at 25 degrees C. The NJ65 strain of Steinernema glaseri, isolated from New Jersey, outperformed all other steinernematid and heterorhabditid nematodes, resulting in a 76.5% larval mortality within 3 d of treatment at 125 nematodes per larva. After 6 days of treatment, 4 strains of S. glaseri (NJ21, NJ29, NJ42, and NJ65) achieved 100% larval mortality. Other strains that caused > 80% larval mortality after 6 d of treatment included NJ32, NJ40, and NJ41 of S. glaseri, and Chino Hill, Merced, and Nebraska strains of Heterorhabditis sp. Steinernema anomali (Ryazan), Steinernema kushidai (Hamakita), Heterorhabditis megidis (HO1), and H. bacteriophora (HP88) caused only 45, 55, 60, and 66.7% larval mortality, respectively. Steinernema feltiae (Argentina strain) caused only 16% larval mortality, and Steinernema carpocapsae (All and Mexican strains) and Steinernema scapterisci (Colon strain) were nonpathogenic to C. hirta. Steinernema riobravis caused no larval mortality at 25 degrees C, but inflicted 45-71% mortality at 30 degrees C. Our studies indicate that S. glaseri and Heterorhabditis spp. are most virulent among entomopathogenic nematodes toward C. hirta larvae and certain strains of S. glaseri are superior to Heterorhabditis spp.
对于利用昆虫病原线虫进行蛴螬的生物防治而言，可预测性是一项关键挑战。大多数田间试验失败都归因于使用了不合适的线虫菌株。我们在25摄氏度的土壤和盆栽生物测定中，评估了几种昆虫病原线虫（异小杆线虫科和斯氏线虫科）对鳃金龟Cyclocephala hirta的防治效果。从新泽西分离出的斯氏线虫NJ65菌株，其表现优于所有其他斯氏线虫和异小杆线虫，在每头幼虫接种125条线虫处理3天后，幼虫死亡率达76.5%。处理6天后，4株斯氏线虫（NJ21、NJ29、NJ42和NJ65）实现了100%的幼虫死亡率。处理6天后导致幼虫死亡率>80%的其他菌株包括斯氏线虫的NJ32、NJ40和NJ41，以及异小杆线虫的奇诺山、默塞德和内布拉斯加菌株。异常斯氏线虫（梁赞）、串珠斯氏线虫（滨北）、大异小杆线虫（HO1）和嗜菌异小杆线虫（HP88）分别仅导致45%、55%、60%和66.7%的幼虫死亡率。斯氏侧尾线虫（阿根廷菌株）仅导致16%的幼虫死亡率，而小卷蛾斯氏线虫（All和墨西哥菌株）以及短体斯氏线虫（科隆菌株）对鳃金龟无致病性。里氏斯氏线虫在25摄氏度时未导致幼虫死亡，但在30摄氏度时造成45 - 71%的死亡率。我们的研究表明，斯氏线虫和异小杆线虫在昆虫病原线虫中对鳃金龟幼虫的毒性最强，且某些斯氏线虫菌株优于异小杆线虫。
