昆虫病原线虫对韭蛆和土壤线虫群落的影响

防治韭菜的主要地下害虫韭蛆（迟眼蕈蚊Bradysia odoriphaga）是造成韭菜农药残留超标主要原因。室内实验表明,生物天敌昆虫病原线虫Steinernema feltiae处理60h后,韭蛆杀死率显著高于使用农药的对照组。2010年4月18日在山东省寿光市丰城地区韭菜地施用昆虫病原线虫以防治韭菜的主要害虫韭蛆,同时以施用化学农药辛硫磷作为对照,处理后第35d和第175d调查结果表明,昆虫病原线虫处理组的昆虫病原线虫多度显著高于化学对照组,其中第175d调查结果表明,经昆虫病原线虫处理后的韭菜鲜重比化学农药处理的对照组增加了10.4%,但差异未达到显著效果。上述结果表明,昆虫病原线虫能够有效控制韭蛆危害。第35d取样结果表明,昆虫病原线虫处理组的土壤线虫群落Shannon多样性指数高于化学农药处理组;第175d调查结果表明,两种处理之间土壤线虫群落各指标相近。试验结果表明昆虫病原线虫能够有效防治韭蛆。

Effect of Entomopathogenic Nematodes on Controlling Bradysia odoriphage Yang et Zhang and Soil Nematode Community

Using pesticide to control Bradysia odoriphage Yang et Zhang, the main pathogen for leek production, has caused high risk of pesticide contamination. We evaluated the effects of entomopathogenic nematodes（EPN） on controlling B. odoriphage under laboratory and field conditions, and the pesticide was included as control. The field trial was set up on April 18th, 2010 in Fengcheng, Shouguang, Shandong Province, China. The results showed that the Bradysia odoriphage mortality was significant higher at 60 h in EPN inoculation under laboratory condition. The number of EPN（No. per 100 g dry soil） in the EPN treatment was significantly higher than those in the pesticide treatment both at 35 days and 175 days after inoculation（ DAI ）. The fresh weight of leek sampled at 175 DAI was not decreased in the EPN treatment, and even increased 10.4% as compared to the pesticide treatment although the difference was not significant. It indicated that EPN could successfully control the damage of B. odoriphage. The Shannon diversity index in EPN treatment was significant greater than those in the pesticide treatment at 35 DAI but not at 175 DAI. The results showed that entomopathogenic nematodes（EPN ） could effectively control Bradysia odoriphage Yang et Zhang.