Campos-Herrera Raquel, Gutiérrez Carmen
Dep. Agroecología, Instituto de Ciencias Agrarias, Centro de Ciencias Medioambientales CSIC, c/ Serrano 115 dpdo, Madrid 28006, Spain.
J Invertebr Pathol. 2009 Feb;100(2):100-5. doi: 10.1016/j.jip.2008.11.009. Epub 2009 Jan 13.
Entomopathogenic nematodes (EPNs) are one of the best non-chemical alternatives for insect pest control, with native EPN strains that are adapted to local conditions considered to be ideal candidates for regional biological control programs. Virulence screening of 17 native Mediterranean EPN strains was performed to select the most promising strain for regional insect pest control. Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) Rioja strain produced 7%, 91% and 33% larval mortality for the insects Agriotes sordidus (Illiger) (Coleoptera: Elateridae), Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), respectively, and was selected as the most promising strain. The S. feltiae Rioja strain-S. littoralis combination was considered the most suitable to develop the Rioja strain as a biocontrol agent for soil applications. The effect of soil texture on the virulence of the Rioja strain against S. littoralis was determined through dose-response experiments. The estimated LC(90) to kill larvae in two days was 220, 753 and 4178 IJs/cm(2) for soils with a clay content of 5%, 14% and 24%, respectively, which indicates that heavy soils produced negative effects on the virulence of the Rioja strain. The nematode dose corresponding to the LC(90) for soils with a 5% and 14% clay content reduced insect damage to Capsicum annuum Linnaeus (Solanales: Solanaceae) plants under greenhouse microcosm conditions. The results of this research suggest that an accurate characterization of new EPN strains to select the most suitable combination of insect, nematode and soil texture might provide valuable data to obtain successful biological control under different ecological scenarios in future field applications.
昆虫病原线虫（EPNs）是害虫防治中最佳的非化学替代方法之一，适应本地条件的本地EPN菌株被认为是区域生物防治计划的理想候选者。对17种地中海本地EPN菌株进行了毒力筛选，以选择最有前景的区域害虫防治菌株。斯氏线虫（Steinernema feltiae）（Filipjev）（小杆目：斯氏线虫科）里奥哈菌株对暗黑叩头虫（Agriotes sordidus）（Illiger）（鞘翅目：叩头虫科）、斜纹夜蛾（Spodoptera littoralis）（Boisduval）（鳞翅目：夜蛾科）和地中海实蝇（Ceratitis capitata）（Wiedemann）（双翅目：实蝇科）幼虫的死亡率分别为7%、91%和33%，该菌株被选为最有前景的菌株。斯氏线虫里奥哈菌株与斜纹夜蛾的组合被认为最适合将里奥哈菌株开发为土壤应用的生物防治剂。通过剂量反应实验确定了土壤质地对里奥哈菌株对斜纹夜蛾毒力的影响。对于粘土含量分别为5%、14%和24%的土壤，估计两天内杀死幼虫的LC(90)分别为220、753和4178条感染期幼虫/cm²，这表明重质土壤对里奥哈菌株的毒力产生负面影响。在温室微观条件下，粘土含量为5%和14%的土壤中与LC(90)相对应的线虫剂量降低了辣椒（Capsicum annuum Linnaeus）（茄目：茄科）植株的虫害损伤。本研究结果表明，准确鉴定新EPN菌株以选择最合适的昆虫、线虫和土壤质地组合，可能会提供有价值的数据，以便在未来田间应用的不同生态场景下实现成功的生物防治。
