Postgrado en Fitosanidad-Entomologia y Acarologia, Colegio de Postgraduados, Km 36.5 Carretera Mexico-Texcoco, Montecillo, Texcoco, Estado de Mexico, 56230, Mexico.
Microb Ecol. 2013 Feb;65(2):437-49. doi: 10.1007/s00248-012-0124-9. Epub 2012 Sep 11.
White grub larvae are important soil-dwelling pests in many regions of Mexico as they attack many important crops such as maize. The use of synthetic chemicals is currently the main control strategy, but they are not always effective; thus, other alternatives are needed. Microbial control using entomopathogenic fungi represents an important alternative strategy, and species within the genera Beauveria and Metarhizium are considered amongst the most promising candidates. Seventeen Beauveria spp. and two Metarhizium spp. isolates were obtained in surveys of white grub larvae from different regions of Guanajuato, Mexico. All isolates were capable of infecting healthy larvae of the white grub Phyllophaga polyphilla in laboratory assays, but mortality never exceeded 50 %. Isolates were identified using morphological and molecular methods. Based on elongation factor1-α and ITS partial gene sequence data, all Beauveria isolates were identified as Beauveria pseudobassiana. Elongation factor1-α and β-tubulin sequence data identified the Metarhizium isolates to be Metarhizium pingshaense. In contrast, three additional Metarhizium isolates obtained the previous year in the same region were identified as M. pingshaense, Metarhizium anisopliae and Metarhizium robertsii. Microsatellite genotyping showed that all B. pseudobassiana isolates were the same haplotype. Enterobacterial Repetitive Intergenic Consensus fingerprinting information confirmed no significant variation amongst the B. pseudobassiana isolates. The ecological role of these isolates and their impact on white grub larvae populations are discussed.
白土金龟幼虫是墨西哥许多地区重要的土壤栖息性害虫，因为它们会攻击许多重要的作物，如玉米。目前，使用合成化学品是主要的控制策略，但它们并不总是有效；因此，需要其他替代方案。利用昆虫病原真菌进行微生物防治是一种重要的替代策略，而在金龟子属和拟青霉属中的物种被认为是最有前途的候选者之一。在对来自墨西哥瓜纳华托不同地区的白土金龟幼虫的调查中，获得了 17 株拟青霉属和 2 株绿僵菌属的分离物。所有分离物都能够在实验室试验中感染健康的白土金龟幼虫，但死亡率从未超过 50%。使用形态学和分子方法对分离物进行了鉴定。基于伸长因子 1-α 和 ITS 部分基因序列数据，所有的拟青霉属分离物均被鉴定为拟青霉属假巴斯德氏菌。伸长因子 1-α 和β-微管蛋白序列数据将绿僵菌分离物鉴定为绿僵菌平沙变种。相比之下，前一年在同一地区获得的另外三个绿僵菌分离物被鉴定为绿僵菌平沙变种、绿僵菌拟青霉属和绿僵菌罗伯茨变种。微卫星基因分型显示，所有拟青霉属假巴斯德氏菌分离物均为同一单倍型。肠杆菌重复基因间一致性指纹信息证实，拟青霉属假巴斯德氏菌分离物之间没有明显的差异。讨论了这些分离物的生态作用及其对白土金龟幼虫种群的影响。
