Isolation of entomopathogenic nematodes and control of Phyllophaga vetula Horn in Oaxaca, Mexico

Abstract

This study aimed to isolate native entomopathogenic nematodes (EPN) in the Central Valleys of Oaxaca and to determine their potential for control of white grub (Phyllophaga vetula Horn). Fifty-five (55) soil samples were collected in 13 communities in the period August to October 2008 and 29.1% of these were found positive for EPN. Five isolates were selected for their apparent pathogenicity to third instar Galleria mellonella; two of the genus Steinernema and three Heterorhabditis. After evaluating these five isolates for control of white grubs, the Heterorhabditidae EPN presented the lowest values for both lethal dosages and lethal times. Using  polymerase chain reaction (PCR) procedures, the species Heterorhabditis mexicana, Steinernema  carpocapsae and Steinernema feltiae were identified. We concluded that H. mexicana was the most effective isolate for control of P. vetula larvae.

Key words: Entomopathogenic nematodes, Steinernema, Heterorhabditis, bioassays, lethal dosages.