Bioassay of infectivity of entomopathogenic nematode Heterorhabditis against Galleria mellonella

Abstract

Entomopathogenic nematodes belonging to the families Steinernematidae and Heterorhabditidae are the natural killers of insect-pests of economically important crops. Entomopathogenic nematodes have a mutualistic association with bacteria and together they employ a synergistic mechanism to kill insect hosts by producing multiple toxins. In this paper, we have explained the protocol for the isolation of entomopathogenic nematodes from the soil and validated their infectivity against the larva of Galleria mellonella. Under this experimentation, an insect baiting technique was used to attract infective juveniles from the soil. The new progeny of nematodes were extracted by using the modified White trap methods. The infectivity was accessed by releasing five to six infective juveniles per larva kept in a small petri dish. The role of Heterorhabditis in infectivity was determined by brick red color development of dead larva, absence of putrefying odor and intactness of dead cadaver. Artificially improved strains of entomopathogenic nematodes can be included in crop protection after accessing their efficacy and compatibility with other components of integrated pest management tactics.