Heterorhabditis bacteriophora

Abstract

Heterorhabditis bacteriophora is an insect parasite that first gained popularity as a means of agricultural pest control, but has also become a model for nematode parasitism. As an entomopathogenic nematode, H. bacteriophora serves as an obligate host for the Gram-negative bacteria Photorhabdus spp.; together, these symbiotic partners infect numerous insect species. When in contact with a potential host, the parasitic nematode enters through natural openings or pierces the cuticle of the insect to gain entry to the hemocoel, releasing the Photorhabdus spp. bacteria. Nematode virulence is influenced by the age of the infective juveniles. Using immunomodulatory strategies that interfere with innate immune signaling and function, the nematode–bacterial complex evades the insect host defense, which leads to increased virulence and accelerated insect death. H. bacteriophora is closely related to other Heterorhabditis spp. and is a burgeoning model for entomopathogenic nematode infections.