Studies on the entomopathogenicity and bacterial associates of the nematode Oscheius carolinensis

► Oscheius carolinensis is putative entomoparasitic nematode. ► This nematode is consistently associated with four bacterial species. ► One bacterium, Serratia marcescens, is carried on the cuticle of the nematodes. ► O. arolinensis lifestyle depends on its association with its bacteria. ► S. acescens, and Providencia rettgeri facilitate entomopathogenicity. ► All other bacteria allow for a free-living nematode phase.