Indian Journal of Nematology

Post-application of Heterorhabditis indica in apple orchards to control apple root borer Dorysthene shuegelii, successful recycling was observed only in cadavers exhibiting uniform brick red coloration, unlike in those with uneven coloration and appeared diseased. Impaired life cycle of H. indica was also observed occasionally during routine culturing on Galleria mellonella larvae which too appeared diseased. Dominant bacterial contaminants were isolated from such cadavers, along with the cuticle of H. indica IJs, and characterized using 16S rDNA. The non-symbiotic bacterial contaminants were Bacillus subtilis, B. licheniformis, Staphylococcus cohniiand Acinetobacter rhizosphaerae (D. huegelii), Bacillus bombysepticus, Ochrobactrum anthropi, Ochrobactrum sp. (G. mellonella) and Sphingomonas koreensis, Sphingobacterium sp., Ochrobactrum anthropi (H. indica cuticle). Association of S. koreensis and Sphingobacterium sp. with H. indica cuticle, and B. bombysepticus, which causes black chest septicemia disease in silkworms, with Galleria, is reported for the first time. Such competing contaminants can be a possible threat to the ‘recycling’ attribute of entomopathogenic nematodes when applied as bio-pesticide in fields, and ignorance of hygiene can hamper their in vivo production.