Morphological and molecular characterization of Heterorhabditis bacteriophora isolated from Indian soils and their biocontrol potential

Agricultural soils and open fields from Western Uttar Pradesh (India) were surveyed to determine the presence of entomopathogenic nematodes. From the entomopathogenic nematodes isolated, Heterorhabditis isolates were selected and further characterized using morphological, morphometrical and molecular approaches. The results showed that three isolated nematodes were Heterorhabditis bacteriophora and were associated with Photorhabdus laumondii subsp. clarkei bacteria, while the rests were identified as Heterorhabditis indica. The biocontrol potential of H. bacteriophora against three agricultural pests was evaluated. Nematode infectivity experiments showed that the nematode isolates DH7 and DH8 were highly pathogenic against cotton bollworm (Helicoverpa armigera) and tobacco cutworm (Spodoptera litura), and less pathogenic against white grub (Holotrichia serrata) larvae. This study sets the basis for establishing new biocontrol agents to be used in pest management programs in India.