Evaluation of Different Mass Production Techniques to Enhance the Progeny of Isolated Indigenous Entomopathogenic Nematodes from Indian Himalayan Region

Abstract

The use of indigenous entomopathogenic nematodes (EPNs) as biological control agent can provide the best way for overall insect pest management in lieu of environmental stability with their wide range of benefits and less side-effect on other organisms. The identification and mass culturing are pivotal for field applications of these beneficial nematodes. The EPNs population can serve as a limiting factor in the biopesticides formulation and field spray application. This study was formulated to curb out the limitation of low population of entomopathogenic nematodes in the soil using the in vivo and in vitro mass production techniques. An indigenous strain of genus Heterorhabditis was isolated from Solan district of Himachal Pradesh and then mass cultured in the laboratory. In in vivo technique, larvae of Galleria mellonella Linnaeus (greater wax moth) and Corcyra cephalonica Stainton (rice moth) were used as bait insects in modified method of white trap and as a result, a greater number of infective juvenile (IJs) were recovered of IJs were 3 days in modified WM (1–2 million population ranges) and the maximum progeny production within the range of 2–3 million was observed on DBM with emergence time of 7 days. The present investigation suggests that the utilization of different mass production techniques can curb the constraint of low population of EPNs from, Galleria mellonella (23100 IJs) as compared to Corcyra cephalonica (12840 IJs). The culture media, including modified dog biscuit medium (DBM), modified kabuli gram medium (KGM), black gram medium (BGM) and modified wout medium (WM) were used for the in vitro mass production of isolated nematodes. The minimum time taken for emergence of IJs were 3 days in modified WM (1–2 million population ranges) and the maximum progeny production within the range of 2–3 million was observed on DBM with emergence time of 7 days. The use of in vivo culturing was found to be best for initial isolation and small-scale mass production and greater wax moth is better bait insect in comparison to rice moth. The use of in vitro technique was helpful in mass multiplication in large number of the isolate, therefore making it convenient for field application. The present study could help in popularizing the use of entomopathogenic nematodes as biological control agents and alternative to chemical pesticides.