Distribution and diversity of native entomogenous nematodes in Poplar based agroforestry

Abstract

The identification of native insect associated nematodes that are adapted to local climatic condition is essential for the insect pest control in forestry, agroforestry and agriculture. To find out the distribution and diversity of EPNs and parasitic nematodes, soil samples were collected from Poplar growing regions of Northern provinces of India. The nematodes were isolated from collected soil samples using larvae of greater wax moth, Galleria mellonella. Entomogenous nematodes were recovered from 7.92% soil samples. The nematode species were identified by DNA barcoding procedure using D2/D3 expanse of 28S rDNA region. Out of the recovered nematode samples 78.9% were from Rhabditidae and 21.0% were from Cephalobidae family. A total six nematode species were recovered. Among these, three species namely Metarhabditis rainai, Metarhabditis amsacte and Oscheius myriophilus were facultative EPNs, two species namely Acrobeloides saeedi and Distolabrellus veechi were insect parasitic and one Mesorhabditis sp. was insect phoretic nematode. Diversity indices such as Simpson, Shannon- Weiner, Pielou’s and Margalef’s index were calculated and result revealed that the species richness was the same in all the three states under study, with four species recorded in each state. The obtained native facultative EPNs viz. M. rainai, M. amsacte and O. myriophilus and insect parasitic nematode A. saeedi and D. veechi may be considered as potential bio-control agent against various insect pest in forestry, agroforestry and agriculture. However, field trials are required to validate their effectiveness in the location of their occurrence in the present case.