Field evaluation of native white grub bio-agent, Bacillus cereus strain WGPSB-2 in Uttarakhand Himalayas and its impact on soil microbiota

A microbial pathogen, Bacillus cereus strain WGPSB-2 isolated from mid hills of Uttarakhand Himalayas (1000-1500 amsl) had potential as a biocontrol agent against white grubs of the region. Thus, the pathogen’s ability to suppress grubs was investigated under field conditions over a period of five years in five villages of the region. A single dose annual application of WGPSB-2 as talc based formulation (1x1010 spores/g) at the rate of 5kg/ha showed a sharp decline in grub population over the years in all the targeted villages. Pit sampling data showed maximum grub reduction during initial years of treatment in all villages and found significant for time, villages and time X village interactions in repeated measures ANOVA. Twenty four months post-inoculation resilience took place in micropits tested for bioagent impact on micro-floral densities, resulting in similar/ positive structures of tested microbial populations. The substantial numerical reduction of grub density coupled with no negative impacts on soil inhabitant microbiota, signifies WGPSB-2 as a vibrant technological option in this ecologically sensitive region.