Pathogenicity of Bacillus subtilis Against Symbiotic Fungus of Euwallacea fornicates (Coleoptera: Scolytidae) From South India

Abstract

In India, the shot‐hole borer, Euwallacea fornicates, commonly known as the tea borer, infests the galleries of tea plant twigs under natural conditions and is a major pest of tea. The current investigation focuses on the antagonistic ability of Bacillus subtilis to directly inhibit the growth of plant pathogens in two different climatic regions of tea‐growing area. The evaluation reveals that (a) B. subtilis can directly suppress the growth of plant pathogens (b) in the in vitro evaluation; the B. subtilis suppressed the growth of the Fusarium ambrossium, which is the nourishment for the ambrosia beetle, (c) it also revealed that the antagonistic microbes and the entomopathogens are able to control the pest population of the shot hole borer of tea. The impact of B. subtilis on mycelial growth, sporulation, and spore germination of F. ambrosium in agar medium was observed. In the field condition on the post‐treatment assessments shows an average decline of 40% in both foliar and soil drenching. Hence, we recommend the antagonistic bacterium B. subtilis for including as an IPM for the management of shot hole borer in tea.