author(s)
Abhilisa Mudoi, Purnima Das and Lakshmi Kanta Hazarika

abstract
A laboratory experiment was conducted, to study the pathogenicity of Beauveria bassiana (KR855715) against different instars and adults of Periplaneta americana (L.) (Blattodea : Blattidae) in the Physiology Laboratory, Department of Entomology, Assam Agricultural University Jorhat-13 during 2014-2016. The study revealed its pathogenicity on both instars and adults of the insect. B. bassiana at 1x107 conidia per ml caused cent percent mortality in first and second instars at second and third days after treatment respectively. However, mortality varied from 64 -72 per cent, 52 - 68 per cent and 16 – 36 per cent mortality in 3rd, 4th and 5th instars respectively between third and ninth days after treatment. In adults mortality varied from 12 – 26 per cent between third and ninth days after treatment.