This experiment was conducted at Insect Pathology laboratory, Department of Entomology and Central Instrumentation, PJTSAU, Rajendranagar, Hyderabad in order to study the cellular immune response of Spodoptera litura (Fabricius) to the entomopathogenic fungus Metarhizium anisopliae. It would be a cumbersome work to collect the data on hourly basis. Moreover working on the haemolymph and its characteristics of an insect is a very exquisite work. One of the most prevalent and pervasive entomopathogens, M. anisopliae is recognised to be a highly effective bioagent for the control of insects of several orders. A fungal suspension containing 2.03×108 spores ml-1 was applied to larvae in their third instar. Following inoculation, hemolymph samples from treated and untreated larvae were collected at 1, 3, 6, 12, 24, 48, and 72 hours. Plamatocytes (PLs) and Granulocytes (GRs) were found to be the major haemocytes involved in the immune responses of the lepidopteran insects. Total Haemocyte Count (THC), PLs, GRs, Phagocytosis and Nodulation were observed as a part of cellular immune response. The THC, PLs, GRs, Phagocytosis and Nodulation were increased up to 24 HAI and later decreased. Despite these insect defence mechanisms, fungal hyphae development was seen after 72 HAI, which finally caused the host to perish.

Spodoptera litura, Metarhizium anisopliae, Cellular Immune Response, Total Haemocyte Count (THC), Plamatocytes (PLs), Granulocytes (GRs), Phagocytosis and Nodulation

It was observed that when S. litura larvae were treated with the fungal suspension the immune response was increased up to 24 HAI and later decreased. The immune response was high in fungi treated larvae up to specific period of time when compared with the control (Tween 80). Despite these insect defence mechanisms, fungal hyphae development was seen after 72 HAI, which finally caused the host to death.

Adama Thanuja, S.J. Rahman, P. Rajanikanth and Bharati N. Bhat (2023). Cellular Immune Response of Spodoptera litura (Fabricius) to the Potential Entomopathogenic Fungus Metarhizium anisopliae (Metschinkoff) Sorokin. Biological Forum – An International Journal, 15(7): 11-17.