Effect of Different Storage Conditions on Spore Viability of lecanicillium Lecanii formulations and Infectivity to Mealybug, Paracoccus marginatus

Talc based formulation of Lecanicillium lecanii, a native entomopathogenic fungus isolated from mealy bug was developed at Central Institute for Cotton Research, Regional Station, Coimbatore. L. lecanii spores produced in sorghum grains, sabouraud dextrose broth with Yeast extract (SDYB) and potato dextrose broth (PDB) were formulated in talc and stored at room temperature (27+2oC) and refrigerator (9+2oC). Viability and virulence of spores was monitored at monthly intervals for six months. Among different formulations tested,L. lecanii multiplied on SDY broth and formulated in talc supported maximum viability and virulence. Among two storage temperatures tested, formulation stored at 9+2oC supported maximum viability and virulence. In general, spore viability was reduced with increase in storage duration and temperature.