Beauverla bassiana (Bals.) Vulll., upto the fourth sub-culture and Metarhizium anisopliae (Metsch.) Sorokln var. anisopliae upto the third sub-culture recorded significantly higher biomass, mycelial growth, conidial count and viable conidia. However, subsequent sub-culturing of these mycopathoaens showed significant reduction in all these biometric characteristics at various sub-cultures. Mortality data of worker (major) caste of Odontotermes brunneus (Hagen), with different sub-cultures showed significantly higher mortalities upto the fourth sub-culture in B. bassiana and till the third sub-culture in M. anisopliae. The same trend was reflected in case of LT50 values in both the fungi. However, the virulence of these two mycopathogens was restored when the fungi were passed through their host viz., termites just once. Subsequent two passages through the termites, did not markedly improve the virulence.