Abstract: The virulence test of five species of entomogenous fungi Beauveria brongniartii, Beauveria bassiana, Paecilomyces fumosoroseus, Metarhizium anisopliae and Nomuraea rileyi to Spodoptera litura larvae showed that B. brongniartii and N. rileyi had evident pathogenic effects on S. litura, with the LT₅₀ value to S. litura 2nd instars being 2.95 and 4.10 days, and the corrected accumulative mortality of the instars being 100% and 95.2%, respectively. The virulence of B. brongniartii and N. rileyi to the 3rd instars was lower than that of 2nd instars. The LT₅₀ value to 3rd instars was 19.67 and 19.63 days, and the corrected accumulative mortality was 56.6% and 52.2%, respectively. Other two fungal species P.fumosoroseus and B. bassiana also had virulence to S. litura larvae. The LT₅₀ value for the 2nd instars was 4.89 and 6.34 days, and the corrected accumulative mortality reached 85.7% and 71.4%, respectively.

Key words: organic carbon, carbon and nitrogen coupling., forest soil, secondary succession, total nitrogen