Virulence of Entomopathogenic Fungus Metarhizium Anisopliae (Metsch.) Sorokin on Seven Insect Pests

In-vitro bioassay was conducted to evaluate the bioefficacy of Metarhizium anisopliae (Metsch.) Sorokin (Deuteromycotina: Hyphomycetes) against seven common insect pests of Tamil Nadu, India viz., Dysdercus cingulatus (Fab.) (Hemiptera: Pyrrhocoridae), Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae), Aphis craccivora (Koch) (Homoptera: Aphididae), Mylabris pustulata (Thunb.) (Coleoptera: Meloidae), Pericallia ricini Fab. (Lepidoptera: Arctiidae), Spodoptera litura (Fab.) and Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) by dermal toxicity tests. LC₅₀ value was ranged from 1.62 x 10⁴ to 1.75 x 10⁶ spores/ml. Results revealed that among the young ones tested, the lowest and highest LC₅₀ values were recorded for P. ricini II instar (1.62x10⁴) and H. armigera III instar (1.75 x10⁶), respectively. Among the adults, A. craccivora recorded lowest LC₅₀ (1.84 x 10⁴), followed by O. hyalinipennis, D. cingulatus and M. pustulata. Thus the results show that M. anisopliae can be used for the control of H. armigera.