Abstract

S.A. BALOGUN and O.E. FAGADE

Field survey of population of Zonocerus variegatus revealed a high fungal incidence of 76% when Sporulation tests were carried out on grasshoppers cadaver. Eight fungi with differing incidence rates were isolated. These are Fusarium sp. (8%); Beauveria bassiana (18%); Metarhizium sp. (20%); Aspergillus flavus (10%); Penicillium sp. (13%) Aspergillus niger (14%); Mucor sp. (13%) and unidentified fungus (4%). Fungal isolates virulence bioassay response showed that B. bassiana had the highest lethal time (LT50) of 2 days. Metarhizium sp with LT50 of 5 days was selected in lieu of A. niger which does not prove to be pathogenic to grasshoppers. The results were discussed in relation to the ecology of fungal pathogens of the variegated grasshopper and their possible role in control of Z. variegatus in the agroecosystem of south west, Nigeria.