Microbial control of caged population of Zonocerus variegatus using Beauveria bassiana and Metarhizium sp

Microbial control of caged populations of Zonocerus variegatus was carried out using indigenous fungal entomopathogens isolated from the grasshopper's cadaver. Bioassay response indicated a dose-dependent mortality coupled with drastic reduction in food consumption among spores infected grasshoppers. Lethal time (LT sub(50)) of 4.6 days for 10 super(3) spores/ml and 3.8 days for 10 super(7) spores/ml of oil formulation of Beauveria bassiana were observed. While Metarhizium sp recorded LT sub(50) of 9.0 days and 2.8 days for 10 super(3) and 10 super(7) spores/ml, respectively. The results obtained were discussed in relation to use of the isolates in the control Z. variegatus infestation in forest agro-ecosystem of south west, Nigeria.