Experimental studies to evaluate spray applications of a mycoinsecticide against the rice grasshopper, Hieroglyphus daganensis, in northern Benin

Three experiments were conducted to examine the effects of spray applications of a mycoinsecticide against the rice grasshopper, Hieroglyphus daganensis, in northern Benin. The experiments were designed to expand on previous evaluation studies and contribute to a better understanding of the overall impacts of mycoinsecticide applications. The first experiment showed that acquisition of spores from the spray residue had a significant effect on mortality rate and a greater single influence on mortality than direct contact with spores from the spray aerosol: The second and third experiments revealed the mycoinsecticide to have sub- and pre-lethal effects, causing a significant reduction in per capita feeding rate and increasing susceptibility to predation. The significance of these results for the overall impact of spray applications and for development of comprehensive evaluation methods are discussed.