Three leading entomopathogens isolated from Madagascar's migratory locust, Locusta migratoria capito Sauss, were evaluated in field and laboratory tests. In a field trial in Madagascar in 1994, two isolates of Metarhizium flavoviride Gams and Rozsypal (SP3 and SP9) and an isolate of Beauveria bassiana (Balsamo) Vuillemin (SP16) were tested against L. migratoria capito. Locusts from field plots treated with SP9 experienced 100% mortality in 8 days, a higher death rate than that found in locusts treated with M. flavoviride SP3 or B. bassiana SP16. However, locusts treated with M. flavoviride SP3 or B. bassiana SP16 had significantly higher mortality than did the untreated controls. In separate field and laboratory trials in Cape Verde in 1994, SP9 was also tested against the Senegalese grasshopper, Oedaleus senegalensis Krauss. Oedaleus senegalensis treated in small-scale field plots with SP9 experienced 100% mortality in 8 days, a significantly higher death rate than that of the untreated controls. An extensive laboratory bioassay with SP9 revealed a dose–response for rate of mortality to O. senegalensis. Results from these trials in Madagascar and Cape Verde suggest that one or more of the Malagasy strains evaluated have good potential for biocontrol of locusts and grasshoppers.