Memoirs of the Entonological Society of Canada l7l: 265-286 (1991) Four research programmes are investigating the entomopathogenic fungal genera Metat hiziunt and Beauveria for locust and grasshopper control in Africa. ln the LUBILOSA programme, surveys for pathogen isolates revealed a morphologically distinctive Metarhizium t'lavoviride Gams and Rozsypal attacking acridoids in West Africa, Madagascar, and elsewhere. Metarhizium anisopliae (Metschnikoff) Sorokin isolates with virulence to acridoids were also obtained, including several from non-orthopteran hosts. Natural epizootics ofboth genera are rare in acridoid populations, but do occur. A standardized screening method discriminated virulent from non-vitulent isolates. The great majority of the most virulent isolates were from the acridoid group of M . JIat,oviride. A Niger isolate chosen for development from this group had 1ow virulence to honey bees and parasitic Hymenoptera and was not infective to insects in several otler orders. Field tests were carried out on fo^rmulations of oil mixtures, using ULV application rates of l-2Llha and2-5 x l0'' conidia per hectare. In preliminary tests, target insects were sprayed successfully in small field arenas and in large cages. Trials