|Metarhizium acridum is the new name given to a group of fungal isolates that are known to be virulent and specific to Acrididea. Previously, this species has had variety status in Metarhizium anisopliae (var. acridum) and before that, reference was made to M. flavoviride.
M. acridum almost exclusively infects grasshoppers in the suborder Caelifera of the Orthoptera. Various research groups, including the international LUBILOSA Programme (which developed the product 'Green Muscle', based on M. acridum isolate IMI 330189) have identified and addressed key technical challenges for exploitation of microbial control agents including: isolate selection, mass production and delivery systems (formulation and application). In other words, insect control (mortality) depends on factors like the number of spores applied against the insect host, the formulation and weather conditions. Oil-based formulations allow the application of fungal spores under dry conditions, and are compatible with existing Ultra-Low Volume (ULV) application techniques for locust control.