Metarhizium anisopliae is a mitosporic entomopathogenic fungus that has been exploited extensively as a biological control agent (BCA) against several pests. Metarhizium anisopliae var. acridum, is much more host-specific than Beauveria, affecting just grasshoppers and their close relatives. Jaronski's lab has found that Metarhizium is very infectious in most American grasshoppers & the Mormon cricket, which also causes destructive outbreaks. Metarizhium spores infect locusts by literally boring into their cuticle. Once inside they use up water & nutrients and grow tiny tubes which eventually kill the insect. Early attempts to produce a water-based spray failed & Dr Milner's team spent years developing a mix of vegetable and mineral oils in which Metarhizium spores can be delivered with maximum efficiency. In an oil suspension, Metarhizium can be sprayed under very hot conditions and won't dry out.The product does not persist in the environment for more than two to four weeks.