Metarhizium anisopliae is a naturally occurring soil fungus that infects and kills insects through direct penetration of the exoskeleton. Unlike Bt (which must be eaten), Metarhizium works on contact - fungal spores land on the insect, germinate, penetrate the cuticle, and colonize the body from the inside.
Ticks (excellent - Met52 is specifically registered for tick control), termites, mosquito larvae, white grubs, root weevils, thrips, spittlebugs, grasshoppers, beetles. Very broad host range across many insect orders. Does NOT infect mammals, birds, fish, or plants.
Met52 EC (Novozymes/FMC - tick and ornamental pest control), BioCane (sugarcane grub control, Australia), Green Muscle (locust control, Africa), various experimental and regional products. Growing commercial availability as biocontrol gains mainstream acceptance.
Completely non-toxic to mammals, birds, fish, and plants. Cannot infect warm-blooded animals because Metarhizium cannot grow above 95F (35C) - mammalian body temperature kills the fungus. Safe around children, pets, and wildlife. OMRI organic approved.
For ticks: Met52 applied to lawn borders, woodland edges, and leaf litter can reduce tick populations by 50-75% in treated areas. The fungal spores persist in the leaf litter and infect questing ticks on contact. Multiple applications per season recommended.
How infection works: Spores land on the insect cuticle. Within 24 hours, they germinate and produce an enzyme (chitinase) that dissolves through the exoskeleton. The fungus enters the body cavity, multiplies, produces destruxin toxins, and kills the insect in 3-7 days. The insect then becomes covered in green spores, which can infect other nearby insects.
Environmental persistence: Unlike chemical pesticides that degrade, Metarhizium persists and reproduces in the soil ecosystem. A single application can provide weeks to months of ongoing control as the fungus cycles through pest populations.