Done a bit of googling and found this ....
Metarhizium anisopliae
The spores attach to insects and germinate, using enzymes known as chitinases to bore through the exoskeleton
Once inside the insect, the mycelium grows and produces a host of chemicals. These include destruxins, a class of hexadepsipeptides that compromise calcium ion channel function and are immunosuppressive, and cytochalasins,
, a class of compounds that affect cell mitosis. Other compounds, still being investigated, affect protozoans living in the insects' gut that are necessary to digest cellulose. In the end, the weakened insects die as the mycelium takes over.
The dead insects look mummified with the fuzzy mycelium, and they become a launching platform for more fungal spores. In the sexual form of the fungus, a tiny club-shaped Cordyceps mushroom grows from the insect carcass. The dead insects left in a decimated colony ward off subsequent insect invasions because the carcasses remain moldy with the repellent spores.
All lifted from this article
http://pubs.acs.org/cen/science/84/8449sci5.html
HTH
Rich