Hi Roger. The ground around the area with these fungi was littered with pupal casings when we first found it some weeks ago. Hopefully, lots of successful moth emergences. Tim
Possibly 15 to 20%. For every fungus we saw above the ground in this area there would have been around 5 pupal cases. However, the fungi were growing in an area of sandy soil with leaf litter off to the side of a path. Many of the pupal cases were scattered around this area, including on the path. Not all were within it. I guess the fungus mycelium (?) within the ground doesn't yet extend much beyond this patch of ground where the fungi are appearing above the surface.
My guess is that, in a parasite such as this (with a fairly specific host preference), the mycelium would be confined to the host. If so, we'd be seeing the results of independent infections here.
Correct Heino, the mycelium is confined to the larva that is originally infected by swallowing a Dreichmeria spore on the vegetation when it comes to the surface to feed at night