Subject: Whose pupal cases (?)
Geographic location of the bug: southern Colorado, ponderosa pine forest
Time: 06:41 PM EDT
Last spring I cut and split some ponderosa pine firewood in the woods behind my house. Some pieces sat up there all summer, and when I brought them down this fall, I discovered these pupal cases (?) on one chunk. I was curious to know what made them.
(Resending because my images might have been too large last time)
How you want your letter signed: Chas
These are the exuviae or cast off exoskeletons of the pupae of Fungus Beetles, probably Gibbifer californicus. Here is a similar image from BugGuide. According to BugGuide: “Larvae feed on wood-destroying fungi” and “female lays eggs in bark crevices of fallen rotting logs.”
Dear Daniel Marlos,
Fascinating! thanks a lot — now I know where to go for further research.
It was a standing, dead beetle-killed pine, so decay had already started in
some places on the trunk.
Chas S. Cllifton