What is this? - Ask Extension
A friend of mine sent me the attached picture and asked me what it was. I am from NM and the pic was taken on a farm near Boulder, CO. Can someone...
Knowledgebase
What is this? #158927
Asked October 29, 2013, 5:40 PM EDT
A friend of mine sent me the attached picture and asked me what it was. I am from NM and the pic was taken on a farm near Boulder, CO. Can someone tell me what these are? They appear to be insects or exoskeletons.
Boulder County Colorado
Expert Response
Those are the old cases (exoskeletons) that surrounded the pupa of some beetle.
It is difficult to tell which one it might be - information on the substrate specific site would be useful. First guess is that it is the pleasing fungus beetle http://bspm.agsci.colostate.edu/files/2013/03/Pleasing-Fungus-Beetle.pdf These develop on the fungi of rotting logs.
Some leaf beetles, notably those on cottonwoods and willows, produce pupae such as this. But they almost always pupate on the leaes or twigs of the host plant, which does not appear to be the case here.
Netwinged beetles are also a possibility, which would pupate under a board or log. Not all that common a beetle in Boulder County, however. More common further east on the plains.
It is difficult to tell which one it might be - information on the substrate specific site would be useful. First guess is that it is the pleasing fungus beetle http://bspm.agsci.colostate.edu/files/2013/03/Pleasing-Fungus-Beetle.pdf These develop on the fungi of rotting logs.
Some leaf beetles, notably those on cottonwoods and willows, produce pupae such as this. But they almost always pupate on the leaes or twigs of the host plant, which does not appear to be the case here.
Netwinged beetles are also a possibility, which would pupate under a board or log. Not all that common a beetle in Boulder County, however. More common further east on the plains.
I do believe it is the pleasing fungus beetle. The exoskeleton, time of year, and habitat all point to it. Thank you for your help!!
