Bot Fly Puparium

Bot Fly Puparium

5878  Last week I found one of these ‘shells’ and another this week. One was in plain site and the other was in a dark toy bin. The shell is hard and brittle and the inside has a pus like consistency, any information would be appreciated.   Thanks,  Nolan

This is a puparium of a rodent bot fly (Diptera: Oestridae; subfamily Cuterebrinae) in the genus Cuterebra. When the larvae of these flies are fully grown, they emerge from their rodent host in search of a dry place to undergo pupation – see http://tinyurl.com/zr7yx2g for images and more detailed information.  Ed Saugstad, retired entomologist; Sinks Grove, WV.