Entomology (Study of Bugs)/Infested chipmunk


Bugs in question
Bugs in question  
Hello! I live in New Brunswick, Canada. My cat recently brought home a 'gift' for the family. As I removed the still warm chipmunk from our front mat (with gloved hands), I noticed it had two large cyst-like lumps on it, and one seeping hole. Beside the poor creature rested a live bug I had never seen before. The two lumps on the chipmunk contained other bugs of the same variety. Can you please identify these for us? I've owned cats for as long as I have lived here and they have brought our family many gifts, but never have I seen these bugs, or anything like them before. Any help would be much appreciated!

Dear Cyndi - These are larvae (maggots) of a rodent bot fly (Diptera: Oestridae) in the genus Cuterebra; likely the tree squirrel bot fly, Cuterebra emasculator. They develop under the skin of their host, breathing through a hole they make in the host's skin. When they complete their development, they squeeze out through that breathing hole to find a safe place to undergo pupation. The adult fly lacks functional mouthparts and cannot feed. See http://tinyurl.com/nfwu5lq for more detailed information.

Hope this helps,

Entomology (Study of Bugs)

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Ed Saugstad


Will accept most questions in general entomology, including those related to medical entomology, taxonomy, ecology, arthropod surveillance, and pest management. If you are requesting a 'mystery bug' identification, PLEASE either attach an image to your question, or post an image on a web page (such as Flickr) so that I can look at it, as verbal descriptions frequently are insufficient for a definitive identification.


21 years in the U.S. Army as a medical entomologist; duties varied from surveillance of pest populations (including mosquitoes, cockroaches, ticks, and stored products pests) to conducting research on mosquito-virus ecological relationships and mosquito faunal studies. Ten years as a civilian analyst for the Department of Defense, primarily on distribution of vector-borne diseases worldwide. Limited experience on surveillance of agricultural insects in North Dakota and Indiana.

Entomological Society of America, West Virginia Entomological Society, Society for Vector Ecology, National Speleological Society, West Virginia Association for Cave Studies.

American Journal of Public Health, Contributions of the American Entomological Institute, Japanese Journal of Sanitary Zoology, Journal of Economic Entomology, Mosquito News, and Mosquito Systematics.

B.S. in entomology from North Dakota State University in 1963, M.S. in entomology from Purdue University in 1967.

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