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Entomology (Study of Bugs)/What is this? It flew into my office this morning . . .


This flew into my office
This flew into my offi  
QUESTION: Sorry to intrude on you like this and ask what may seem like a silly question.

But, this flew into my office this morning ...what is it??

It's huge! Sounds like a fly….largest one I've ever seen here.

I live in Azusa, Ca…that's in the San Gabriel Valley area East Foothills.

Just making sure it isn't something that we/I need to be alarmed about.

Thanks for your time in advance,


ANSWER: Dear Rick - It is indeed a fly, but exactly what kind has me a bit puzzled at the moment. Not many flies have a proboscis shaped like the one in you image; among the most commonly encountered ones are bee flies (family Bombyliidae), but these usually are smallish to medium-sized flies - see for some examples. I assume that your specimen no longer is available for examination, so I can only suggest that should you encounter it or a similar specimen again, that you try to obtain a photo from directly over it so that all the wing veins can be seen. This would greatly facilitate identification.
Sorry not to be able to tell you more,

---------- FOLLOW-UP ----------

QUESTION: FYI . . . I sent my question to others as well. Here is what Lynn Kimsey said.

Not to worry. Its large but just a flower fly. These flies feed on flowers (that's why they have the long mouthparts) and the larvae are predators on aphids and things like that.

Lynn Kimsey
Professor of Entomology

ANSWER: Dear Rick - Not to doubt Lynn Kimsey's observation, but from what I could see, the proboscis on your specimen looked more to me like one that was permanently extended (as in bee flies) rather than flexible/extendible as in flower/hover flies. This why I would like to see the wing veins in your specimen, the venation in the wings of syrphid flies is very distinctive, and immediately separates them from other families. Did Prof. Kimsey provide any image(s) that could be compared with yours? I am always willing to be proven wrong; the older I get, the less I know for certain!

---------- FOLLOW-UP ----------

QUESTION: I have the perp in question and have taken several Hi Res pictures, I don't believe this system will allow for many hi res photos to be sent at once. Is there a better way to get them to you??



Dear Rick - As I hesitate to provide my email address in this forum, is their any way that you could upload them to a service such as Flickr or Photobucket and then let me know the link? Failing that, if you can attach just one image that clearly shows the wing veins in a follow-up question, that should suffice for my purposes.
Waiting to hear back,

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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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