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Entomology (Study of Bugs)/Need help identifying tiny round dark bug


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Hi Ed,

I live in an apartment in Brooklyn, NY and about two months ago we discovered we had a minor infestation of bed bugs. We had the whole apartment sprayed and bombed several times over and no one has reported getting bitten in over 3 weeks. This morning I noticed a tiny, round dark reddish/brown bug on my bedroom floor, though it was already dead. I've done a lot of research looking up images of bed bugs and it really didn't strike me as a baby bed bug since it was very round rather than long. It obviously COULD just be another dead bed bug but it sort of looks like a spider beetle to me. I took some photos of it placed next to a penny for scale. What do you think?


Dear Layla - This is a spider beetle (Coleoptera: Ptinidae); likely a smooth spider beetle,  Gibbium aequinoctiale - see for an image and for more detailed information on spider beetles in general, including some control recommendations.

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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