Anthrenus sp. carpet beetle
Urbana, Illinois

Little Anthrenus beetles are one of the most common insects across the northern hemisphere. Adults can be found in flowers feasting on pollen, and the detritivorous larvae are often inhabitants of homes and buildings. If you’d like to see one of these yourself, check your window sills- there’s a good chance a few will have accumulated around the edges as they try to exit.

A few years ago I attended an organizational meeting for the great Beetle Tree of Life project. A couple dozen of the world’s greatest Coleopterists were crammed into a room in Bozeman, Montana, hammering out which species to include in the project and assessing who could supply fresh specimens.

Could we find the elusive South American Tetraphalerus? Yes! The Argentinians had some.

How about the only-seen-in-Japan-and-Siberia-a-few-times Declinia? Yes! We could get that rarity too.

And Anthrenus, the ubiquitous carpet beetle?


Then, laughter. In a room full of beetle collectors, no one had even a single specimen.

An insect can be so common that experienced entomologists just pass it by. Anthrenus is one of these. Not worth the effort to pull out a vial and collect it. We’d have been better off with a group of less discerning Entomology 101 students.


photo details:
Canon EOS 50D camera
Canon MP-E 65mm 1-5x macro lens
ISO 100, f/13, 1/250sec


  1. #1 Ted C. MacRae
    May 7, 2010

    I’m laughing uproariously at this – I have been finding these guys in significant numbers along my window sills of late and have been gathering them up and disposing of them. Now, pondering whether I actually have any in my collection, I really don’t think so.

    I’ll fix that tonight 🙂

  2. #2 Tim Eisele
    May 7, 2010

    And yet, I’ve been finding that non-entomologists are *deeply* interested in these – although not in a good way. A couple of years ago, I put up some pictures of a carpet beetle larva. Since then, that page has accumulated over 300 comments, with commenters being active as recently as today. Commenters are mostly people who want desperately to kill them, but are not having much luck. One of the regular commenters referred to that page as a “carpet beetle support group” a while back, and I suppose that’s what it is.

  3. #3 DrA
    May 7, 2010

    Oh look, that nice rosaceous flower has a bug on it.

  4. #4 Susannah
    May 7, 2010

    I love these beetles, whether or not they eat my sweaters. (Sometimes they do.)

    I’m laughing about Tim’s 300 comments on the beetle; I’m still getting visitors from a link on the companion post, Carpet Beetle Adult. No comments, though. But every single day there is at least one visitor from other sources, too, (today there were 3, so far) looking for carpet beetles.

    Funny about the commenters; as Tim says, most are asking how to kill them. Very few people actually see the beauty of the little critter. Their loss.

  5. #5 notedscholar
    May 7, 2010

    We should take all of the common insects and mine them for medical benefits. How lucky if one of them was useful!

    Otherwise, is entomology just driven by a desire for rarity?


  6. #6 MarekB
    May 8, 2010

    Hmmm, looks like the ubiquitous Anthrenus verbasci that is also the most common pest feeding (at least trying to!) on my mounted ants:
    I didn’t know it is found in NA as well, but some reading reveals it is a cosmopolitan species.

  7. #7 Dave Stone
    May 8, 2010

    I always find it interesting that very few of my field biology students end up with either a housefly or mosquito in their collection. I think they just assume houseflies and mosquitoes will always be there when they need them. The first big frost is always traumatic…

  8. #8 Dr. Migolowich
    May 9, 2010


    Your comments are interesting. Us entomologists are always worrying about rare insects because, as you so eloquently put it, we are driven by a “desire for rarity”. Medical entomology is thus far a largely untapped field, and I too await the day when the comment genera (e.g. Anthrenus), are juiced for the benefit of mankind.

    That being said, there is no issue with our “desire for rarity”, for it is often in the more mysterious, darker tunnels in the hive of life where major medicinal advancement is made.

    Dr. M

  9. #9 Joy K.
    May 19, 2010

    The last picture makes the beetle appear to be fuzzy. Is it? I’ve never (knowingly) encountered one.

  10. #10 josh
    February 24, 2012

    I have a picture of this exact same species of flower (or, well, it appears to be anyway) from the C-U area, which I didn’t notice until I got home had a carpet beetle in it.

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