Tuesday, May 19, 2009

Living with carpet beetles

Over the past year or two, winter and summer, I have been finding the occasional carpet beetle on my walls. Mostly, I have killed the larvae, observed and photographed the adults (and blogged them), killed the survivors. (I check behind the laundry basket for larvae daily.) After all, I don't want larvae in my sweaters and books.

But I had questions; how do the adults get here? How do they survive; what are they living on? How long do they live, and where, when it's freezing outside? How often do they breed? How long do the larvae live in our closets before they pupate; where are those pupae, and what do they look like? How long are they in this stage?

Most of the books and websites I found were focussed on discussions of control methods; how to eradicate carpet beetle larvae from your home and lab. Information about life cycle, especially the adult stage, was scant and brief.

Carpet beetle, in the wild.

When, with the advent of warmer weather, carpet beetle adults started showing up here more regularly, I found a glass container with a good lid (an old butter dish), and started keeping them alive on my desk.

"Pet" carpet beetles, on flower petals.

They live for at least a week with no food available. I give them a drop of water every couple of days. In a couple of websites, I read that they eat flower pollen. One named the flowers: daisies, asters, spirea.

Hmmm. The daisies and asters aren't out yet, and there are no spirea near my place; what have they been eating before they decided to pay me a visit? I've been treating them to the small flowers from my garden. They like maple flowers, dead nettle, apple blossoms; they seem to ignore violets and pansies. And they live longer than before.

They sleep often; sometimes I think one is dead. I have learned to mark its position. Hours later, when I check, it's "dead" somewhere else. They don't try to escape; their walls are glass, and they don't climb them. And their wings are used mostly for helping them flip back on their feet after they take a tumble. They don't try to fly out when I take off the lid to observe them. (Other beetles aren't so cooperative.) Awake, they trundle about, nibbling at the flowers, occasionally stopping to sip at a droplet of water.

Carpet beetle in captivity, on apple blossom stem.

How about breeding? They lay their eggs in sheltered locations; under baseboards, in crevices in the woodwork, and so on. I gave my "pets" an inch-square piece of coloured paper for a hiding place. That should provide the illusion of shelter and the eggs will stand out on the paper.

I can't tell which is male and which female, but once I had four or five live adults in the container, I figured there would be at least one couple. I kept a close watch on them, and caught a pair in the act:

Love in the springtime.

And there are eggs on the underside of the paper! In a couple of weeks they should be hatching. I'm planning the nursery already; a tightly-lidded, double-sealed container made cozy with old wool scraps. Maybe I should give them a stuffed Teddy bear.



  1. While the rest of us are trying to evict the little so-and-sos, you're setting up carpet beetle love nests and day care centres! You will have to start charging them fees.

    Look forward to reading about their development. There are so many interesting critters hanging around the house and garden.

  2. Hee Hee..
    I am going through your posts..because have missed so many..I was wondering what my buggy blogger was up too..
    hee hee..she has carpet beetles as pets and will have a nursery for them..
    she is one funny gal..
    I think shes great...she makes me smile.

  3. Snail; "love nests". :-D

    Nina; you will! I'm thinking pink and green wool, with stimulating touches of red.

    Dawn; Carpet beetles, spiders, pill bugs and truncated worms ... I'm glad you're smiling!

  4. Random question do they lay eggs year round or mostly just in the warmer months?

  5. The common carpet beetle may have as many as 4 generations in one year, although they may take anywhere from two months to over a year.

    This batch of eggs didn't hatch; I'll try again next cycle.

  6. Anonymous6:23 am

    Do you have a picture of the eggs? It would be helpful to see!

  7. Anonymous, No, I don't. I've forgotten why.
    Next time, I'll get one.

  8. I am amazed at how they live without any water. I have cleaned all carpets in the house, but in my office behind my huge desk where I could not reach and have computers blowing hot air, there seems to be more nests of them. I guess they like the warmth, but where in the world are they getting water to live? You can only eat dust and dead skin fragments for so long. I am quite puzzled how the larvae keep coming up in the carpets, and living without water. Do you have any ideas?

  9. gamestacker; I don't know. Maybe there's a hint of moisture in the wood walls, or even in the air. I've kept them for a couple of weeks without water (forgot) and most of them died.

  10. Thanks! You're a super blogger.

  11. Anonymous12:48 pm

    the larva that is in my room and can't get rid of is destroying my skin...it looks like cat scratches on my back and stomach and bites that are all over and so itchy that I am bleeding...this is the information that I have been searching for...is there a lotion that could be put on that they don't like...have you tested anything like that yet...I am at my wits end...thank you...

    1. Sorry; carpet beetle larvae don't bite. You must have something else.

  12. I really dont like carpet beetles. They cause serious damage to fabrics, carpets, furs, stored food, and preserved specimens. That is why i always call carpet cleaning at hills once a two month.


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