Larder Beetle

2014 April 5

The last time I photographed a larder beetle (Dermestes lardarius) was way back in September of 2007, and it’s time to get up some better-quality pictures, I think. So, here’s one that we found inside the light fixture in Rosie’s room.

There were three of them in the light (two were dead). I don’t know if they were attracted by the light, or if they were feeding on the corpses of the flies and gnats that had been attracted by the light.

Here’s a close up that shows the segmented, clubbed antennae.

Larder beetles are more commonly found in garbage cans, compost heaps, and food storage areas. They are about twice the size of the related carpet beetles (which are also in the family Dermestidae), and seem to like their food a bit moister than carpet beetles do. In my experience, having a lot of larder beetles around is an indication that something is rotting somewhere, while the carpet beetles are just an indication that there is hair or dander around for them to eat. In general, I think that clearing out larder beetles is easier than clearing out carpet beetles, as it is easier to find out where they are breeding and get rid of it.

And just to show that not every tiny beetle you find in the house is a dermestid, here’s a little beetle (about 3 mm long) that Sam found on the living-room floor. It was kind of dusty, and pretty fast, so the pictures aren’t the best, but from the shape it looks to me like one of the smaller species in the family Carabidae.

It has the general shape of a carabid beetle (which are mostly predatory), and from this blurry picture of its head it looks like it has predatory-type mandibles.

Of course, there are an estimated 2,430 known species of carabids in North America, and given the generally not-too-great quality of the pictures I might not be able to get it narrowed down much further than this.

3 Responses leave one →
  1. April 5, 2014

    At what point in time do you think that they realize that hanging out in the light fixture might not have been a good idea? You’d think there would be some kind of thermostat sensor in their tiny brains where they avoid heat above a certain temperature.

  2. April 6, 2014

    I think their big problem is that, the way the light fixture is designed, it is relatively easy for an insect to get in, but hard for them to figure out how to escape again. Especially since the likely exit points would require getting closer to the hot light bulb, which is presumably what they are trying to get away from.

    Since people mostly don’t want bugs in their light fixtures, I wonder if there would be a market for “bugless” fixtures that are specifically designed so that insects can and will leave when it starts getting too warm for them?

  3. April 8, 2014

    How about a bug-sized hole at the bottom? Still, I’m not sure how many people would want to buy bug-saving light fixtures. Besides you and me, I mean.

    :-)

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