Small Red Beetle from Decaying Stump

2012 September 12

There is a small wooded patch just behind our house that has a number of decaying chokecherry stumps. On April 19, 2012, we decided to tear apart one of the stumps that had practically turned to powder to see what (if anything) was living inside. And one of the things we found was this little beetle with bright-red wing covers.

I think the thing next to it is a fly pupa, which I left in the photo just to provide a sense of scale (I don’t know what kind of fly it might have been, because it never emerged, but it would have been something a bit bigger than a housefly). The beetle and the fly pupa had no particular connection, other than being found in the same crumbling stump.

Based on obvious features like the size, coloration, and structure of the antennae, this sure looks like Zenodosus sanguineas[1], one of the “Checkered Beetles”. The red coloration runs all around the abdomen, although on the underside it isn’t quite as bright as the wing covers.

The head just looks typically beetle-like.

These are predatory, so it wasn’t in the stump to eat the dead wood, but rather to eat the other things that were eating the dead wood. They are commonly found under bark that is infested with bark beetles, merrily devouring the other larvae. They come out during the day, and since that red color is pretty eye-catching, I would bet that they have pretty good chemical defenses and taste really foul.

[1] “sanguineas” means “blood-red”, so this comes up in a lot of species names for red-colored insects. And “sanguine”, meaning “cheerfully optimistic, hopeful, or confident”, originally meant “full of blood”. I guess the idea was that when people feel scared or doomed, they tend to get pale, so not being pale was a sign that one felt things were going well.

One Response
  1. September 13, 2012

    although this beetle seems to be
    a jewel of its kind
    that might grace a shoulder
    or dazzle an onlooker— blind

    I must admit that close up
    the red pull of its cape
    was insufficient to prevent
    a shudder at its shape

    the segmented pins of legs
    that groped for purchase on a hand
    somehow made the creepy crawly
    hard to view and understand

    I wish to be less squeamish
    about the bugs you display
    but the red wing covers of the beetle
    did not persuade me to stay

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