Squeaky Beetles

10 Feb
Bessbug (Passalidae) on dead wood.

Bess beetle (Passalidae) on decaying wood.

My labmate Paul brought me a box of bess beetles (family Passalidae) left over from a live insect lab.  I love these little squeakers, so I was pretty pleased.  I am not the only one who thinks the beetles are adorable.  BugGuide attributes the common name “bess beetle” to the French word baiser, “to kiss,” apparently due to the squeaky “kiss” noise these beetles make when disturbed.  This stridulation is produced by rubbing the top of the abdomen against the hind wings.  In fact, bess beetles produce at least fourteen distinct acoustic signals (Schuster 1983), giving them a pretty complex repertoire for an insect.

Less cute story:  when I was a kid, my brothers and I caught one of these for somebody’s science class.  We put it in a jar with some acetone and had to take it out again because it sounded like it was screaming.  (Anybody seen the Fly?)  Now that I’ve shared that adorable story, let me go back to talking about my awesome new pets.

A bess beetle eating moist decaying wood.

Bess beetle chewing dead wood.

Bess beetles employ a fairly elaborate vocabulary because these beetles are subsocial.  Adults excavate galleries in the dark recesses of rotting wood where they live together in family groups, cooperatively caring for their brood.  Larvae are fed pre-chewed wood by the adults.

There’s an extra twist.  Unlike termites, bess beetles don’t have endosymbionts in their guts to digest wood for them.  Instead, they process the wood and excrete it, wait for microflora to further digest the wood, and then eat it again.  (Rabbits, as ruminants, employ a similar “eat it twice” tactic.  If I have destroyed your image of bunnies, I apologize.)  Both adults and larvae starve if they are not allowed feces as part of their diet.  Yum yum!

3 Responses to “Squeaky Beetles”

  1. macromite February 11, 2012 at 4:01 pm #

    Not only are passalids great beetles, but they are monarchs of the mites. At least two dozen families of mites are found on passalids, including many that are known from nowhere else. Some are undoubtedly less than friendly, but some maybe mutualists, and others seems to use the beetles as mating platforms – one male and several females can be found on a beetle, but the juveniles live in the galleries and feed on nematodes and small arthropods. So, if you find mites on your beetles, don’t feel like you have to de-mite them.

    A bit more here:


  2. craig April 15, 2012 at 9:25 pm #

    Makes me wonder just how many organisms need poop as part of their diet. Insects yes but it is also seen in many mammals – are we missing something 😉


  1. Posts for the week « neuroecology - June 20, 2012

    […] Beetles are good parents!  And they’re social and talk! […]

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