Missouri Master Naturalists- Springfield Plateau Chapter

Thursday, June 22, 2023

At Home in the Dung

On the Missouri Prairie Foundation Bioblitz, "Bug Eric" Eaton was leading an insect identification session when I found this 6mm firm lump on a leaf.  Eric identified it as a beetle egg protected by material the female beetle deposited over it. 

I cornered Doug LeDoux of the Missouri Department of Agriculture who was leading the leaf beetle walk and he gave me more information.

"It is some sort of a Chlamisine beetle in the Chrysomelidae, possibly Neochlamisus. They refer to this group as the case-bearing case makers. The case is actually poop that is deposited around the developing larva to protect it from predation and to hide it while it feeds and develops. I see these fairly often when sampling."

This may sound like child abuse but remember it is a bug eat bug world they live in.  Looking like nothing edible has survival value.  Imagine how this delicious naked larva would look to any predator.....delicious!

Neochalmisus sp - Beatriz Moisset
Now the larva lives and eats inside the case, using its own excrement to enlarge the case as it grows.  Here is how Wikipedia describes it.

"The larvae remain on the natal host plant and add to and enlarge their fecal cases as they grow. Case enlargement in Neochlamisus is an elaborate process that larvae perform regularly until the case is sealed to the substrate prior to pupation. During this stage of the life cycle, beetles are immobile and are particularly vulnerable to predation."


Neochlamisus - Wikimedia

 This is just one example of a Neochlamisus.sp. in Wikipedia.  There is a whole tribe, if not subfamily, of casebearing leaf beetles. The warty beetles are pretty tiny compared to the larval case we found. It isn't just another pretty face, but before you make judgements about its appearance, take into account its rough childhood.

This is just one of the many fascinating finds from the annual Missouri Prairie Foundation bioblitz.  You can follow MPF and join up for the fun at https://moprairie.org/.