Casebearers

A case-bearing leaf beetle laravae (Chrysomelidae: Cryptocephalinae)

Anyone noticing one of these small brown objects on a leaf could easily dismiss it as bird droppings.  Only a close look will reveal their secret–these cases house hungry beetle larvae, who can munch on the leaf in the security of their protection and disguise.  For my own part I only discovered these insects when I took a closer look at some of the contents of my sweep net.  They seem to be relatively common in Texas in the late spring as I turned them up frequently at a number of field sites.

These insects are a type of leaf beetle (family Chrysomelidae), belonging to the sub-family Cryptocephalinae (literally “hidden head”), the case-bearing leaf beetles, or casebearers.  (For those not up to date with Latin naming conventions, the “-dae” suffix is used to indicated families, and the “-nae” suffix is used for subfamilies.)  The ‘case’ is a gift provided by the mothers–they wrap the eggs in layers of fecal matter, which the larvae later add to.

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