Monday, June 15, 2020

Cryptic Caterpillar



Lois Zerrer sent this photograph for identification. 
"I found it about a week ago as I was picking up sticks in the backyard after the heavy overnight storm. I picked up the branch and immediately felt something soft definitely not twig like.  What a surprise I had when I turned the twig around."
I sent the photographs on to Chris Barnhart who identified it as a noctuid larva, "probably Catocala (underwing moth)."  The caterpillars in
this genus can be round or flattened like this one.  They have lichen-like coloration on the back but some have bright colors underneath.  When approached by a predator they can twitch as seen in this video and flash the bright warning colors called startle coloration.  They then drop to the ground where they blend in and virtually disappear.

Beloved underwing - Wikipedia
There are more that 60 species of underwing moths in Missouri alone.  Their forewings are dull tan to brown, resembling tree bark.  The hind wings are usually bright orange or red and are hidden unless seen in flight.  Like the startle coloration above, this is a trick similar to goatweed leafwing butterflies, cottontail rabbits and the white flag tail of a deer.  In motion your eye follows the bright spot, then looses the animal when that color disappears.




Catocala ilia - Clark Creighton
Our friend Clark Creighton sent us this caterpillar for identification a few years ago.  It was distinctive enough to recognize as the caterpillar of the beloved underwing moth, Catocala ilia.  You can see it changing its color by flipping over in this video.