Thursday, September 8, 2011

Brown-Hooded Owlet Caterpillar

Brown-Hooded Owlet Caterpillar - Cucullina convexipennis
A very colorful caterpillar.  It feeds on the leaves and flowers of asters and goldenrods (I've only seen it on goldenrods).  It doesn't seem particularly abundant at Westwood Hills Nature Center, where I found this one (and goldenrod is fairly abundant).  It doesn't make any attempt to hid or conceal itself, so I wonder, with its bright coloration, how it avoids predation.  Maybe the bright colors are to advertise its unpalatability to would be predators, or maybe it's faking it, hoping that the bright colors look like some kind of warning (ok, I know, its a caterpillar and it's probably not hoping for anything, just munching leaves and flowers, but maybe that's how it has evolved to avoid predation).  Or maybe it's just that a lot of them get eaten and if it could just get rid of the excessive coloration there would be a lot more Brown-Hooded Owlets around.

Whatever the case may be, it's a stunning caterpillar.  However, the adult moth it turns into after overwintering in the ground as a pupa is decidedly unstunning, and very brown.  If the caterpillar is toxic, or sends a false signal of toxicity, than as an adult it seems to switch strategies and rely on cryptic coloration to avoid being eaten.