Subject: Unknown Caterpillar
Location: Palominas, AZ, Cochise County
September 26, 2016 4:15 pm
This caterpillar was found on a Mesquite tree in Palominas, Arizona, Cochise County, on or around September 24, 2016, by Jessica Ray. She requested that I submit her photos for identification.
This is definitely a Lappet Moth Caterpillar in the family Lasiocampidae, but we cannot say for certain which species or even definitively which genus. According to a posting entitled Living Illusions on the Lappet Moth Phyllodesma americana on the Beautiful Nightmares blog: “The caterpillars munch on leaves by night, hiding on twigs and bark by day. They are also well-hidden, but because they have to be able to live on a variety of different trees, each of which has a differently-colored bark, lappet caterpillars don’t have a color that matches a particular background. Instead they, like their parent moths, have bodies with distorted outlines, specifically a lateral fringe of long hairs. On bark, this helps a caterpillar “merge” with the bark on which it rests. … Animals that depend on camouflage have to stay very still to avoid detection, but if they are spotted, staying still quickly becomes futile. Many animals use color to startle predators as a backup plan, the best-known example being the red-eyed tree frog. At rest, the frogs appear a solid leafy-green, but if disturbed, they quickly open their eyes. The sudden appearance of two giant, bright red eyes can be enough to startle a predator, which might give the frog time enough to make a hasty escape.” Discover Life has images that support that might be a correct species identification, however, based on this BugGuide image, we would not rule out that it might be in the genus Tolype. At any rate, your marvelous images clearly depict both the camouflage and the flash of warning colors.
Thank you Daniel for identifying the Lappet moth caterpillar. I searched high and low trying to identify it myself and finally gave up. Again, many thanks.