For many years I’ve noticed colorful little caterpillars that live individually in silken retreats on the surface of leaves of poison ivy. At a recent BugGuide gathering, a photo of one of these caterpillars was shown and I realized we still didn’t know what these were. I resolved then to rear a few to try and arrive at an identification. There’s plenty of poison ivy near my home, so I didn’t anticipate much trouble finding a few.
Here’s the first one I found. The white area just behind the head is atypical. The caterpillar is smaller than usual, so it might be an early instar. It could also represent some sort of injury.
The next day I collected another one, larger.
The next weekend I collected one more.
Here’s a cropped version of the image above, showing the head. Checking these specimens and other photos on BugGuide, there appears to be quite a bit of variability in the head coloration. They all have a white band across the lower part of the head capsule though.
At that point I figured I had a good chance of successfully rearing at least one.
The last one I collected was the first to pupate. A few days before pupating it started to change color. That’s not unusual for caterpillars as they prepare to pupate. In this case it darkened to become more orange.
I neglected to photograph any of the pupae.
Earlier this month, an adult eclosed. It’s attractive and quite distinguished looking with an elaborate headdress.
After searching through various guides, I decided this must be what’s currently known as Macalla superatalis. My books actually identified it as part of a genus it was previously placed in, Epipaschia. The common name, Dimorphic Macalla (previously Dimorphic Epipaschia), refers to the fact that it comes in two color forms: green as above, or tan.
Having arrived at the identification, I checked BugGuide and found that someone had beat me to the identification based on a literature search. Oh well, it looks like I might be the first there to have successfully reared them though.
by Charles V. Covell, Jr.
by David Beadle and Seabrooke Leckie