Sunday, May 8, 2011


I’ve always been fascinated by moth and butterfly larvae. The rush to get from egg to adult is often fast enough to satisfy even the most impatient of us. Unfortunately for me, the larvae are often hard to find. It’s always a surprise and a delight to happen upon an interesting individual, such as this larva I found in the woods on a Leatherwood shrub.

I initially made the classic mistake of misidentifying which end was the head. The enlarged posterior end certainly appeared head-like at first glance.

The side view quickly cleared things up and showed me the proper orientation. Unlike with humans, there is no right or wrong way in which a caterpillar must be positioned.

Here’s the head. It’s really quite obvious once you take a close look.

The results of a little observation make me think that this is a caterpillar out of place. A bright orange larva on a glowing green plant is much too conspicuous. A bird should have made a meal of this guy long ago. There’s also the fact that I could find no evidence of leaf damage anywhere on the plant. If this is the larva’s proper place, there should have been some chewed leaves.

I examined several Leatherwood shrubs in the area and found no evidence of feeding on any of the plants. I also found no additional orange caterpillars. I suspect that it fell out of a nearby tree and has had trouble finding its way back to the proper host plant. Possibly, it’s on a journey to locate a suitable site for pupation. Whatever it’s doing, I don’t think it has yet found the proper place to be.


  1. Looks like Xystopeplus rufago, the red-winged sallow moth caterpillar. Wagner's Caterpillars of Eastern North America notes oak as the preferred foodplant. As for the conspicuous color, he suggests it probably feeds at night and hides in foliage during the day. I should probably fill out the BugGuide page for this species.

  2. I guess he's looking for a different restaurant. :)

    It's nice to be able to check into your blog today. I've got my once-a-week US port internet connection.

    All the best from Port Canaveral, FL,

  3. I should have read the comments before I spent time looking this larva up in Wagners! It does indeed look like a Red-winged Sallow. Thanks for these photos of a -new to me - caterpillar.

  4. Thanks, Troy. I did check my copy of Wagner before posting and wondered about the Red-Winged Sallow. The prothoracic shield, anal plate and striping didn't seem to exactly match the picture or the description and I don't know enough to tell if the differences are species or developmental variation or if I'm looking at another species. I appreciate your help.

    Hi, Lois. Glad you were able to visit. I hope you're enjoying yourselves.

    Hi, Cheryl. I'm happy to show you something new. It never hurts to get in a little field guide time.