Caterpillars are consumed by everything from wasps, birds, and even people. It’s in their best interest to conceal themselves from potential predators. Three caterpillars that do their best at making themselves invisible are acitve now. All are moth larvae. If you know their language, where and when to look for them, they can be spotted fairly easily.
The first, the Common Pug (Eupithecia miserulata) can be found on herbaceous flowers growing along the pathways in Catch the Wind. We’ve seen the pug before, on daisies.
This small caterpillar (about 15 mm) seems to change color according to its diet. It’s often the same color as the flower that it’s consuming, making it more difficult to see by, say, a hungry bird.
Another small caterpillar which blends in well with its environment is the Camouflaged Looper (Synchlora sp.).
This half-pint caterpillar (aprrox. 10 mm) uses a different strategy for concealing itself than does the pug above. It chews off pieces of the flower or plant that it’s feeding on and attaches the pieces to its back. It matches the color and texture of whatever flower it happens to be on at the time, adjusting itself to the situation.
The looper pictured above, after having been photographed, crawled down from the flower it had been on and moved to another flower on the same plant.
The next day I noticed that the caterpillar was sporting a brown and yellow outfit!
Why had this caterpillar waited to apply the yellow petals to itself until it moved to this particular flower?
There are many other examples of how this caterpillar adorns itself at BugGuide.net, I think it’s worth a visit.
The third caterpillar in this group, another tiny specimen (about 10-12 mm), is the Redbud Leaf Folder (Fascista cercerisella). This prison-striped moth larva uses a most obvious method of concealment, it makes a fold in a redbub leaf and seals it with silk to hold it together while it consumes the leaf from within. They may also overlap two leaves, attaching them with silk, but the folded-leaf method is the classic leaf folder tactic.
The problem with the leaf-folding strategy is that the leaf is very easy to spot by naturalists, and other critters, who are looking for Redbud Leaf Folders. The caterpillars may as well spell out on the leaf in big, bold silken letters, “OPEN ME, THERE’S A CATERPILLAR INSIDE!”
The trees that have leaf folders on them usually have many leaf folders on them and a bird could have a feast moving from leaf to leaf. However, I’ve discovered that the leaf folder has another strategy for eluding predators. Upon being uncovered the caterpillars often wriggle frantically, sliding off the leaf to the ground and the safety of the leaf litter below.
Falling to the ground may seem like a death sentence for a tiny caterpillar like the leaf folder who relies upon the leaves of the redbud as food, but since these little caterpillars pupate in the leaf litter beneath the trees, supposedly, after the leaf they have been munching on dries and falls to the ground, they may look at their escape to the ground as an early retirement and pupate ahead of schedule. Perhaps only the larvae that are ready to pupate wriggle off of the leaf (a research project for a biology student or a summer camper?).
I’m not so sure about how and when they pupate though. Although some references state that the caterpillars fall to the ground with the leaves in which they conceal themselves, I’ve opened many a fold and have found only silk and frass (poop) within. The empty folds lead me to believe that the larvae drop off the leaves when they’re ready to pupate and do not necessarily wait for a ride to the ground within the folded leaves, if indeed they do pupate on the ground, which does seem likely.
Now that you know what to look for and where to look, go out and have a scout around. Don’t be discouraged if you don’t find any pugs or loopers, they’re not that easy to spot. You should, however, be able to pick out the leaf folders with little or no problem!