Looper

I was passing a group of small Redbuds growing in a sheltered place beside the garage, when I noticed a triangle shape in the foliage.  The sight of a shape not naturally produced by growing stems caused me to stop and examine more closely.  I found this looper type caterpillar apparently beginning a journey up a leaf stem.  It doesn’t matter how well you mimic a twig, if you put yourself into an untwig-like position.

The caterpillar possesses a remarkable camouflage.  Body form, color, pattern and texture all match components of the actual twig.

The two conical projections on the head help to identify this as a Cleft-headed Looper, the larval stage of the Pepper-and-Salt Moth.  The projections remind me of terminal buds and play a part in the twig mimicry.

Located behind the head are three pairs of legs.  Caterpillars sometimes appear to have many legs, but these six are the only true legs.

At the other end of the body are leg-like structures known as prolegs which are short, hook tipped appendages used for gripping.  It’s not uncommon to hear a tearing sound as the ends of the prolegs are pulled from the substrate, especially if you are removing caterpillars from your clothing.  The hooks work in the same manner as those found in Velcro.

Looper caterpillars lack prolegs in the center portion of their bodies.  They travel in typical inchworm fashion by extending the body until the front legs get a firm grip and then bringing forward the rear end by arching the body into a loop.

Hopefully, this fellow got where he was going without attracting any predator attention to his triangle pattern.  It would be best if it just stopped forming these abnormal shapes.  Of course, this species is in the family Geometridae, so it’s to be expected that this guy would know a little something about Geometry.

Parasitized Looper

Plant eating larvae are often difficult to find because of their habit of blending inconspicuously into the plant upon which they feed. Camouflage can be a detriment when the larva finds itself on the wrong part of the plant. I was investigating holes in the leaves of a Tuliptree when this twig mimicking looper fell from above and landed on a leaf. If it had refrained from moving, it probably would have passed as a small twig fallen from the tree. Its first reaction, though, was to strike out in search of a more secure location.

Some people refer to these moth larvae as inch-worms because their form of locomotion resembles a method of measuring by using a length of flexible material. I prefer to call them loopers because of the loop formed by the body each time the tail end scoots up to meet the head. Regardless of the name, they’re a fascinating animal to observe.

This one seems to be carrying a bit of an extra burden. On its back is a balloon-like cluster of parasitic larvae and below that seems to be a cluster of eggs. There also appears to be a scattering of eggs just behind the head. For those who haven’t yet gotten their bearings, the head is to the left.

It’s hard to tell just what stage of development the larger cluster is displaying. If those are larvae that will hatch to invade the looper’s body, there won’t be much room left inside for anything else. I’m not familiar with parasites that feed from the outside of the body. They could be larvae that have exited the body in order to pupate. It just seems to me that the looper doesn’t have enough body mass to accommodate all of the offspring that will exit those eggs.

In any event, I imagine that this guy has just about formed his last loop. It might be that he is already weakened and that contributed to his fall from the tree. It’s certain that he won’t live to transform into an adult moth. The question is whether or not he can survive long enough to nurture a couple broods of parasite larvae.

Sycamore on the Prairie

Sycamores are trees of river banks and lowland fields where moisture is plentiful. So why is there a Sycamore growing on a dry south facing slope surrounded by xeric prairie plants? This is definitely a tree out of place. It’s growing well now, but whatever water supply it has tapped into cannot be plentiful enough to allow the tree to grow to any great size.

Lack of water is not the only problem this tree faces. The base of the trunk is trying to recover from an extensive deer rub. This tree was lucky it only lost half its bark. Some bucks are so aggressive that they shred the trunk and tear off the top of the tree.

Even though the tree is only ten feet tall, the bark is being shed in typical Sycamore style.

The top portion of the tree is scarred by Periodical Cicada egg laying activities. Some spots have healed over while others are oozing like a festering sore. This won’t help the tree’s chances of long term survival.

Sycamore has one of my favorite leaf shapes. The large lobed leaf has broadly scalloped edges with big teeth. Shaded leaves are often the largest of any species in the woods.

The base of the petiole is greatly enlarged where it attaches to the stem. The enlargement serves to protect the new bud, which won’t be exposed until the leaf falls for the winter.

Now that I’m not specifically looking for caterpillars, I’m once again finding them everywhere. This looper was racing around the edge of the Sycamore leaf, but I couldn’t find where it had been feeding.

While I was moving branches to get a leaf in good position for a shot, this walking stick crawled out onto my arm. This specimen is much stouter than the one I posted before. Perhaps this is a female.