The most beautiful gift of Nature is that it gives one pleasure to look around and try to comprehend what we see.
There is a wild cherry (Prunus serotina) sapling just outside our screen porch that is a favorite spot for all sorts of natural events. Wild cherry is a great host plant for a variety of moths and butterflies so I let this young tree grow in a spot too close to the house to ever reach any height just so I can keep track of the comings and goings of its tenants. It has been a busy place these past few days.
Throughout the year, I can always count on seeing some sign of one of the primary occupants of this species of tree, the red-spotted purple butterfly, Limenitis arthemis. They lay their eggs at the tip of cherry leaves, and the larvae feed on the leaves through their entire caterpillar and chrysalis stage, appearing as bird poop mimics. And they even overwinter on the plant, with the third instar larvae of the fall generation making tiny sleeping bags, or hibernacula, by cutting away much of a leaf and rolling the base into a hollow tube where they spend the winter. Next spring, when the cherry leaves first sprout, the tiny larvae will emerge form their tube, begin feeding on the fresh leaves, and begin the whole cycle again. In the photo above, the larvae has already attached the leaf to the twig with silk (so the leaf fragment remains on the tree all winter) and is just beginning to curl the base of the leaf with even more silk (silk strands shrink as they dry, pulling the leaf together).
By the next day, the larvae had finished constructing its hibernaculum and was resting inside. I’m a bit surprised it has constructed this so soon as there is still plenty of time for it to grow, pupate, and start another generation before cold weather. But, there are not many leaves left on this tree at this point, so maybe caterpillars can take a cue from food availability and go ahead and go into a resting phase for the winter.
On a nearby cherry sapling, I found a much larger red-spotted purple larva which will soon, no doubt, form a chrysalis.
Back at the original tree, there were a couple of other caterpillars to observe. One of my favorite finds this time of year is the white-marked tussock moth caterpillar, Orgyia leucostigma . They remind me of a combination caterpillar and toothbrush, due to the four prominent tufts protruding near the head, plus the two black-colored tufts of setae out front that resemble some fancy flossing tool.
Nearby was another one that had just molted. This species is a generalist feeder, so I find it on a variety of plant species around the yard.
Nearby was another of my favorites, an early instar of the unicorn caterpillar, Schizura unicornis. These guys do an amazing job of blending in with the edges of the leaves of whatever they are feeding on. As I looked around, I found a few more…and that will be some fodder for my next post.
That red-spotted purple caterpillar looks like bird poop. Are they one of the known caterpillars to mimic bird poop?
Yes, it is one that actually is a bird poop mimic throughout it’s larval stages and even in the chrysalis.