It’s been unusually wet here in recent weeks, so for International Rock-Flipping Day this year I thought I’d try my luck up on the ridgetop. In the past, my style has been to flip lots of rocks and hope that I’d find something interesting sooner or later, but this year I decided instead just to find one or two especially charismatic or well-situated rocks and be content with whatever I found underneath.
After 45 minutes or so I found a rock that really appealed to me. It was up off the ground by about six inches, capping a skirt of moss-clad soil on the side of a venerable old rock oak (Quercus prinus).
The rock itself was attractive, a chunk of interestingly pitted, hard sandstone. For you geology nerds, this is right on the boundary between the Ordovician (Juniata Formation) and the Silurian (Tuscarora Formation), and is therefore about 440 million years old. This rock has been here for a while.
It commanded a great view of the Allegheny Front to the west — or at least, it will when the leaves come down. (That’s our rock in the lower left corner of the picture.)
Before flipping the rock, I got my camera ready, and made the mistake of wriggling the rock to make sure I could lift it without tearing up the moss. This unfortunately had the effect of alerting the residents that I was about to barge in — kind of like an ATF agent knocking before entering a moonshiner’s cabin.
So the principle occupant was already half-way down the entrance hall by the time I raised the roof to peek in.
Here’s a close-up. (Please excuse my tragic lack of a macro lens — an IRFD necessity, one would have thought.) Clearly, this is some kind of cricket, I’m guessing in the Gryllus or field cricket genus, 11 species of which occur in the eastern United States. But I could be entirely mistaken. Without a good picture of the entire insect, it’s impossible to tell.
One thing that’s certain, though: crickets have some very cool names. There’s the two-toothed scaly cricket, the restless bush cricket, the different-horned tree cricket, the ambitious ground cricket, the two-clawed mole cricket, the taciturn wood cricket, and the complex-trilling trig.
The underside of the cricket’s rock gave evidence of other visitors. The yellowish blob was a gypsy moth egg case — kind of an odd place for one, I thought. They’re almost always on tree bark, at least a few feet off the ground. Perhaps this was an unusually fearful or unambitious gypsy moth. I’m not sure whose eggs those are.
There were also some kind of droppings under the rock. It’s tempting to say they belong to the cricket, and a Google image search for “cricket droppings” does seem to suggest they might be. But who knows?
I scrambled fifty feet downslope and a couple million years up the geologic column to the upper portion of a talus slope, a common feature of the aforementioned Tuscarora Formation. In past years, the talus has proved an attractive but unfruitful source of good flipping rocks. I was hoping it might be different this year due to all the rain.
This rock was helpfully situated in a patch of sunlight (good for photography) but still far from the hot, dry center of the boulder field. Underneath, though, all I found was a little bit of soil and lot more rock.
Clinging to the bottom of the quartzitic slab, though, was a very cool-looking thing. This time, a Google image search was more definitive: I’m pretty sure it’s the remains of a hickory tussock moth (Lophocampa caryae) cocoon. We have the bristly white caterpillars all over the mountain, and the cocoon looks very much like some of the pictures online. The hairs on the cocoon are evidently recycled from the caterpillar:
The tiny hairs are grown by caterpillars in their final stage of development, and are transferred by the pupating larva to the outside of its spherical silken cocoon where the hairs serve as a defense against predators. The cocoons are constructed under bark of trees or objects on the ground, and can be found throughout the late summer, fall, winter, and spring months.
While I was flipping rocks, a half-mile along the ridge to the southwest my mother was checking out the seasonal pools — we tend to call them “vernal ponds” because they vanish in June and usually don’t reappear until the following March, but clearly that term doesn’t quite fit what’s there now. While gazing at the overflowing pools, Mom noticed a hickory tussock moth caterpillar that had fallen from one of the trees and landed in the water. Far from drowning, however, it was swimming — and making pretty good progress, she said. It made it all the way across the small pond while she watched.