The Io moth & caterpillar- some amazing natural designs
On a nature walk this morning at Stump Pass State Park in Englewood, FL, our group came across two caterpillars of the Io moth (see photo). At this stage they are a striking light green, with a red and white stripe along their sides. The younger caterpillars are brown to orange-brown. Although we were tempted to pick this beautiful green caterpillar up, I knew that this species has poisonous spines that can cause a lot of pain. One might assume that the green coloration is for camouflage, although it is so bright that it might even be considered a warning coloration along with the red/white stripes. The branched, poison-bearing spines pack a powerful jolt to any potential predator.
Strangely enough it was about three years ago that I saw the adult of this strange moth at our farm in Galax, VA. The unusually colored adult moth appeared on a window screen one morning where it must have been drawn to the lights the night before (see photos). With the wings closed the moth is cryptic in the right background and would presumably escape detection by most predatory birds. If it is detected and is poked, it opens its wings and reveals a marvelous set of false eye spots (see photo). Many moths have eye spots on their hind-wings that mimic an owl's face or just provide something scary for a bird to think about. But the Io moth has what I consider the most impressive set of eye spots. But even so I am amused that a bird would find this intimidating.
One again we can be amazed by the evolutionary process that can lead to the development of such a remarkable pattern. The variety of animal coloration is a never ending source of wonder.
Bill Dunson
Englewood, FL & Galax, VA
Lava reaching skyward
This past Sunday, a group of us Charlottesville folk went to Humpback rocks up on the Blue Ridge (mile 5.8 on the Blue Ridge Parkway). We enjoy being within a twenty minute drive of these higher elevations...and we aren't alone. The parking lot was packed, and the nearby by living farm exhibit gets year around attention. The trip up there is always amazing because the landscape changes so dramatically before ones eyes...and your ears "pop". Interstate 64 climbs diagonally up the mountain cutting through thick deposits of metamorphosed lava. We were time travelers ...traveling forward in time to see denuded trees that will dominate our view down on the Piedmont in a couple of weeks; our trees are still hanging on to leaves...especially the oaks, hickories, and invasives (pawlonia, white mulberry, etc.). We were also traveling through
a complex geologic landscape, ultimately ending up in meta-basalts deposited when central Virginia was well south of the equator, and turned 90 degrees east!
We all met at the parking lot, the kids poured out, and off we went into a woods known for its high black bear population. Some estimates claim that 3 bear live upon every 2 square miles of woods....that's quite a bit. The nearby Shenandoah National Park boasts the largest population of black bears in the east. This is not the time of year to see them though...late spring and early summer is when you can catch them moving about as mating season kicks in.
An immediate thing noticed when one looks up from the parking lot is that a strenuous hike is about to be had. The hike covers over 1000 feet of elevation in less than a mile...with some mild rock climbing thrown in there. Half our kids had to be carried. The others had something else in mind....a race to the top!
We moved up the mountain, over outcroppings of 570 million year old Greenstone (young for Blue Ridge Rocks!). These rocks are old lava flows that once covered great amounts of what are today Virginia and Maryland. The rock is hard, very hard, and thus resists erosion. This greenstone holds up most of the peaks and ridges for most of the way thirteen miles south and over a hundred miles to the north.
The forest was dominated by
,
, and Hickory(
,
, and
).
,
, and
were the dominant understory trees. A few old field relics were scattered about in the forest, including large Flowering Dogwoods and Black Locusts, which were probably the oldest trees we saw at Humpback.
One of the familiar and signifying attributes of the dying black locusts is the polypore it plays host to, the
. So far as I know, it only grows on the Black Locust!
Along the trail we occasionally encountered enormous Chestnut Oaks. Check out the size of the one John's leaning on! Also notice the very distinct bark of the Chestnut oak...so deeply furrowed.
We also found several witchhazel in late bloom (see image with the inset), all but a few had dropped their long and wispy yellow petals and stamens, leaving behind these curved sepals.
All adults and kids (all five under the age of 5) made it to the top! I've tried this on two other occasions, without luck. Must have been somethin in the air! The view was magnificent.
