Saturday, October 23, 2010

Buck Moth!

About this time of year, when the foliage turns color and leaves begin to fall, and temperatures plummet, one of our most extraordinary moths begins to fly. By now, most leps - butterflies and moths - are spent, their numbers and diversity way down from summer's peak.

A recent foray into Shawnee State Forest with John Howard and Janet Creamer - meeting up with Dave Riepenhoff in the forest - had a primary objective: Buck Moth!

An unseasonably warm day did bring out plenty of late season butterflies, soon to give their last gasps. This lovely dove-gray critter is a Gray Hairstreak, Strymon melinus, sipping nectar from our most common aster, White Heath Aster, Symphyotrichum pilosum.

We were fortunate indeed to stumble into a Red-banded Hairstreak, Calycopis cecrops, looking remarkably fresh for this late in the game.

But this was our primary target: Buck Moth, Hemileuca maia. Once you've seen one of these pied brutes, you'll want to see another. We saw several dozen today, but in general I don't think Buck Moths are very common nor widespread in Ohio. Mostly it's the males one sees; rapidly fluttering through the forest, hot on the pheromone trail of a girl. When they do pause, it's normally on the trunk of a tree.

Buck Moths come out late. Here in Ohio, they probably just starting flying a week ago, and they'll continue to remain active until well into November and the first true freezes and plummeting temperatures. It is said that their common names stems from the fact that the adults fly when the buck White-tailed Deer begin to rut.

A female Buck Moth perches on the leaves of a Black Oak, Quercus velutina. Oaks of many species are the forage of the larvae. Adult females lay rings of eggs around the twigs of oaks, an that's how they overwinter. Larvae emerge in the spring, and the caterpillars feed their way through several instars, or growth stages. As the caterpillar grows, it becomes increasingly armed with urticating - stinging - hairs, and you'd be wise not to handle one. In parts of their range in the south, where Buck Moths are far more common than up here, people dread them because of the caterpillars. Considerable effort is put into localized spraying programs to control the caterpillars.

The business end of a male Buck Moth. They are a member of the Saturniid Family - Saturn moths - and adults in this family don't eat. Adults live only to find each each other, mate, and lay eggs. And that incredible comblike antennae is how the male does it. The boys fly madly through appropriate habitat, trying to pick up the faint scent put off by the girls.

Few moths are fuzzier than a Buck Moth. This is a male, with its orange-tipped abdomen. The sheer density of "fur" on these things is remarkable, and a fantastic adaptation for a critter that has to warm itself enough to take wing on days when the temperatures don't break out of the 50's.

It's interesting how all or nearly all of our prominently black and white moths are day-flyers. Buck Moths, Grapevine Epimenis, Eight-spotted Forester, White-striped Black Moth: all share a similar basic color pattern. Hmmm... if you know why, let me know.

Anyway, I hope a Buck Moth crosses your path this fall.

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