Sunday, August 29, 2010

Polyphemus moth

A few weeks ago, I made a trip over to the famous West Jefferson McDonald's. Famous, that is, among the moth-seeking crowd. While those who covet french fries and Big Macs obviously frequent the place, there is a regular contingent who make visits after nightfall, looking for jumbo fliers.

Located right along the banks of Little Darby Creek, there is scads of good habitat in close proximity to this particular Golden Arches. Couple that with the brilliant high-mounted lights that bathe the parking lot in bluish illumination after dark, and you've got a veritable pot at the end of the rainbow for those who want to find the nighttime lepidoptera.

The West Jeff Mickey D's really draws the giant moths: a variety of sphinxes, Lunas, Royal Walnut Moth, Imperial Moth, and many more. There is even a record for the gargantuan Black Witch, a rare wanderer from the tropics. Late June through July seem a bit better for numbers and diversity, but I did manage one noteworthy bruiser of a moth on this visit.

Polyphemus moth, Antheraea polyphemus.

That hand offers a size-scale - this is one big moth! Note the eye spots peeking out, and fully exposed in the first photo. The moth uses them as a defense system. If some predator stumbles into it when at rest, the moth quickly flashes its forewings to the open position. Eek! Suddenly a giant pair of frightening eyes flash in the chickadee's face, sending it packing tail between legs.

I think they should rename this particular store "McMoth's". The famous arches glare in the background; we picked the moth up off the asphalt right about where this photo was made. Polyphemus moths are probably not all that rare, but like many of the large moths they are certainly on the decline. Even though their caterpillars can utilize a wide variety of tree species for food, habitat fragmentation, among other reasons, is certainly not helping their lot in life.

When at rest during the day in a normal habitat, the moth can look remarkably like a hanging dead leaf. But they don't have to worry about avoiding predators for very long; they're probably lucky to last for a week.

Face to face with a Polyphemus. The caterpillars, which get quite large, are voracious eating machines. Allegedly one of these bags of goo can eat some 86,000 times its original weight before it transforms.

The adults do not eat at all, and have no functional mouthparts. They live only to find the opposite sex, mate, and in the female's case, lay eggs. Female moths emit powerful pheremones, which the male senses through his large fernlike antennae. Apparently the boys can sniff out the girls from a mile or more, and steer unerringly towards them in the quest to reproduce.

An adult Polyphemus is a true miracle. Probably only a tiny percentage of all of the eggs laid by a female ever make it to adulthood. The threats are many, and the caterpillars are delicacies for all manner of parasitoid wasps and flies, and hungry birds, beetles, mammals and many others.

I saw firsthand the all too common fate of a caterpillar of another species of large moth recently, and will share that sometime soon.


Scott said...

Now I've got to start driving over into town at night. I already have the neighbors convinced I'm crazy shooting pictures at night in my backyard now I'm going to have to go into town and do the same. I actually took a picture of one of the Polyphemus moth caterpillars not to far from there last year.

Cathy said...

I love it!

The moth, the information AND the golden arches.

A round egg on a plain bagel in the morning before heading to the park to search for bugs.

Life is good.

PS. Annie Dillard's chapter on the Polyphemus moth is truly painful. "Pilgrim at Tinker Creek"

Jim McCormac said...

Yes, nothing like combining a bit of mothing with the golden arches!


Anonymous said...

There is one on my front porch now! Very cool !! Grove City

dawn said...

My 7-year-old son found one of these today. I googled to find a picture to match his amazing find, and found this lovely blog of yours. Truly, this moth felt like a "true miracle" to him. I'd never seen anything like it either, at least not alive and moving about in the world instead of under a piece of glass :)

Jim McCormac said...

Hi Dawn,

I'm glad you found my blog, and that it proved useful to you. Stop back!


Mahz said...

Thank you so much for posting this info. I found two on my window mating today and I have never seen a moth that big and hairy. So I decided to find out more about it. You blog was very helpful! :)

Wendalena said...

My daughter and I found a male at The Flume Gorge in New Hampshire yesterday. We spent 15 minutes with it from the time we found it looking like an orange fungus cover leave to it "running" on the bridge chasing me! I was completely fascinated. You blog was one of the most helpful resources. After reading about it's life span I feel all tingly!