Excerpts from Jim Conrad's
from the June 13, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
MATING DEAD-LEAF MOTHS
Sometimes the most interesting discoveries are made in the most unexpected places. That was the case one morning as I was returning a wheelbarrow to its place at the shop, passing some large plastic drums holding chemicals. At first I thought that somehow a brown leaf had gotten stuck to the drums but then I wiped the sweat from eyes, drew closer, and saw what's shown above.
Bea in Ontario tells me that those are mating Dead-leaf Moths, DYSDAEMONIA BOREAS, members of the big, flashy Saturniidae Moth Family. They're good-sized critters, with wingspans of about 5-3/8 inches (13.7 cm). I was fascinated by the holes in the wings and the way the bottom one's back wings curl down. Bea points out, though, that several species in that family do the same thing, some even more spectacularly.
Judging from the large number of pictures of this moth on the Internet, Dead-leaf Moths must be fairly common throughout their distribution, which is from Mexico to the Guyanas in South America.
I left the moths in the picture alone but I was interested in the remarks of one fellow who had photographed the species in Central America. He said that when he touched his resting moth it fell in a slow, zigzag pattern, just like a falling leaf.
Could that be why the hind wings are curled, to cause the falling moth to zigzag like a falling leaf?