Polyphemus Moth

Perhaps you may recall the photo of the wild silkworm cocoon that was posted back in April. I was becoming a little discouraged at the lack of activity and wondered if we should place the cocoon, which was housed in a terrarium and protected from the sun by our shaded porch, into full sun. My worries were for nothing because during the heat wave Thursday, sometime in the mid-morning hours, a gorgeous female Polyphemus Moth (Antheraea polyphemus) emerged from her cocoon.

Female Polyphemus Moth (Antheraea polyphemus)

The Polyphemus Moth is so named because of the giant eyespots ringed with yellow, blue, and black on the hindwings. In Greek mythology Polyphemus is the one-eyed Cyclopes and son of Poseidon and Thoosa; the name means “much spoken of” or “famous.”

The Polyphemus Moth has also transparent spots on the forewings. Antheraea polyphemus is one of North America’s largest moths with a wingspan of four to six inches. Like the Luna Moth and Cecropia Moth, the Polyphemus Moth belongs to the Giant Silkworm Family or Saturniidae.

Male Polyphemus Moth (Antheraea polyphemus). Note the comb-like feathery antennae of the male, which are nearly double the size of the female. The large antennae can more easily detect pheromones released by the female. 

I was hoping a female would emerge, knowing that she would release pheromones, which would attract a male. Thursday night we set up the terrarium outside in a sheltered area around back. The following morning, sure enough, I discovered a perfect male specimen clinging to the back door. They don’t fly very well when their wings are not warmed sufficiently so he was easy to capture. I placed him into the terrarium with the female. Her abdomen is bursting with eggs and she had already begun to deposit unfertilized eggs everywhere—on leaves, her old cocoon, and the glass walls of the terrarium. That night I woke up every hour on the hour to try to photograph their mating, but I don’t think a pairing took place.

Female Polyphemus Moth with abdomen swollen with eggs.

She is continuing to deposit eggs each evening. Her abdomen is still quite swollen. I am keeping my hopes up that they will get it together so the male will fertilize her eggs and we can then rear the caterpillars! Both male and female emerge without mouthparts; they do all their eating in the caterpillar stage.

Polyphemus Moth Cocoon found on White Birch  (Betula papyrifera) April 1, 2012.

Update on Giant Silk Moth Cocoon

No exciting news yet to report on our Giant Silk Moth Cocoon. The leaves of the American Birch Tree are unfurling, but no movement within the cocoon.

Giant Silk Moth Cocoon

I am so excited to tell you about this wonderful find. I was walking my pooch Rosie on our usual route down to the harbor and, dangling at eye level from a tree that I have passed a hundred times this winter , there was this structure. Thinking it was what it is, I ran home and checked my Lepidoptera books, and it is the cocoon of a member of the Giant Silk Moth Family, Saturniidaee (not to be confused with the oriental silk moth, Bombyx mori, from which silk fabric is spun).

 Hanging from the tip of the American White Birch branch you could easily mistake it for a dry withered leaf, and that is exactly what the caterpillar has done, weaving the leaf around itself to pupate within. The cocoon is quite a good size, approximately two inches in length by one inch in width. The caterpillar pupates during the summer, overwinters in the cocoon stage, then emerges sometime in May or June. Giant Silk Moths live only for about a week. They mate soon after eclosing and then perish. Giant Silk Moths do not have mouth parts; all eating is done during the caterpillar stage.

Giant Silk Moth Cocoon

Several members of the Giant Silk Moth family of caterpillars eat birch leaves.  I am hoping (and it looks a great deal like) it is the cocoon of the simply stunning Luna Moth, however it could also be the beautiful Polyphemus Moth.

Luna Moth ~ Images courtesy Google

Polyphemus Moth ~ Image courtesy wiki