GMG FOB Ben’s Newly Emerged Giant Polyphemus Moth!

20140323_193347Joey forwarded an email from reader Benjamin, who asks the following,

“I found a silky green worm last August. I put it on my house plant and the next day it had turned into a caccoon. It has been in my house for almost 8 months. It came out on my birthday March 22. So how do I attract a male for my moth? It is the biggest one I have seen.”

Hi Benjamin,

Thanks so much for writing. You have a gorgeous Polyphemus Moth (Antheraea polyphemus), and it does look like a female in the photo provided as they have thinner antennae than the male.

On the evening of the day the female emerges, she releases a pheromone, which attracts the male. Mating occurs that evening to early morning. After mating, she immediately begins to deposit eggs on the leaves of her caterpillar’s host plant.

Polyphemus Moths are members of the Saturn Family of moths and they emerge only to mate and deposit eggs of the next generation. They do not drink nectar because they do not have mouthparts.

You don’t say in what state you are located so I will provide you with two responses.

If you live in our region, it is far too early for the moth to have emerged and therefore, far too cold to place outdoors to attract a male. She will die if placed outdoors at this time of year.

If you live in a warm climate where there may be male Polyphemus moths on the wing, I have had success with placing a female in an enclosed screened porch entryway. When I wake up in the morning, I often find a male waiting outside the porch door. He’s usually easy to capture. Then I place him in the enclosed area with the female. Hopefully–no guarantees–mating will occur.

If in the future you are so lucky as to find a Saturn moth cocoon, or a caterpillar that pupates and turns into a cocoon or chrysalis, I highly recommend leaving it outdoors in a sheltered spot where you can locate it the following spring. Indoor temperatures are usually much too warm and will trick the moth into emerging too soon. I keep all chrysalisides and cocoons in a terrarium on my front porch (not the enclosed area), where they can experience normal winter and spring temperatures and humidity, and will therefore emerge at the appropriate time of year.

Polyphemus moth caterpillars eat a wide variety trees including willow (Salix), maple (Acer), birch (Betula), and oak (Quercus). Saturn Moths are in sharp decline, largely because of all the terrible herbicides and pesticides people spray on trees, which kill not only bad bugs, but all species of adult Lepidoptera, and their cocoons and chrysalides as well.

Polyphemus Moth Antheraea polyphemus cocoon
Polyphemus Moth Cocoon ©Kim Smith 2012

Polyphemus Moth

Perhaps you may recall the photo of the wild silkworm cocoon 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 also has a pair of 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 tree (Betula papyrifera) April 1, 2012.