Big Honking Moth
Female Cecropia Silkmoth
The largest native moth of North America is the Cecropia Silkmoth. That would be
for you purists out there. Big Honking Moth. Alarmed and awed a whole gaggle of kids this afternoon.
How big is big? Well, I have small hands, but I think this first image gives you the basic idea. To quote Wikipedia, "Females with a wingspan of 6 inches have been documented." This one is a female, which you can tell from the antennae--males have much larger and "fernier" antennae.
I want to call your attention to the resources right now, because you really must go and check at least one of them out--the one called WormSpit. A COMPLETE pictorial documentary of the life cycle of this particular moth. Outstanding, actually. You will be properly impressed!
Where we found her--freshly emerged, wings drying.
The first thing you should know about this lovely creature is that it is not a threatened species. This is not to say that populations haven't declined, because they have. I'm sure widespread use of pesticides would have an impact, as would loss of habitat and all the usual suspects. Regardless, this moth is holding on pretty well. That is probably in part because of the diversity of plants it can use as host plants--maple, birch, plum, cherry, rose, blueberry, peony, a huge batch of things from the family
, oak, sassafras, willow, dogwood, elderberry... check the University of Florida link for the best list of host plants. The dead vine to which this moth is clinging (second photo) is probably Virginia Creeper--another host plant.
So how do you go about identifying a moth/butterfly when you haven't got a clue? I started at Butterflies and Moths of North America--not because this is the definitive source of all things lepidoptera, but because it eliminates all the possibilities from other continents. After that, I made sure to select for moths, instead of butterflies. Finally, I just started perusing the photos. As soon as the first silkmoth popped up, I knew I was in the right neighborhood. The page after that, I found her. There is no mistaking that enormous, patterned abdomen for anything else!
All spread out on clematis vine
The Cecropia Silkmoth is a hardy thing--hardy enough that they use her in research. The adult has a plenty strong grip, making it easy to transport her from hazardous locations to slightly less hazardous locations. In this photo, you really see the impact of some very fine, white hair-like scales that make her appear "dusty," when the base color is a pretty dark brown. You can also see the red band at the bottom of the hind wing, and the positively hairy thoracic upper body.
Females emit pheromones to attract mates. The males detect these pheromones through the use of their antennae--which is why they get the really fancy, sensitive ones! The male Cecropia silkmoth can detect these pheromones from a mile away--but may fly many miles more than that while in search of a female.
The other physical difference besides the antennae is the abdomen--the female has a larger and rounder belly than the male. Our girl here showed hers off beautifully--that hairy belly was irresistible to the kids, once I let them know they could touch it (gently). She dwarfed most of their fingers.
Besides parasitic flies and wasps (and pesticides), the other animated local threat to these silkmoths is squirrels, who will chow down on any pupae they find. [See, they've already read that new research on how we can all add insects to our diets.] Pruning of trees can also cause some losses, as can outdoor lighting. One more reason to ditch that nearly useless security light! (For more reasons, go
For more on the development of the eggs and larvae, you should check out the links below, especially WormSpit. But before you go, here are a few more images for your viewing pleasure:
Wings getting fully extended
On dogwood, after finding information on host plants.
Below her cocoon--approximately 4 inches long.