Friday, July 27, 2012

Tussock Moth Meets Mate

Kevin Firth is one of our Butterfly House wranglers and a skilled amateur entomologist, by which I mean he knows a whole lot more about insects that I do but still has a day job to pay for his hobby.  He shares some of his finds with us and I am passing this one on.  

White-Marked Tussock larva
Back on June 30 I collected a couple of Orgyia leucostigma (White-Marked Tussock) larvae on a trip to Bois D'Arc CA.  One of those larvae now resides in the house after spending time at the Caterpillar Petting Zoo on Saturday's Butterfly Festival.  The other one had already pupated.  

Wingless female tussock moth
Tussocks utilize the hairs that cover the larvae as part of the cocoon, which might help to deter predators that don't want hair in their meal (you can see them in the photos).  As I was getting ready to go to bed last night, I checked the cage that the cocoon was in and noticed something sitting on the cocoon.  Sure enough, the adult Tussock had eclosed.  It was a female, and in this species, the females are wingless.  Not the prettiest of moths--in fact, the female is essentially a sack full of eggs.

Male Tussock found his mate
I knew from prior experience with this species that if I put her outside, she would call in some males by releasing a pheromone.  So I found a piece of wood and placed her (and the cocoon) in the bark and went to bed.  Sure enough, when I got up and checked on her this morning, a male had found her.

When I got home from work, the male was ready to move on, so I released him.  The female, meantime, had laid her eggs on the cocoon (that's why I left her with the cocoon) and covered them with a foam-like substance(the white stuff at the bottom of the cocoon).
Female below cocoon
Small brown thing is mom!



You'll notice that she is considerably smaller in these pictures (you would be too after delivering several centa-tuplets!). So now we'll wait for the eggs to hatch, and then we'll have a bunch of larvae for the house.

The Moth Madness photo exhibit by Dr. Chris Barnhart will be at the Springfield Conservation Nature Center on August 1.  Fifty spectacular artistic photographs and your Master Naturalist logowear (or any other type of clothing) gets you in free.  What a deal!!

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