Are imperial flying in Midwest now???

[lday at iquest.net]

HELP.... does anyone know when imperial moths begin to be on the wing
here in Indianapolis?  (Midwestern USA).   

I have a huge fat female who needs a mate, but I fear she has hatched too
early.  She's outside in a cage right now, but I'm not optimistic.  
Is it too early for wild males?

THANK YOU (I'm not looking forward to getting up at 4:45 am tomorrow
to go rescue any males from the birds, so don't want to keep this up
if it's hopeless)

Liz Day
LDAY at iquest.net 
Indianapolis, Indiana, central USA, 40 N latitude, zone 5.