Help;Polyphemus,Citheronia

[HHuf]

I live outside Detroit, Michigan. I had a female Polyphemus emerge in May. It
attracted a wild male and had a successful mating. The female was a second
brood specimen from a southern location. I am wondering if Polyphemus in double
brooded in my area. Some of the larve are in the 3rd instar. I cannot imagine
that they will pupate and overwinter. Since she called a local male I assume
the local population had started flying. I dont want to end up with a brood of
adults emerging in august. Any clues anyone? Also I have 4 Regal pupae that
have overwintered in a styrofoam box covered with 5 inches of peatmoss. I
checked them yesterday.They are alive but show no signs of emerging. The larva
were given to me last season so I dont know their proper schedule. What time
frame would be proper for emergence in my area. Is there any specific
procedures I should take?
Thanks in advance, Mark