Hyalophora cecropia overwinter question

Unlikely. I think it usually takes about 90 days of cold weather, and being spun up at the end of June isn't all that

unusual, it depends on the conditions the larva were in- temperature, food plant quality, one time I sold some Hyalophora

euryalus ova to a buyer in California, he raised his larva indoors, while I had mine sleeved outside, here on the central

Oregon coast in the USA, a warm day in summer is mid 60's f, and the nights are cool, at any rate, he sent me pictures of mature

larva while mine were still in L3 at best, his larva had matured in 40 days, and that would have been mid July.

Not Hyalophora, and I'm just making an "educated" guess at 90 days, I think speaking with other breeders have

given me that impression. Some Saturniidae and Sphinx , along with some butterflies are multi-brooded,

Antherea polyphemus, Actias luna, a number of Sphinx species,

The pupa would begin to darken, and sometimes it's possible to see the adult forming inside a pupa or chrysalis,

pupa are often very lively , I've had Actias luna cocoons move all over a cage floor, and some respond to moisture,

I've got some Manduca rustica pupa that wiggle every time I mist them. If you were sure you had food plant,

one could manipulate the life cycle, perhaps you might break the diapause in a shorter time, but animals can also

be affected by the length of daylight, that's part of many species development, and something you might want to be aware

of if rearing during the winter, I've raised tropical Actias like isis and maenas during the winter and use lights to replicate

an equatorial day cycle.