Pupae

[Lyril]

I assume the maturation of butterfly pupae is governed by temperature. So early butterflies emerge from pupae that have successfully overwintered in cool, safe places.

Is it possible to duplicate this with very late pupae that will not be resuot in successful butterflies because of low temperatures? Lke the late Autumn ones? Has anyone attempted this?

I assume the commercial butterfly breeders must have some tricks like this to keep their stocks high. Any hints?

[Sarah]

Monarch pupal development is governed by temperature. Pupae that develop in warm temperatures develop faster and those in cool temperatures develop more slowly. However, there is a limit to how long you can slow down development without causing developmental problems. Monarch pupae shouldn't be kept in a refrigerator (the best way to slow development) any longer than two weeks. Any longer, and they begin to lose coloration and have problems with their wings. So no, breeders do not keep their pupae somewhere cool all winter. They may put some in the fridge for a short amount of time (a few days to a week) to space out emergence, but the only way to keep a monarch culture going all winter is to keep producing eggs that in turn create the next generation of adults.