Papilio nireus diapause

Hi,
Quite a few African papilio species diapause, as for how long it will last, I'm unsure, I've had some that go for 5 months before hatching out, but you might be able to force it out of diapause by raising the temperature and humidity though. Or I've heard that some papilio respond to light for coming out of diapause although i haven't tried it.

I had them overwinter in my greenhouse( in the Netherlands), just like Papilio machaon. They hatched in April and proved to be fertile.
Paul

It was unheated so just the same as outside, just no rain, snow and wind and because winters are relatively warm in the past years, amost no frost.