between six and nine centimeters
more or less continuously when kept warm,
Not difficult, but some experience is required. Keep in spacious, well ventilated plastic containers. Their preferred food plants drie rather quickly when cut and placed in a netted cage which is not beneficial for a good growth. In plastic containers this is less problematic. Watch out for condensation and do not give wet leaves. Fast growing and ready to pupate in approximately six to seven weeks . A living room temperature is enough. The pupal stage is short when kept warm (approximately 3 weeks).
preventing them from emerging very late in the season when there are no food plants left