Orange-Tip (Anthocharis cardamines)
Female left, male right.
Butterfly season begins in April here in the Netherlands. Of course you may see butterflies as early as February, but these are adult butterflies that were dormant during the winter, and became active again as the weather improved.
Butterflies overwinter in several ways, depending on the species. There are species that overwinter as eggs, others as a caterpillar, as a chrysalis (pupa), or as an adult butterfly.
In April, the first butterflies that overwinter as pupa will emerge. One such species is the orange-tip. This butterfly can only be seen for a few weeks each year. From mid April to mid May, they emerge from their pupa, mate, lay eggs and die. The caterpillars feed on cuckoo flower, garlic mustard, honesty, damask violet, and sometimes on other crucifers.
When the caterpillar is fully grown, after about 16 days, they pupate, which is just about mid-May to late June. The pupa then comes out the following spring. This butterfly lives as an egg for 5 days, 16 days as a caterpillar, more than 10 months as a chrysalis, and only a few weeks as an adult butterfly.