A female Orange Tip with its mottled green underwings just visible,  was sampling nectar from Garlic Mustard flowers .   (Extra)   Nearby another was ready to accept the attentions of a male who had to chase off a rival.  Once mated, the females find suitable plants on which to lay their eggs, usually just one to a plant. Once the female has laid an egg on the plant, she leaves a pheromone which deters other females from laying there. The usual food plants for the Orange Tip are Cuckoo Flower (or Lady’s Smock) Cardamine pratensis and Garlic Mustard Alliaria petiolata (also known as Jack-by-the-Hedge). There is normally not enough edible material to sustain more than one caterpillar per plant so the larvae are cannibalistic, eating other eggs or larvae on ‘their’ plant.  Young larvae start by consuming the flower petals and end up eating the developing seed pods before it is time to pupate …..   before emerging as a butterfly the following spring.