Small White

(Pieris rapae)


Habitat

There's no type of habitat where this butterfly doesn't occur.  It is extremely common and widespread and the resident population is augmented each spring and summer by migrations from abroad.  Some preference is shown for open flowery areas bordering woodland, gardens and hedgerows, wherever the butterflies can find both nectar and the cruciferous plants which feed the larvae.

Food

Cabbages and other brassica plants, and cruciferae, mignonette, horseradish, garlic mustard, radish, turnip and mustard.

Life Cycle

The pupa overwinters and there are usually three broods during a warm summer, otherwise two.  The butterflies are early to emerge, occasionally as early as February and March, but egg-laying normally starts in May.

Notes

This is a more numerous species than the Large White. The larvae of this species live singly or just a few to a plant.  Their green colouring hides them well and the damage to vegetables is surreptitious, with holes here and there, but the larvae burrow into the heads of cabbage, which the larvae of Large Whites (Pieris brassicae) do not.  The Small White selects a greater variety of foodplants than Pieris brassicae and may be found on just an odd plant, standing alone, which doesn't happen with Pieris brassicae which is gregarious and there would be insufficient food.  Pupae of the first brood are sometimes found attached to the foodplant; those of the later broods generally disperse to more hidden quarters for the winter.