Steve Cotterell

 Large White (Pieris brassicae)

Habitat

Woodland and open spaces. The butterfly is particularly attracted to gardens by nectar-bearing flowers and the various cruciferae which grow there.

Food

The best known foodplants are cabbage of any kind, mainly kales and cauliflowers with separate leaves rather than ball heads, and nasturtium. Other cruciferae chosen include horse radish, garlic mustard, radish, turnip and mustard.

Life Cycle

There are two, or exceptionally three, broods in the year. Pupae which have passed the winter produce butterflies as early as April and from then on butterflies will be found, as successive broods overlap, until the end of October.

Notes

One of our most prominent butterflies, the Large White is by no means the commonest British butterfly but its abundance is affected by the extent of immigration from across the Channel.  Our resident population is comparatively small.  Too much emphasis on destruction as a pest might in future years give us cause for regret.  Modern horticultural methods take care that the larvae are unable to ravage commercial crops and gardeners can likewise keep their vegetables free from serious damage.  Certainly there were once more Large Whites to be seen than there are now, even though it is still common.

The female is distinguished by the spots on the forewing: the male has only the black tips.  The extent of yellow on the underside hind-wing is very variable and in the spring brood it is a duller, greyish yellow.  Eggs are laid in clusters on the underside of the leaf.  The larvae are gregarious until the final stadium.  To pupate they wander off and attach themselves by girdle and cremaster, usually in a horizontal position, under a roof-eave, a piece of fence or some other sheltered spot.  Frequently the larvae are found at this stage covered with a mass of tiny yellow cocoons of the parasitic fly Apanteles glomeratus (Hymenoptera).