Key information
Large white butterflies have white wings with broad black tips on the forewings. Females also have two black spots and a black streak on each wing. Males have no spots on the upperside, but two black spots on the underside.
The large white is common throughout Britain and is considered a pest by many gardeners, as the caterpillars can severely damage Brassica crops. Migrants from continental Europe join our resident population each summer. Females lay clusters of 40-100 yellowish eggs on the undersides of leaves.
The caterpillars, which are grey-green mottled with black spots and yellow stripes, hatch after a few weeks. They feed communally, making large holes in the foodplant’s leaves. They protect themselves from predators by accumulating mustard oil, from the foodplant, in their bodies – this makes them smell unpleasant and extremely distasteful.
The caterpillars pupate beneath eaves, under fences or on tree trunks: it is often easy to find the overwintering speckled chrysalises, from which adult butterflies emerge in spring.
What they eat:
Adults drink nectar from flowers. Caterpillars eat Brassicas, such as cabbage, kale, and Brussel sprouts, and nasturtiums.