Definitions

irroration

Large White

The Large White, also called Cabbage Butterfly or Cabbage White (Pieris brassicae), is a butterfly in the family Pieridae. This butterfly is called the Large Cabbage White in India.

Appearance, behaviour and distribution

The Large White is common throughout Europe, North Africa and Asia to the Himalayas often in agricultural areas, meadows and parkland. It is a strong flier and the British population is reinforced in most years by migrations from the continent. Scattered reports of the Large White from the northeastern United States (New York, Rhode Island and Maine) over the past century are of a dubious nature and indicate either accidental transport or intentional release. Such introductions threaten to establish this agricultural pest in North America.

The wings are white, with black tips on the forewings of both males and females, the female also has two black spots on each forewing. The underside is a pale greenish and serves as excellent camouflage when at rest. The black markings are generally darker in the summer brood. Its wingspan is 5 to 6.5 cm.

Lifecycle and foodplants

The female lays batches of 20 to 100 yellow eggs on plants in the cabbage family and can be a pest on food crops. They seem to have a preference for cultivated varieties of Brassica oleracea such as cabbage and brussels sprouts. The caterpillars are yellowish green with yellow lines and black spots and feed in groups in plain view on the leaf surface. They gain protection from predators by possessing distasteful chemicals. It has once been reported that these chemicals were mustard oils from glucosinolates in the foodplants, but this appears to be a myth since Pieris caterpillars actually suppress the formation of mustard oils (see glucosinolate). Despite their chemical defence, large numbers are sometimes lost to the parasitic wasps such as Apanteles glomeratus, whose females attack clusters of newly hatched caterpillars. The chrysalis is also yellowish green with black spots. The species over-winters as a chrysalis. It has two broods in a year, the first is on the wing in May and June and the second in August.

Adult

See glossary for terms used
The upperside of the male is creamy white. Fore wing is irrorated with black scales at base and along costa for a short distance; apex and termen above vein 2 more or less broadly black, the inner margin of the black area with a regular even curve; in one or two specimens a small longitudinally narrow black spot in interspace 3. Hind wing : uniform, irrorated with black scales at base, a large black subcostal spot before the apex, and in a few specimens indications of black scaling on the termen anteriorly. Underside, fore wing : white, slightly irrorated with black scales at base of cell and along costa, apex light ochraceous brown; a large black spot in outer half of interspace 1, and another quadrate black spot at base of interspace 3. Hind wing: light ochraceous brown closely irrorated with minute black scales ; the subcostal black spot before the apex shows through from the upperside. Antennae black, white at apex; head, thorax and abdomen black, with some white hairs ; beneath : whitish.

Female upperside similar to that of the male but the irroration of black scales at the bases of the wings more extended; the black area on apex and termen of fore wing broader, its inner margin less evenly curved ; a conspicuous large, black spot in outer half of interspace 1, and another near base of interspace 3. On the hind wing the subcostal black spot before apex much larger, more prominent. Underside: similar to that of the cf but the apex of the fore wing and the whole surface of the hind wing light ochraceous yellow, not ochraceous brown ; the black discal spots on fore wing much larger. Antennae, head, thorax and abdomen as in the male.

Similar species

Compare Small White, Pieris canidia, and Pieris deota.

References

  • Jim Asher et al The Millennium Atlas of Butterflies of Britain and Ireland Oxford University Press

See also

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