back to HYPP Zoology home page


.

Small white butterfly, Common cabbage worm

Description, Biology, Life Cycle, Damage, Common Names, Images

[R]Biology
- Host plants: essentially Brassicae, nasturtium (Tropoeolum).
- Adult: the butterfly is essentially diurnal. It mates towards mid-day; the couples then flutter around for an hour or two.
- Egg: deposited singly on the underside of the leaves of wild brassicas and of cabbages.
- Caterpillar: gnaws the epidermis of the leaves and pupate on the host plant (*) .

[R]Life Cycle
- Two generations per year.
- The butterflies having overwintered as pupae appear in spring and lay eggs mainly on the wild brassicas. This generation is rarely harmful. The caterpillars pupate and the butterflies which result deposit their eggs on cabbages in June. The caterpillars pupate in August-September and overwinter.

[R]Damage
- The damage is due to the second generation and can sometimes be important. The caterpillars sometimes leave only the main veins of the leaves. Their frass accumulates in the central part of the cabbage causing its decomposition accompanied by a nauseating smell.
- Unlike cabbage moth (Mamestra brassicae) larvae which attack the leaves of the heart of the plant, those of the small white butterfly attack the open leaves (*) .

[R] Images

1. Pieris rapae (L.) Adulte at rest (Coutin R. / OPIE)
   
2. Pieris rapae (L.) Larva Larva resting on a cabbage leaf.
   
3. Pieris rapae (L.) Damage on a cabbage The outside leaves are shredded.
   
4. Pieris rapae (L.) pupa On a fragment of a cabbage leaf. Note the silk belt (arrowed) which supports the pupa.