Butterflies of the World - Lifecycle, Ecology, Taxonomy, Conservation, Photography, Butterfly Holidays, Photo Galleries, Book Reviews and more.........
Text and photographs protected by Copyright © Adrian Hoskins 2007, and must not be published in part or in whole elsewhere without prior written permission from the author.
Butterflies of Britain & Europe
 
Large White
Pieris brassicae LINNAEUS, 1758
Family - PIERIDAE
subfamily - PIERINAE
Tribe - PIERINI
 
 introduction | habitats | lifecycle | adult behaviour
 
Large White Pieris brassicae, 2nd brood male, Noar Hill, Hampshire, England
 
Introduction
 
The Large White, often inaccurately referred to as the Cabbage White, is distributed across the whole of Europe including the Mediterranean islands and the sub-arctic areas of Scandinavia. It also occurs in Morocco, Algeria, Tunisia, Libya, and across temperate Asia to the Himalaya mountains. It does not occur naturally beyond these regions, but was accidentally introduced to Chile. The similar species, Pieris cheiranthi is endemic to the Canary Isles.
 
Female Large Whites have a pair of prominent black spots in the median area of the forewings, but these are absent in the male. The spots are visible on the underside forewings of both sexes.
 
Both sexes can be confused with the Small White Pieris rapae, but in that species the dark markings are more feint - greyish rather than black - and the wingspan averages only 48mm, as compared to the 63mm ( male ) and 70mm ( female ) of brassicae.
 
When seen in flight the Large White can be confused by less experience lepidopterists with the female Brimstone Gonepteryx rhamni, but the latter always has a slightly greenish tint, whereas brassicae is a very bright and pure white.
 
The species is widely reared in science laboratories and used as a subject for study by geneticists, biochemists and physiologists.
 
Habitats
 
As with most other "whites", the Large White is strongly migratory and can appear in any habitat including woodland, open grassland, mountainsides, farmland, heathland and city centres.
 
In Britain it is commonly seen in coastal areas during migratory influxes, and often occurs in high numbers on flowery chalk grassland habitats in mid summer.
 
The butterfly breeds primarily in gardens, allotments and on arable farmland where it can become a pest on cultivated Brassica. It also breeds on garden nasturtiums.
 
Large White Pieris brassicae, 2nd brood male, Noar Hill, Hampshire, England
 
Lifecycle
 
There are usually 2 broods of this species in Britain, emerging in May and August, but the emergence times are subject to modification by climatic conditions. The resident population is supplemented by migrants from Europe, which often arrive in large numbers during the spring and summer. Thus it is possible to see adults of this species at any time from March to October.
 
Numbers fluctuate greatly from year to year, largely in response to climatic conditions and cycles of parasitism, but partly influenced by the number of migrants arriving in the spring from mainland Europe.
 
The deep yellow skittle-shaped eggs are laid in batches of up to 100, on the underside of cabbage, sprout or nasturtium leaves. The butterflies have been shown to be able to detect the presence of existing egg batches laid by other females, and will not normally lay additional batches on the same plant. The eggs hatch after about 10 days.
 
The larvae feed communally, entirely stripping the plants of leaves before moving on to adjacent plants. They are conspicuously marked in black and yellow aposematic colours, and sequester mustard oils from the foodplants, which render them distasteful to avian predators. The mustard oils contain sulphur compounds, which bestow the larvae and their droppings with an unpleasant odour.
 
A high percentage of larvae are attacked by parasitoid wasps Apanteles glomeratus, which devour the internal tissues, and emerge from the larvae when they are fully grown, at which time the dead larvae can be found covered with clusters of tiny yellow cocoons.
 
The chrysalis is formed in a vertical or horizontal position, attached by the cremaster and a silken girdle to walls, fences or woody stems. When first formed it is a dirty greyish green colour, covered with small black and yellow spots. The chrysalis of the summer generation hibernates, and during the winter it's colour fades to a pale dirty buff colour.
 
Many pupae, when freshly formed and soft, are attacked by another parasitoid wasp, the tiny metallic green Pteromalus puparum, which completes it's entire lifecycle within the chrysalis, emerging as adults from tiny exit holes.
 
Large White Pieris brassicae, 2nd brood male, Noar Hill, Hampshire, England
 
Adult behaviour
 
The adult butterflies are highly mobile, covering vast distances and exploring all available habitats in search of their larval foodplants and nectar sources. In spring they will nectar at dandelion, bugle and wood spurge. In summer they strongly favour thistles, knapweeds and buddleia, although they will also visit hemp agrimony, marjoram, field scabious, devil's bit scabious and various other flowers.
 
They have a powerful undulating flight which is undeterred by obstacles such as trees, bushes and buildings, over which the butterflies commonly fly.
 
I have not observed any form of courtship ritual, but have often found copulated pairs at rest on low foliage or on robust flowers.
 
In overcast or hazy conditions the butterflies often bask on low foliage or amongst grasses, holding their wings half open so as to reflect solar energy onto the dark thorax.
 
The butterflies roost overnight in bushes or high in trees.
 
                                                       
Almost every British and European species of butterfly is declining rapidly in numbers, due in most cases to loss or degradation of habitats.
 
You can help to reverse the decline by supporting conservation organisations which purchase and manage habitats as nature reserves, and which lobby government at local, national and international levels, often very successfully, to bring about changes in farming, forestry and urban development policies.
 
Please contact the conservation organisations for advice on how you can help protect British and European butterflies and their habitats. You may be able to offer practical help e.g. by monitoring butterfly populations or helping to manage nature reserves. Donations to these organisations enable them to employ ecologists and biologists. Even if you are unable to provide such help, merely having your name on the membership list can be a powerful tool for conservation organisations wishing to demonstrate the levels of support they have for their policies.

 

 
Text and photographs protected by Copyright © Adrian Hoskins 2007-2008, and must not be reproduced or published in part or in whole elsewhere in any form without written permission from Adrian Hoskins. Breach of copyright will be pursued by litigation.
 
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