The Wood White is one of our daintiest butterflies with one of the slowest and delicate flights of all the British butterflies. When at rest, the rounded tips of the forewings provide one of the main distinguishing features between this butterfly and other "whites". Adults always rest with their wings closed. In flight, the male can be distinguished from the female by a black spot at the tip of the forewings that is greatly reduced in the female. This butterfly lives discrete colonies and was only recently separated from the visibly-identical Cryptic Wood White. This local species can be found in central and southern England and also in Ireland on the limestone pavements of Clare and South-east Galway. This species is absent from Scotland, the Isle of Man and the Channel Islands.
Aside from the confusion that has historically surrounded the identification of L. sinapis, L. reali and L. juvernica, several other taxonomic names have been applied to L. sinapis.
Hübner (1823) uses f. lathyri to describe the spring generation. f. sinapis, the nominate form, is then used to describe the summer generation.
Verity (1916) uses f. transiens to describe the British population and mentions the distinguishing features: "The British race is quite similar in both generations to the nymo-typical one; it is a little smaller than the one from the South of Europe; a careful comparison also shows that the dark bands on the underside of the hindwings in the summer broods are more diffused than in Italian specimens, thus differing a little less from the spring brood than in the latter region; form transiens, mihi; "types" from the New Forest in July".
This species was first defined in Linnaeus (1758) as shown here (type locality: Sweden). Males of the summer brood have darker wing spots than those of the spring brood, whose spots are greyer in colour. Females of the summer brood are slightly smaller than those of the spring brood.
The English colonies emerge in early May and fly until the end of June. In Ireland, the emergence starts a little later in late May and the adults fly until the middle of July. Some sites, especially those in Surrey and Sussex, typically experience a 2nd brood and this can be more substantial than the 1st brood in good years.
The chart(s) above have been correlated with the phenology plot below, taken from the UK Butterfly Monitoring Scheme. The blue line gives average counts over the full data set from 1976 to date, and the red line gives the average for the last year.
As its name implies, this species is found in woodland rides and margins. However, colonies in the south west of its range can be found in more-open areas such as disused railway cuttings and meadows. Suitable habitat is characterised as being warm, sheltered and damp, where both larval foodplants and nectar sources are in abundance. Foodplants include various vetches and trefoils. Nectar sources include a variety of flowers, favourites being Bramble, Bugle, Ragged Robin and Birds-foot Trefoil. In hot weather, males can also be found taking mineral salts from puddles.
The primary larval foodplants are Bird's-foot Trefoil (Lotus corniculatus), Bitter Vetch (Lathyrus linifolius), Greater Bird's-foot Trefoil (Lotus pedunculatus), Meadow Vetchling (Lathyrus pratensis) and Tufted Vetch (Vicia cracca).
Adults feed primarily on Bird's-foot Trefoil (Lotus corniculatus). Bramble (Rubus fruticosus), Bugle (Ajuga reptans), Buttercups (Ranunculus spp.), Greater Stitchwort (Stellaria holostea), Ragged Robin (Lychnis flos-cuculi), Red Clover (Trifolium pratense) and Vetches (Vicia spp.) are also used.
Males are the more active of the two sexes and can be found patrolling for females, rarely stopping to rest or feed, especially in sunny weather. On dull days, the butterfly will rest on the underside of a leaf with its wings closed and, when disturbed, the butterfly will fly into thick undergrowth.
The courtship of this butterfly is an amazing spectacle. Male and female face each other with wings closed and intermittently flash open their wings. At the same time, the male waves his proboscis and white-tipped antennae either side of the female's head. If the female is receptive to these signals, the female bends her abdomen toward the male and the pair mate, staying coupled for around 30 minutes.
Description to be completed.
Click here to see a full list of aberrations for this species.
The yellowish-white and skittle-shaped eggs are laid singly on the underside of a leaf, on sheltered plants. They hatch after about 2 weeks.
The superbly-camouflaged larva feeds by first eating the tips of the finest shoots, before working its way down the plant. There are 4 moults in total.
The pupa is primarily green, although the wing edges and veins are a beautiful pink. It is attached to the stem by a silken girdle and the cremaster. Those pupae that do not give rise to a new generation in the same year overwinter.
The Cryptic Wood White and Wood White can only be differentiated by a detailed examination of their genitalia.
Click here to see the distribution of this species overlaid with specific site information. Alternatively, select one of the sites listed below.
|Ballyvaughan, Betty Daw's Wood, Branscombe, Branscombe Cliffs, Bury Ditches, Chambers Farm Wood, Coldwell Copse, Common Hill, Coombe Heath, Dunscombe Cliffs, Dunsdon NNR, Foxholes, Haldon Butterfly Walk, Haldon Woods, Haugh Wood, Howe Park Wood, Kingcombe Stones, Lea and Pagets Wood, Little Linford Wood, Lough Bunny, Lyme Regis Undercliff, Marks Hall Estate, Monk Wood, Mount Fancy Reserve, Nupend Wood, Oaken Wood, Pentaloe Glen, Powerstock Common, Quoditch Moor Nature Reserve, Salcey Forest, Stonebarrow Hill, Woodside|
Despite relatively short-term increases, the long-term view is that this butterfly is in decline and is therefore a priority species for conservation efforts. This butterfly has suffered due to a change in woodland management and, in particular, the reduction in coppicing that allows new woodland clearings to develop that provides the conditions suitable for this species. Even improvements in habitat management will not guarantee that the species will reappear from areas where it has been lost, since it is not a very mobile species and may not, therefore, be able to recolonise naturally.
The table above shows the distribution and population trends of species regularly found in the British Isles. The distribution trend represents a comparison between data for the periods 1995-1999 and 2005-2009. The information provided is taken from the Butterfly Conservation report The State of the UK's Butterflies 2011. The UK BAP status is taken from the UK Biodiversity Action Plan (UK BAP) (2007 review).
The following links provide additional information on this butterfly.
The species description provided here references the following publications: