UK Butterflies

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Black-veined White

Aporia crataegi

a-POOR-ee-uh kra-TEE-jee

Wingspan
69 - 76 mm

Checklist Number
58.005

Black-veined White

Aporia crataegi

a-POOR-ee-uh kra-TEE-jee

Wingspan
69 - 76 mm

Checklist Number
58.005


First listed as a British species in 1667, this large butterfly became extinct in the British Isles around 1925 with its last remaining stronghold in the south-east of England. This species was always considered a rarity in the British Isles by early entomologists, although it is often very common on the continent.

This species forms discrete colonies that fluctuate greatly in numbers, although the cause of the ultimate demise of this species in the British Isles is a mystery since its foodplants can be found in abundance in all of its former sites. Disease (fostered by poor autumn weather), relatively-mild winters and increased predation by birds have all been suggested as potential causes of this demise. There was a successful reintroduction in Fife, Scotland, although this was only able to survive with appropriate protection of the larvae from birds. This species is extinct in the British Isles. This species was concentrated primarily in the southern half of England and south Wales. The strongholds were in Kent (which held 40 colonies), Hampshire, Gloucestershire and Sussex.

This species was first defined in Linnaeus (1758) as shown here (type locality: Sweden).

Description to be completed.

This species is extinct in Britain and/or Ireland.

1.1 Extinct

Early records of this species showed that it occurred in orchards, lanes, gardens, meadows and wherever its foodplants occurred in abundance.

No conservation action is relevant for this species.

In the British Isles, this species emerged in late June, peaked in July and survived into August. This butterfly has one generation each year.

An interesting characteristic of this species is that the female, by rubbing her wings together, loses many of her scales, resulting in an almost-transparent look when compared with the white wings of the male. The purpose of this behaviour remains a mystery.

Description to be completed.

Eggs are laid in batches of between 100 and 200, generally on the underside of a leaf of the foodplant. Eggs are bright yellow when first laid, darkening after a few days. The eggs hatch in 2 to 3 weeks, depending on temperature.

"In this country the eggs are laid during July on hawthorn, blackthorn and different kinds of cultivated plum, in batches varying from 100 to 200 eggs. On July 15th, 1903, three captured females were placed on young plum trees covered over with gauze. The following day there was but little sunshine, consequently no eggs were laid, but the next day (17th) being warm and sunny, two of the females deposited three batches of eggs, one batch on the upper side and two on the underside of the leaves. Before putting the butterflies on the trees they were fed with sugar and water, which they imbibed freely for half an hour. They were also fed daily while on the trees. On the 23rd another batch of eggs was deposited on the upper surface of a leaf, and a smaller batch on the underside of another leaf on the following day. Owing to the continuance of cold, dull, wet weather, with only a very little sunshine during early mornings, they remained quiet day after day. Two died in the first week of August, the last one died on August 9th without depositing any eggs, this one being a specimen in most perfect condition when captured on July 13th, obviously the day of emergence; she therefore lived for twenty-seven days, which is probably about the duration of life of crataegi in the perfect state. As all the larvae died during hibernation (probably due to the exceptionally wet autumn and winter of 1903) the same locality was again visited in July, 1904, when this species was found to be much scarcer than in the previous year. Five more females were captured on the 5th and 6th of that month. These were placed on a small plum tree on the morning of the 8th, and by midday two batches of eggs were deposited, and another batch on the 9th. The eggs hatched August 1st. Respecting the five batches of eggs laid July, 1903. The small batch, containing about 100 eggs deposited July 17th, remained without changing colour until August 8th, when they became duller on the crown, and on the following day they assumed an olive or greenish-ochreous hue, and dark on the crown; during the night they commenced hatching and all were hatched by early morning of the 10th. All that day they remained clustered together upon the empty egg-shells, but in the evening they gradually moved off. These likewise were twenty-three days in the egg state. As the weather remained so cold and wet, and fearing the other batches out of doors would not hatch, another lot were moved indoors on August 20th. The next day they showed signs of changing colour, and these also began hatching on the night of the 23rd, and by next evening all had hatched. Another batch left on the tree out-of-doors changed colour on the 24th and hatched on the 26th. The two remaining batches hatched during the first week of September. In a state of nature the eggs probably would be deposited on the under surface of the leaves, otherwise heavy rains would be likely to dislodge them, as they were quite easily removed with a finely pointed wet sable hair brush. The egg measures .94 mm. high and .51 mm. across the middle, its greatest diameter. In shape it resembles a rather elongated acorn; the micropyle is flat and smooth; there are usually fifteen, but sometimes sixteen, longitudinal keels, seven running from near the base to the summit, where each terminates in a glassy globe enveloping an opaque white knob; the remaining keels are simple at the ends, disappearing into the surface by the base of the globes; the spaces between the keels are angular and very faintly ribbed transversely. The colour when first laid is a bright, rich primrose-yellow, and remains unchanged until a day or two before hatching, as above described. They are deposited in rows closely packed, and stand erect." - Frohawk (1924)

The larva eats the majority of its eggshell on hatching before joining a communal larval web. Groups of larvae leave the web to feed side by side but remain within the web through the winter while still very small, in the 3rd instar. After emerging in the spring, the larvae continue this pattern of communal living, continuing to forage in groups. Larvae are particularly sensitive and will drop from the foodplant if disturbed.

As the larvae grow, they tend to form smaller groups that form sub-communities, each group creating their own web on which to rest. Ultimately, the gregarious behaviour is abandoned, and the fully-grown larvae disperse to feed individually prior to pupation.

The primary larval foodplants are Blackthorn (Prunus spinosa) and hawthorns (Crataegus spp.).

1st Instar

"Directly after emerging from the egg the larva measures 1.4 mm. long; the body is cylindrical, of uniform thickness, and wrinkled transversely, on the upper half the segmental divisions are clearly defined; there are three longitudinal rows of long tine white hairs on each side above the spiracles, each having a large bulbous base, and one immediately below the spiracle having a flatter base; the anterior dorsal ones on each segment curve forwards; the posterior one is shorter and straight, and the sub-spiracular one curves downwards; all have slightly knobbed and cleft tips. On the ventral surface, including the claspers and legs, are simple white hairs; the spiracles are brown and shining. The entire surface is densely sprinkled with minute dusky points, giving it a rough texture. The body (including the claspers) is pale ochreous-yellow, the legs dusky, and the head shining black, with a granular surface, pale olive-brown eye spots, and beset with about twenty-five whitish hairs, and a pair of very small black bristles in the centre. After leaving the egg-shells, which are considerably eaten, they spin a web over the surface of the leaf, living gregariously, all feeding upon the same part of the leaf. For the first twelve days they live exposed upon and under a slight covering of web; they then spin a denser web, and all retire within it." - Frohawk (1924)

2nd Instar

"The first moult occurred on or about August 23rd. On August 24th a few emerged from the web, and fed on the upper cuticle of the leaf, over which a thin layer of silk is spun in connection with the silken nest, into which they retreat and rest after feeding; only a few emerge at a time to feed. Shortly after the first moult it measures 3.2 mm. long. The head is large, black and shining. On the first segment is a black, chitinous band, and a black chitinous disc covering the dorsal surface of the last segment, resembling the head. The ground colour is an olive-yellow; the surface is sprinkled with minute black points and numerous long and short fine silky white hairs; some are very long and curved. The body is striped longitudinally with brownish on the dorsal surface; one stripe being medio-dorsal, the others sub-dorsal. The ground colour of the spiracular region is greyish, with a very fine longitudinal brown spiracular line; the spiracles are black. If disturbed they crawl rapidly, and retreat backwards like a micro-larva. When fifteen days old the larva measures 4.2 mm. long." - Frohawk (1924)

3rd Instar

"The larvae from the first batch of eggs, which hatched on August 9th, moulted the second time on September 2nd; others moulted during September. It is in this stage after the second moult that they hibernate. They feed in relays, numbering about one or two dozen individuals at a time; they march out of the nest together, and feed in a row side by side, feeding on the cuticle of the leaf, and retire in a body within the nest, formed of a dense silken web spun between the leaves. Many continued feeding until the third week in October, when all entered into hibernation. They hibernate in batches in separate compartments, varying in size and often woven side by side in the interior of the nest, which is a tough, dense, silken mass of a greyish colour, spun over the remaining parts of the leaves upon which they fed, and around the branches, generally between a small fork. On February 16th, 1904, one of the hibernacula was examined, and upon cutting open one of the compartments a little party of larva was found huddled together, the long soft hair of their bodies intermingling gives them the appearance of being enveloped in down; this, coupled with the density of the wall of the compartment and the massive outer covering of web, affords them great protection against cold and damp, the whole combined forming a very secure and snug abode. On March 24th, 1905, three larvae crawled out of their hibernacula, and rested on the outside of the web, followed the next day by others. On the 26th, a bright, sunny day, several emerged from different nests, and fed on the expanding buds, retreating into the webs after feeding. A few were put upon a sprig of plum bearing tender young leaves, and by the following day had fed a little. The next morning they were feeding on the base of the leaf upon which they rested in company, much as before hibernating. Directly after hibernation, and after second moult, they are very small, only measuring 4.2 mm. long, and similar in all respects to the previous stage, excepting the hairs are longer, forming a somewhat dense covering. Just before third moult it measures 6.35 mm. long." - Frohawk (1924)

4th Instar

"First one moulted third time April 9th, 1905; others continued moulting during the next few days. After third moult and a few days before fourth it is 15.9 mm. long. The body is nearly cylindrical and transversely wrinkled, the dorsal surface black, with a sub-dorsal longitudinal band, composed of orange blotches and speckles which cuts up the black into three stripes, the sides and ventral surface are olive-drab, minutely speckled with pale ochreous; on the dorsal surface are numerous slender bright orange hairs, and longer silky pure white ones scattered over the body, as well as a large number of shorter ones, all the hairs have shining black bulbous bases, each encircled with an ochreous ring; the head and legs are black, the former beset with hairs. They rest together in compact parties, dispersing to feed each time, and strip the twigs, leaving only the mid-ribs of the leaves, beginning first on the leaves at the ends of the branches and feeding downwards, returning to the tips to rest, and spinning webs each journey, backwards and forwards, forming a carpet of silk over the branches along which they travel." - Frohawk (1924)

5th Instar

"First one moulted fourth time April 21st, and all passed through this moult by the end of that month. After fourth and last moult, fully grown, about 280 days old, the larva measures from 32 mm. to 35 mm. long. During the last stage it greatly develops in size, being only 15.9 mm. long when first moulted, when the skin is rough and ample, which becomes stretched and shining when fully grown. In shape it is almost cylindrical, but slightly attenuated at each end. The dorsal surface is black with a sub-dorsal, longitudinal, ochreous-orange band, composed of numerous speckles, in the centre of each rises a fine hair, with a tiny black shining bulbous base; all the hairs excepting the white ones are either orange or amber, while the black surface is very finely granulated and sprinkled with shorter and very fine black hairs, and a few long wavy white ones, with an ochreous ring encircling the base of each; the whole surface below the sub-dorsal black band is very glossy, of a purplish-grey colour, thickly sprinkled with whitish-grey spots, each encircling a fine white hair, the entire surface of the body being hairy. The head is dull black and covered with black hairs; the anal segment, including the claspers, is also black; the other claspers are unicolourous with the body; the legs and spiracles are shining black. They rest stretched out along the twigs, often in small companies, lying side by side. The branches and leaves are always spun over with silk. Occasionally they hang suspended by a web. If touched several times they suddenly start crawling rapidly; they neither feign death nor roll in a ring. Before hibernation several had fed upon a laurel leaf which had come in contact with the plum branch upon which they were; they ate a large part of the upper cuticle of the leaf. Therefore a few larvae were supplied with laurel when in the last stage; although they fed on some of the young leaves, it caused them to vomit and one died in consequence. The first larva spun up for pupation early morning of May 14th, 1905, and pupated midday on the 16th, the transformation occupying about fifty-five hours. All the remaining larva pupated during the next week. Three of the larva when about 19 mm. long produced ichneumons (Apanteles) in a similar manner as they infest Pieris brassiae, emerging in clusters and spinning lemon-yellow cocoons over the body of the host, after which the latter gradually dies. Three more larger larva and another fully grown produced ichneumons on May 20th. The parasite apparently deposited its eggs in the larva during the previous autumn, as a few occasionally crept through the gauze covering the tree and rested on the outside for a time, when they were obviously discovered by the Apanteles." - Frohawk (1924)

The pupa is attached to a stem of the foodplant by a silk girdle and the cremaster and is often quite conspicuous and easy to find. This stage typically lasts around 3 weeks, depending on temperature.

"The pupa averages 25.4 mm. in length; the head is knobbed in front; at the base of the antenna is a short sharply-pointed spike; the meso-thorax is swollen, and keeled dorsally; the waist sunken; a slight abdominal dorsal keel, the base of wings angular; on the second, third and fourth abdominal segments is a lateral keel; the tongue case protrudes beyond the antenna and is detached, forming a spike; the anal segment terminates in a flattened, slightly curved horn, bearing the cremastral hooks, which are firmly attached to an ample pad of silk, and a girdle of silk passes round the body at the waist. The normal ground colour is a pale greenish-yellow of more or less intensity, some approaching a greenish-white; a black stripe passes over the crown and thoracic keel, and a broad black band runs along the ventral surface, including the antenna, tongue, legs and costal margins of the wings, only being broken up at the base of the legs by the ground colour and yellow eye spots. The 4 wings are broadly margined with black, and black vandyke markings on the inner edge of hind margin; a row of five black dots forms a median band, and usually there are one or two small discoidal spots, the spiracles are black and surrounded by conspicuous black markings; on each segment is a dorsal anterior black spot and three sub-dorsal smaller ones and two super-spiracular larger ones, these all form longitudinal rows. The thorax is also spotted with black. The frontal knob, dorsal and lateral keels, as well as two spots on the pro-thorax, a spot at base of the wings and anal extremity are all yellow. The whole surface is irrorated, and excepting the wings it is sprinkled with very fine extremely minute hairs. The ground colour is liable to vary as well as the size of the black markings. Those which pupated in coloured boxes, wherein some larva were placed when ready for pupation, were affected by certain colours: those in yellow produced decidedly yellow pupa; blue and green had the same result of producing green pupa; those on black and grey surfaces became greyer and those on white whiter. During June, 1905, forty-eight perfect imagines emerged." - Frohawk (1924)