Fig. 11.Butterfly Plumules.a.Tufted Plumule (Satyrs);b.Bristle Plumule (Grizzled Skipper);c.Hair Plumule (Dingy Skipper);d.Jointed Plumule (Silver-studded Skipper);e.Bladder Plumule (Common Blue);f.Dotted Plumule (White-letter Hairstreak).(After Aurivillius.)
Fig. 11.Butterfly Plumules.a.Tufted Plumule (Satyrs);b.Bristle Plumule (Grizzled Skipper);c.Hair Plumule (Dingy Skipper);d.Jointed Plumule (Silver-studded Skipper);e.Bladder Plumule (Common Blue);f.Dotted Plumule (White-letter Hairstreak).(After Aurivillius.)
Fig. 11.Butterfly Plumules.a.Tufted Plumule (Satyrs);b.Bristle Plumule (Grizzled Skipper);c.Hair Plumule (Dingy Skipper);d.Jointed Plumule (Silver-studded Skipper);e.Bladder Plumule (Common Blue);f.Dotted Plumule (White-letter Hairstreak).(After Aurivillius.)
In the foregoing sketch of the life cycle of a butterfly, the object has been to condense as much necessary information as possible into a limited space. Many matters of importance to the student have not been touched on, but it was consideredthat, as these were more especially connected with a higher scientific phase of the subject than would here be found helpful, they might be omitted.
Fig. 12.Y-piece
Fig. 12.Y-piece
Fig. 12.
Y-piece
Naturally the first matter for consideration, when the formation of a collection of butterflies has been decided upon, is how to set about it. Well, there are two methods of effecting our purpose. The specimens may be purchased from a dealer in such things, or we may acquire an outfit comprising net, boxes, and pins, and go in search of the insects ourselves. Apart from its healthful and entertaining possibilities, the latter method has very much to recommend it. In the first place, those who are at all observant—and no true lover of Nature can be suspected of being otherwise—will become acquainted with the objects under natural conditions, and so be enabled to appreciate them more highly than could be the case if they were obtained in any other way. The chief purpose in making a collection of Natural History specimens should be study of some kind rather than mere accumulation.
Nets.
The net may be a simple cane ring one of home construction, or the more elaborate, but not necessarily more efficient, fabrication of steel-jointed ring with grenadine bag and telescopic handle. A good serviceable butterfly-net may be fitted up as follows. Procure a light flexible cane, about 3 feet or so in length. Next, a Y-shaped holder (Fig.12) for the two ends of the cane will have to be made, and either tin or brass may be used for the purpose. The latter is the better metal, and theparts should be brazed and not soldered together. (If difficulty is experienced in the manufacture of this article, it may be obtained from any dealer in entomological requisites for a few pence.) The bag may be made of leno, tarletan, or fine mosquito netting; the latter is the most serviceable, and should be used wherever it can be obtained. The size of the bag at the top, where it has a wide band to take the cane, should not exceed the circumference of the cane ring when fitted in the two arms of the Y-piece; the depth should be just a little less than the length of one's arm, and the bottom should be rounded off so that no corners are available for the butterflies to get into and damage their wings. An opening about 3 inches in length is left in the seam of the bag just under the Y-piece, so that the cane may be removed and rolled up when the net is put out of action. The ring band should be covered with some stouter material to prevent it from fraying, thin leather is sometimes used for this purpose; the slit in the seam also requires protecting on each side, and strengthening at the lower end by a crosspiece. An ordinary walking-stick, with the ferrule end thrust into the longer tube of the Y, will serve as a handle to the complete net.
Fig. 13.Kite or Balloon Net.
Fig. 13.Kite or Balloon Net.
Fig. 13.
Kite or Balloon Net.
The dealers adverted to above generally stock a variety of nets ready fitted for use. Among these is a very useful pattern known as the kite or balloon net (Fig.13). This is made in two sizes, and as the writer has used this kind of net for at leasttwenty years, he is able to speak well of its merits. It does not need a stick for ordinary work, and the long end of the socket should be about 9 inches in length.
The "ring" being made of four separate rods, in addition to the Y-piece, some care will have to be taken when a balloon net is unshipped. It will be found a good plan to leave the two short curved canes in the hem or band of the bag, remove the two straight arms from the Y-piece and the band, place these on top of the bag when folded, and then roll all up together. A canvas or linen pouch or pocket, opening at one end, may be made to contain the whole affair.
The umbrella-net, when in its case, looks very like the familiar "gamp." Its chief merit is that it is quickly put up for use, and its principal defect is that the stick, which crosses the mouth of the bag, frequently damages the quarry.
Another implement of the chase known as the "Ortner" net is used pretty extensively on the Continent. English entomologists who have used it speak of it most favourably. Its great advantage over other nets is found in the simple and rapid method of its adjustment for use.
In connection with nets it may be well to advise the wielder to remember that carrying a threaded needle is a useful practice. Tears and rents are apt to occur, and it is well to have the means of repair handy.
Killing.
Some collectors seem to be expert at killing butterflies by pressing the sides of the thorax together. The method is not, however, as satisfactory as one could wish, and so no more need be said about it. For the happy despatch of insects, the cyanide bottle is frequently used. All that has to be done is to clap the open bottle over the captive while still in the net, then draw the gauze or what-not over the mouth of the bottle until the bung can be inserted, and the whole affair withdrawn from the net.
Cyanide of potassium is a deadly poison, and no inexperiencedperson should attempt to charge a cyanide bottle himself. In fact, chemists are not permitted to supply the poison to unknown customers. Under certain conditions, however, a chemist might consent to make up a killing bottle, and the following instructions may help him in doing this. A fairly strong, clear glass bottle, holding about 4 to 6 ounces; the mouth must be pretty wide, and closed with a well-fitting bung that has been dipped in melted wax; if the bung is of fine grained cork, the wax will not be needed. At the bottom of the bottle place a thick layer of the cyanide, and over this pour plaster of Paris which has been mixed with water and converted into a cream-like paste: one-third of the depth of the bottle to be occupied by the poison and plaster, but only a thin layer of the latter should cover the former.
Dealers who supply cyanide bottles (uncharged) also have in stock a brass bottle for chloroform, which some people prefer as a killing agent because it does not change the colour of insects as cyanide is occasionally apt to do. In using this, the insect should be boxed, then a drop of the chloroform may be allowed to run from the bottle over the perforated lid or bottom of the box, and a finger put over the hole or holes for a short time.
The majority of butterflies, if transferred to pill boxes from the net, settle down quietly. In this way they may be taken to one's home and there placed, boxes and all, into the ammonia jar, a simple but very effective contrivance. To start one of these lethal chambers, procure a good sized pickle jar, one of the brown earthenware kind, holding about 2 gallons. At the bottom put in several layers of stout blotting-paper, and have ready a covering for the mouth of the jar. This covering may be of skin, waterproof-apron material, or even thick brown paper. Before turning the boxes into the jar, lift up the blotting-paper, drop in about half a teaspoonful of strong liquid ammonia (⋅880) and replace blotting-paper. Directly the boxes are in the jar,put on cover and tie it down securely. If brown paper is used, a piece of pasteboard should be put over it and a weight on top of that. Suffocation takes place directly the gas reaches the insect, but it often happens that one or more of the boxes exclude the gas longer than others. At the end of half an hour all may be removed, but the insects will not hurt in any way if left in all night.
The best kind of boxes for field work are those known as "glass bottomed," as in these the captives can be examined and, if not wanted, may be set free. It is always better to retain only those specimens that we know are really useful, rather than to incur the necessity of throwing away insects after we have deprived them of life.
Pinning.
If butterflies are pinned on the spot, a collecting box will be required, and the most useful and convenient is one of an oval shape. This should be made of zinc, and lined with cork that is held in place by zinc clips. The cork should be kept damp when in use, and the water used for damping should have a few drops of carbolic acid mixed with it so as to prevent the formation of mould. Insects may remain in such a box for several days without injury. This box will also be useful for relaxing specimens that have been badly set, or have been simply pinned during the busy season.
In the matter of pins, it is not altogether easy to make suggestions. There are, perhaps, only two makers in this country of entomological pins, and each of these supplies a large number of sizes. The selection of suitable pins will largely depend on the method of setting adopted. Black pins are, however, the best for butterflies, and are now used almost exclusively.
In pinning a specimen care should be taken that the pin passes in a direct line through the centre of the thorax. Insects that are properly pinned set better, and have a neat appearance when arranged in the collection. For regulating theheight of specimens on the pin, a handy graduated stage has been devised by Dr. Scarancke (see Fig.14). Each of the little rests are hollowed to receive the body of the insect, so suppose we wish a quarter of an inch of the pin to show below the body of a specimen, the pin is pushed through a perforation in the centre of the rest groove marked "3/16" until the point touches the wooden base, and we have the required length.
Beginners would, perhaps, find three sizes of pins quite sufficient for almost every purpose—say, Nos. 10, 8, and 5 of one maker; or Nos. 9, 17, and 5 of the other. In each case the first size pin would be suitable for small butterflies, the second size for all other butterflies except quite the largest, for which No. 5 would remain. English pins are sold by the ounce.
Fig. 14.Pinning Stage.
Fig. 14.Pinning Stage.
Fig. 14.
Pinning Stage.
Setting.
Setting, as it is called, that is, spreading out and fixing the wings so that all their parts are displayed, arranging the horns, etc., is perhaps the most tedious work that the collector will be called upon to perform. The various methods will be referred to, and he must then decide as to which he will adopt. Each style may possibly be found to have its difficulties at first; but time and patience will overcome these, therefore he must be prepared for a good deal of troublesome practice before he quite gets "the hang of the thing," and canset out his specimens without removing a greater or lesser number of the scales.
Fig. 15.Board for Flat-setting.
Fig. 15.Board for Flat-setting.
Fig. 15.
Board for Flat-setting.
First, as to the flat and high setting as practised by almost every lepidopterist abroad and by some in our own country. Boards of the pattern, shown in the illustration, will be required; also some tracing cloth, and a pair of entomological forceps, bead-headed pins, etc. In these boards, it will be noticed, the sides tilt outwards; this is to allow for drooping of the wings, which generally occurs after insects are removed from the "sets." In this case the wings would settle dead flat, which is considered to be the acme of perfection in this style of setting. Carlsbad or other foreign pins would be used for this kind of work. They are of a uniform length, about one inch and a half, but vary in thickness, and are usually sold by the 100 or 1000.
Fig.16.Fig.17.Longitudinal Section of Setting-board.Setting-board in use.
Fig.16.Fig.17.Longitudinal Section of Setting-board.Setting-board in use.
Fig.16.Fig.17.
Longitudinal Section of Setting-board.Setting-board in use.
Manipulation of the specimen on these boards is as follows. Having carefully pinned it, leaving the greater length of pin below the insect, guide the pin carefully through the narrow opening (aFig.15and the cork (Fig.16) below to a suitable depth, so that the body of the insect rests in the groove and the wings lie easily on the board. Then take two strips of tracing cloth, glazed side downwards, and pin them on at the end of each side of the setting-board (Fig.17). The strip should be just wide enough to cover all but the basal part of the wings. Now pass the strips over the wings, press one side lightly with the fingers of the left hand while the wings are moved into position with the setting needle (a fine needle with eye end fixed into the stick of a small penholder will do for this) from the uncovered base, a pin being inserted below the fore wing while the hind wing is brought into position, but when thishas been done and another pin inserted to keep it in place, as shown in the diagram, the first pin may be removed; repeat the same operation on the other side. Other pins will be required to keep the horns, etc., in place. In dealing with the next specimen the strips will have to be turned back while it is fixed into position, then proceed as before. An imaginary line following the inner margin of the fore wings and passing through the pin on the thorax is an excellent guide to uniformity in setting. The groove will prevent the pin leaning to either side, but care should be taken that it does not incline either forwards or backwards. The strip of tracing cloth may be used more than once, but the roughness of the pin holes should be removed by drawing the strip across the back of a knife.
Fig. 18."Saddle" Setting-board.
Fig. 18."Saddle" Setting-board.
Fig. 18.
"Saddle" Setting-board.
The setting-boards most frequently used in this country have sloping sides, and are known as saddles (Fig.18). Where tracing cloth is used, themodus operandiis exactly similar to that just described, but small pins will do for pinning down the strips, as the saddles are made of cork, or cork carpet, instead of wood.
Fig. 19.Setting-bristle.
Fig. 19.Setting-bristle.
Fig. 19.
Setting-bristle.
The following method of setting butterflies on the English kind of "board" or saddle is frequently adopted. Select a suitable saddle, that is one that has the groove wide enough to take the body, and rather wider than the wings when expanded. A setting bristlewill then be required. This is made, as shown in Fig.19,by fixing a fairly long and stout bristle, or a very fine needle, or a thin length of quill, in a cube of cork; the cork cube has a stoutish and sharp-pointed pin pushed through it as indicated. Having placed the first insect on the saddle with its body comfortably resting in the groove and the wings flush with the surface, the setting bristle is then brought into action. The point of the pin is rested on the saddle directly in the rear of the hind wing, and the top of the bristle touching the saddle in advance of the front wing. Tilt the pin slightly forward until the bristle presses lightly on the central area of the wings, then with the setting needle push the wings into the required position, and at the same time drive pin of bristle into the saddle. After the wings have been secured by means of braces (triangular pieces of thin card or stout paper, with a pin through the base of the triangle), proceed in thesame way with the other side. Finally, fix a brace to the tip and angle of each fore wing to keep them from turning up in drying, and a pin or two may be required for the horns if these are not in a good position. Instead of using braces, a strip of transparent paper may be pinned over the wings beyond the bristle, but in this case the bristle must be pressed across the wings at a point nearer their base than in the previous method (see lower figure in Fig.20). In lieu of a setting bristle a length of sewing cotton may be used. Tie a double knot at one end, and through this pass the point of a pin in such a way that the cotton lies flush on the saddle when in use. Insert the pin firmly in the saddle a little in advance of the fore wing, then draw the cotton downwards across the wings and hold it taut, with the fore finger of the left hand placed on it just in rear of the hind wing. Whilst so held the wings can be got into pose with the setting needle, and braces may then be applied as previously directed.
Fig. 20.Brace and Band Modes of setting.
Fig. 20.Brace and Band Modes of setting.
Fig. 20.
Brace and Band Modes of setting.
Fig.21shows a specimen set by a method that is in vogue in the north. Blocks of soft pine, grooved and bevelled as in the cork saddle, are easily made. Down the centre of the groove there is a saw cut for the point of the pin to enter, and nicks are cut along the bottom edge at each end. One end of a length of cotton is knotted and fixed in a nick, then a turn is taken over the wings on one side; these are placed in position and secured by other turns of the cotton. The other side is then treated in the same manner, and the end of the cotton fastened off in one of the nicks. This is a quick and, in skilled hands, a very neat method.
As specimens after being set will have to remain on the setting boards or saddles for at least a fortnight, it will be necessary to protect them not only from dust, but from possible attack by ants, cockroaches, mice, etc. This is best ensured by placing the sets into a receptacle called a setting or drying house. Dealers supply these, but the young collector may have a knowledge of carpentry and could make one for himself. Theheight and depth of such a construction would depend upon the number and the width of the boards or saddles that would be put therein. The width would be that of the length of the boards, which is usually 14 inches. About a quarter of an inch of cork is cut off each end of the saddles, and grooves are cut in the sides of the house for these to run in. The back and the door should have a square of fine perforated zinc inserted in them for ventilation. As an example of holding capacity it may be well to note that a house with a height of 12 inches, and a depth of 6 inches, inside measurement, would take eighteen 2-inch boards if the grooves were cut at 2 inches apart, or twenty-four boards of same width if 1-1/2 inch only were allowed between the grooves.
Fig. 21.Cotton Method of setting.
Fig. 21.Cotton Method of setting.
Fig. 21.
Cotton Method of setting.
In taking insects off the sets, the braces or strips should be removed from the wings, and the pins from the horns, with care, as a good deal of damage can be done in the performance of this operation, simple as it seems to be. A little twist of a brace and away goes a patch of scales, a side slip of a pin and off comes a horn.
Pending the arrival of that twelve or twenty drawer cabinet, the beginner will probably be content to arrange his specimens in boxes. A handy sized box is one measuring 14 inches by 10 when closed, and it should have a cell for naphthaline.
Before putting the specimens away into boxes or drawersthey should be labelled with the date of capture, the locality, the name of the captor, and any other detail of interest in connection with it. All these particulars may be written on small squares of paper and put on the pins under the specimens.
Cabinets or boxes containing insects should always stand where they are free from damp, otherwise mould may make its appearance on the specimens. Mouldy insects may be cleaned, but they never look nice afterwards; so it will be well to bear in mind that prevention is better than cure. Where drawers and boxes are not properly attended to in the matter of naphthaline, mites are apt to enter and cause injury to the specimens. If these pests should effect a lodgment, a little benzine poured on the bottom of box or drawer will quickly kill them. The benzine, if pure, will not make the least stain, and of course the drawer or box must be closed directly the benzine is put in. Do this only in the daytime.
Rearing butterflies from the egg is much practised, and is a very excellent way. One not only obtains specimens in fine condition, but gains knowledge of the early stages at the same time. The eggs of most of the Whites, the Orange-tip, the Brimstone, and some others are not difficult to obtain, but searching the food-plants for the eggs of many of the butterflies is tiresome work, and not altogether remunerative. Females may be watched when engaged in egg-laying, and having marked the spot, step in when she has left and rob the "nest." The best plan is to capture a few females and enclose them in roomy, wide-mouthed bottles, or a gauze cage, putting in with them a sprig or two of the food-plant placed in a holder containing water. The mouth of the bottle should be covered with gauze or leno, and a bit of moistened sugar put on the top outside. Either bottle or cage must be stood in the sunshine, but it must be remembered that the butterflies require plenty of air as well as sunshine, and that they can have too much of the latter.
The Swallow-tail butterfly is the only British member of the extensive and universally distributed sub-family Papilioninæ, which includes some of the largest as well as the most handsome kinds of butterfly. Our species has yellow wings ornamented with black, blue, and red, and is an exceedingly attractive insect. The black markings are chiefly a large patch at the base of the fore wings, this is powdered with yellow scales; a band, also powdered with yellow, runs along the outer or hind portion of all the wings. There are also three black spots on the front or costal margin, and the veins are black. The bands vary in width, and that on the hind wings is usually clouded more or less with blue. At the lower angle of the hind wings there is a somewhat round patch of red, and occasionally there are splashes of red on the yellow crescents beyond the band. The male and female are shown on Plate2.
The eggs are laid on leaflets of the milk parsley (Peucedanum palustre), which in the fenny home of the butterfly is perhaps the chief food-plant of the caterpillar. This is one of the few eggs of British butterflies that I have not seen. Buckler says that it is globular in shape, of good size, greenish yellow in colour when first laid, quickly turning to green, and afterwards becoming purplish.
The caterpillar when full grown, as figured on Plate1,is bright green with an orange-spotted black band on each ring of the body, and blackish tinged with bluish between the rings. The head is yellow striped with black. When it first leaves the egg-shell, which it eats, the caterpillar is black with a noticeable white patch about the middle of the body. After the third change of skin it assumes the green colour, and at the same time a remarkableV-shaped fleshy structure of a pinkish or orange colour is developed. This is theosmaterium, and is said to emit a strong smell, which has been compared to that of a decaying pine-apple. The organ, which is extended in the figure of the full-grown caterpillar, is not always in evidence, but when the caterpillar is annoyed the forked arrangement makes its appearance from a fold in the forepart of the ring nearest the head. Other food-plants besides milk parsley are angelica (Angelica sylvestris), fennel (Fœniculum vulgare), wild carrot (Daucus carota), etc. From eggs laid in May or June caterpillars hatch in from ten to twelve days, and these attain the chrysalis state in about six or seven weeks. If the season is a favourable one, that is fine and warm, some of the butterflies should appear in August, the others remaining in the chrysalids until May or June of the following year; a few may even pass a second winter in the chrysalis. Caterpillars from eggs laid by the August females may be found in September, nearly or quite full grown, and chrysalids from October onwards throughout the winter. They are most frequently seen on the stems of reeds, but they may also be found on stems or sprays of the food-plants, as well as on bits of stick, etc. It would, however, be practically useless to search for the late chrysalids as the reeds are usually cut down in October, when the fenmen keep a sharp look-out for them, and few are likely to escape detection in any place that would be accessible to the entomologist.
Larger ImagePl.2.Swallow-tail Butterfly.1male; 2female.
Pl.2.Swallow-tail Butterfly.1male; 2female.
Pl.2.
Swallow-tail Butterfly.
1male; 2female.
Pl.3.Black-veined White Butterfly.Eggs, natural size and enlarged; caterpillar and chrysalis.
Pl.3.Black-veined White Butterfly.Eggs, natural size and enlarged; caterpillar and chrysalis.
Pl.3.
Black-veined White Butterfly.
Eggs, natural size and enlarged; caterpillar and chrysalis.
On Plate1three forms of the chrysalis are shown. The figures are drawn from specimens collected in Wicken Fen in October, 1905. Occasionally a much darker, nearly black, form is found.
This butterfly was known to Petiver and other early eighteenth-century entomologists as the Royal William. There is every reason to believe that at one time it was far more widely distributed in England than it now is. Stephens, writing in 1827, states that it was formerly abundant at Westerham, and gives several other localities, some very near to London.
During the last twenty-five years or so, the butterfly has been seen on the wing, from time to time, in various parts of the Southern and Midland counties. Caterpillars have also been found at large in Kent. Possibly attempts may have been made to establish the species in certain parts of England, and the presence of odd specimens in strange places may thus be accounted for. Or such butterflies may have escaped from some one who had reared them.
On the Continent the butterfly is common in woods as well as in meadows, and even on mountains up to an elevation of 5000 feet. It occurs also, but less commonly, at much higher altitudes. It therefore seems strange that in England it should be confined to the low-lying fens of Norfolk and Cambridgeshire. Such is the case, however, and a journey to one or other of its localities will have to be made by those who wish to see this beautiful creature in its English home.
It may be added that the geographical range of the butterfly extends eastwards through Asia as far as Japan. A form, known as the Alaskan Swallow-tail, is found in Alaska.
The following ten species belong to the Pierinæ, another sub-family of Papilionidæ.
The Black-veined White (Plate4) may be at once recognized by its roundish white wings and their conspicuous veins, which latter are black in the male butterfly, and in the female brownish on the main ones (nervures) and black on the branches (nervules). As the scales on the wings are denser in the male than in the female, the former always appears to be the whiter insect. On the outer margin of the fore wings there are more or less triangular patches of dusky scales, and these in occasional specimens are so large that their edges almost or quite meet, and so form an irregular, dusky border to the fore wings. These patches are also present on the hind wings, but are not so well defined. Sometimes the patches are absent from all the wings. The fringes of the wings are so short that they appear to be wanting altogether. The early stages are figured on Plate3.
The egg is upright and ribbed from about the middle to the curiously ornamented top, which appears to be furnished with a sort of coronet. The colour is at first honey-yellow, then darker yellow, and just before the caterpillar hatches, greyish. The eggs are laid in a cluster on the upper side of a leaf of sloe, hawthorn, or plum, etc., in the month of July.
The caterpillar when full grown is tawny brown with paler hairs arising from white warts; the stripes along the sides and back are black. The under parts are greyish. The head, legs, and spiracles are blackish. Caterpillars hatch from the egg in August, and then live together in a common habitation which is formed of silk and whitish in colour. They come out in the morning and again in the evening to feed, but a few leaves are generally enclosed in their tenement. In October they seem to retire for the winter and reappear in the spring. During May they become full grown and then enter thechrysalis state. The butterflies are on the wing at the end of June and in July.
Larger ImagePl.4.Black-veined White Butterfly.1, 2male; 3, 4female.
Pl.4.Black-veined White Butterfly.1, 2male; 3, 4female.
Pl.4.
Black-veined White Butterfly.
1, 2male; 3, 4female.
Pl.5.Large White Butterfly.Eggs, natural size and enlarged; caterpillar and chrysalids.
Pl.5.Large White Butterfly.Eggs, natural size and enlarged; caterpillar and chrysalids.
Pl.5.
Large White Butterfly.
Eggs, natural size and enlarged; caterpillar and chrysalids.
The chrysalis is creamy white, sometimes tinged with greenish, and dotted with black.
This butterfly was mentioned as English by Merret in 1667, and by Ray in 1710. Albin in 1731, who wrote of it as the White Butterfly with black veins, figures the caterpillar and the chrysalis, and states that caterpillars found by him in April turned to chrysalids early in May and to butterflies in June. Moses Harris in 1775 gave a more extended account of the butterfly's life-history, and what he then wrote seems to tally almost exactly with what is known of its habits to-day. This species has seemingly always been somewhat uncertain in its appearance in England. Authors from Haworth (1803) to Stephens (1827) mention Chelsea, Coombe Wood in Surrey, and Muswell Hill in Middlesex, among other localities for the butterfly. It has also been recorded at one time or another, between 1844 and 1872, from many of the Midland and Southern counties. In 1867 it was found in large numbers, about mid-summer, in hay fields in Monmouthshire. The latest information concerning the appearance of the species in South Wales relates to the year 1893, when several caterpillars and four butterflies were noted on May 22 in the Newport district. At one time it was not uncommon in the New Forest, but no captures of the butterfly in Hampshire have been recorded during the last quarter of a century. At the present time it is probably most regularly obtained in a Kentish locality, presumably in the Isle of Thanet, which is only known to a few collectors. It may be mentioned that some thirty years ago caterpillars of the Black-veined White could be obtained from a Canterbury dealer at a few shillings per gross.
The species is widely distributed, and often abundant, on the Continent, and its range extends through Western and Northern Asia to Yesso, Northern Japan.
This butterfly is probably almost as familiar to those who dwell in towns as it must be to those who live in the country. It is perhaps unnecessary to describe it in any detail, and it may therefore suffice to say that it is white with rather broad black tips to the fore wings; there are some black scales along the front margin of these wings, and on the basal area of all the wings. The male has a black spot on the front margin of the hind wings, and the female has, in addition, two roundish black spots on the fore wings, with a black dash from the lower one along the inner margin.
As there is a rather important difference between the specimens of the spring (vernal) and the summer (æstival) broods, figures of a male and a female of each brood, and showing the upper and under sides, are given. Those on Plate6represent the spring form, which was at one time considered to be a distinct species, and namedcharicleaby Stephens. Plate9shows the summer form. The chief point of difference is to be noted in the tips of the fore wings, which in the spring butterflies are usually, but not invariably, greyish; in the summer butterflies the tips are black, as a rule, but not in every case.
Occasionally the black on tip of the fore wing in the female is increased in width, and from it streaks project inwards towards the upper discal spot. In some examples of the male there is a more or less distinct blackish spot on the disc of the fore wings. Very rarely the ground colour is creamy or sulphur tinted.
The greenish tinge about the veins, sometimes seen in these butterflies, is due to some accidental cause, probably injury to the veins.
Larger ImagePl.6.Large White Butterfly (Spring Brood)1, 2male; 3, 4female.
Pl.6.Large White Butterfly (Spring Brood)1, 2male; 3, 4female.
Pl.6.
Large White Butterfly (Spring Brood)
1, 2male; 3, 4female.
Pl.7.Small White ButterflyResting.
Pl.7.Small White ButterflyResting.
Pl.7.
Small White Butterfly
Resting.
The egg is yellowish in colour, somewhat skittle-shaped, and very prettily ribbed and reticulated. On Plate5there are two figures of the egg from enlarged drawings by Herr Max Gillmer, to whom I am greatly indebted for the loan of them. In the figure on the right, the dark spot at the shoulder of the egg represents the head of the young caterpillar, and in that on the left is seen the caterpillar about to come out of the egg. The head is already out, and the jaws have left their mark on the egg-shell. Most caterpillars of the Whites, as well as those of other butterflies, devour their egg-shells.
The eggs are laid in batches of from six to over one hundred in each batch. They are placed on end, and on either side of a leaf, chiefly cabbage. Herr Gillmer writes that he watched a female depositing her eggs on a leaf of white cabbage in the hot sunshine, and found that she laid twenty-seven in about nine minutes. A previous observer had timed a female, and noted that she produced eggs at the rate of about four in the minute. Caterpillars hatch from the egg in about seven days in the summer. The caterpillar (Plate5) when full grown is green tinged with blue or grey above, and greenish beneath. There are numerous short whitish hairs arising from little warts on the back and sides; the lines are yellow. The caterpillars feed in July, and sometimes again in September and October, on all plants of the cabbage tribe, and also on tropæolum and mignonette. A number of these caterpillars may often be seen crowded together on a cabbage leaf, and they sometimes abound to such an extent that much loss is sustained by growers of this most useful vegetable. A peculiarity of these caterpillars is that even when not numerous, their presence is indicated by an evil smell that proceeds from them. The unpleasantness of the odour is greatly intensified if the caterpillars are trodden upon.
The chrysalis (Plate5) is of a grey colour, more or less spotted with black and streaked with yellow. It is often to be seen fixed horizontally under the copings of walls, the top bar of a fence, or a window-sill; but it sometimes affectsthe upright position when fastened in the angle formed by two pales. A position that affords some measure of protection from weather is generally selected.
Although this butterfly is almost annually to be seen, in greater or lesser numbers, throughout the country, it is occasionally scarce, either generally or in some parts of the British Islands. For example, during the past year (1905) it was abnormally plentiful in Ireland, but at the same time comparatively rare in England. It is a migratory species, and no doubt its abundance in any year in these islands is dependent on the arrival of a large number of immigrants. Possibly in some years none of the migrant butterflies reach our shores, and that it is largely to this failure the rarity of the species in such years is to be attributed. Caterpillars resulting from alien butterflies may absolutely swarm in the autumn of one year, but the eccentricities of an English winter may be too much for the vitality of such of them as escape their enemies,Apanteles glomeratus, and other so-called "ichneumons," and reach the chrysalis state. So, with immigration on the one hand and destructive agencies on the other, it may be understood how it comes about that the Large White is sometimes abundant and sometimes scarce.
This species seems to range over the whole of the British Islands, with the exception, perhaps, of the Shetlands. Abroad, it has been found in all parts of the Palæarctic Region, except the extreme north, and Eastern Asia.
The Small White butterfly (Plate11) is, perhaps, more often in evidence then its larger kinsman just referred to. It also is a migrant, and although it never seems to be absent from these islands, in its proper season, its great increase in numbers in some years is almost certainly due to the arrival of immigrants.
The spring form of this butterfly, namedmetraby Stephens, who, together with others, considered it a good species, has the tips of the fore wings only slightly clouded with black; and the black spots near the centre of the wings are always more or less faint in the male. Sometimes the central spot and also the blackish clouding of the tip are entirely absent. The summer brood, on the other hand, has fairly blackish tips and distinct black spots—one in the male and three in the female, the lower one lying on the inner margin. Occasionally examples of this flight bear a strong resemblance to the Green-veined White, the next species. The wings are sometimes, chiefly in Ireland, of a creamy colour, more especially in the female, or, more rarely, of a yellowish tint. In North America, where this species was accidentally or intentionally introduced some years ago, bright yellow forms are not uncommon in some localities, and the variety is there known asnovangliæ.
In certain favourable years a partial third brood has occurred, but such specimens are often small in size.
The egg (Plate8) is at first pale greenish, but later on it turns yellowish, and this tint it retains until just before the caterpillar hatches out.
The caterpillar when full-grown has a brownish head and a green body; the latter is sprinkled with black and clothed with short blackish hairs emitted from pale warts. There is a yellowish line on the back, and a line formed of yellow spots on the side. It feeds on most plants of the cabbage tribe, and in flower gardens on mignonette and nasturtiums. It is often attacked by parasites, and especially by theApanteles, referred to as destructive to caterpillars of the Large White.
The chrysalis may be of various tints, ranging from pale brown, through grey to greenish; the markings are black, but these are sometimes only faint. It is to be found insimilar situations to those chosen by the caterpillar of the last species, but often under the lower rail of a fence or board of a wooden building. Where caterpillars have been feeding in a garden, they often enter greenhouses, among other places, to pupate; and where these structures are heated during the winter, the butterflies sometimes emerge quite early in the year. Distributed throughout the British Islands, except the Hebrides and Shetlands. It is common over the whole of Europe, and extends through Asia to China and Japan. In America, where it was introduced into the United States some forty-five years ago, it has now spread northwards into Canada, and also southwards.
This butterfly is not often seen away from its favourite haunts in the country; these are woods, especially the sunny sides, leafy lanes, and even marsh land. As in the case of the two Whites previously noticed, there are always two broods in the year. The first flight of the butterflies is in May and June, occasionally as early as April in a forward season. These specimens have the veins tinged with grey and rather distinct, but are not so strongly marked with black as those belonging to the second flight, which occurs in late July and throughout August. This seasonal variation, as it is called, is also most clearly exhibited on the under side. In the May and June butterfly (Plate13,left side) the veins below are greenish-grey, and those of the hind wings are broadly bordered also with this colour. In the bulk of the July and August specimens (Plate13,right side) only the nervures are shaded with greenish-grey, and the nervules are only faintly, or not at all, marked with this colour.
Now and then a specimen of the first brood may assume the characters properly belonging to the specimens of the second brood; and, on the other hand, a butterfly of the second broodmay closely resemble one of the first brood. As a rule, however, the seasonal differences referred to are fairly constant. By rearing this species from the egg it has been ascertained that part (sometimes the smaller) of a brood from eggs laid in June attains the butterfly stage the same year, and the other part remains in the chrysalis until the following spring, the butterflies in each set being of the form proper to the time of emergence.