1902 Encyclopedia > Butterflies and Moths

Butterflies and Moths




BUTTERFLIES AND MOTHS, the common English names applied respectively to the two groups of Insects which together form the order Lepidoptera (Gr. _____, a scale, and _____, a wing), an order characterized by the constant presence, in a greater or less degree, of scales on the wings. The two groups may, as a rule, be readily distinguished from each other, although, so far as our present knowledge goes, there is nothing in the structure or habits of either group which divides it entirely from the other. All butterflies are diurnal in their flight, while moths, with many exceptions, are crepuscular or nocturnal.

The bodies of butterflies and moths, like those of all other insects, consists of three distinct parts—the head, bearing the organs of sense ; the thorax, the organs of locomotion ; and the abdomen, the organs of generation. On the head are placed (1) the antennae, composed of numerous articulations, and supposed to be organs of hearing. They differ greatly in form among the Lepidoptera ; those of butterflies, however, agreeing generally in having their ends knobbed or clubbed, hence the term Rhopalocera (_____ , a club ; GREEK, a horn), often applied to this group. The antennae of moths assume a great variety of forms—prismatic, serrate, pectinate, moniliform, and filiform,—and are often beautifully feathered, especially in the males, whose antennae are usually ampler than those of the females ; but in no case are they knobbed, as in the great majority of butterflies. Owing to this variety in the form of their antennae, moths have been termed Heterocera (_____, various ; _____, a horn). In butterflies these organs are also straight, and stand out rigidly in front of the head, while in moths they are usually curved and can generally be folded back on body. (2) The eyes in the Lepidoptera consist of two masses of hexagonal facets, placed one on each side of the head, and forming what are known as compound eyes. These contain in some cases no fewer than 16,000 facest each, while in many species a pair of ocelli, or simple eyes, are found concealed among the scales and placed between the compound organs. The hairy appearance of the eyes in many of the Nymphalidae is owing to the presence of minute hairs planted at the angles of the numerous facets. Compound eyes are not found among the larvae of butterflies and moths, but they are in most cases provided with six ocelli on each side of the head. (3) the mouth, the parts, of which in insects are considered by comparative anatomists to be typically developed in the masticatory mouth of beetles (Coleoptera), assumes in butterflies and mouth of beetles (Coleoptera), assumes in butterflies and moths the suctorial form—the latter being merely a modification of the former ; thus the mandibles, labium, and labrum, which are fully developed when the nature of the food renders mastication necessary, are in a rudimentary condition in the Lepidoptera, whose chief food is the nectar of flowers, while the maxillae, on the other hand, are enormously developed ; being concave on their inner sides, these by approximating form a tube known as the proboscis or tongue. This when at rest is coiled up into a ball in front of the head, and is partly concealed by the palpi projecting on both sides. In the moths belonging to the family Bombycidae, the organs of the mouth are rudimentary, so that these insects after entering upon the imago state are incapable of feeding.

The thorax bears the organs of locomotion, consisting of three parts of legs and two pairs of wings. The former are covered with hairs and scales, and terminate in hooks modified to suit the habits of the various species. Butterflies use the legs almost entirely for resting, very rarely for walking, and in some groups, as the Nymphalidae, the front pair is rudimentary. The wings consist of a double layer of colourless membrane traversed by numerous nervures (Plate XXVII. fig 1), and covered with minute scales implanted in the wing membrane by a short stalk, and placed together like tiles on a roof. The scales very in form in different species and in different portions of the wings of the same species, while under a high power of the microscope they are seen to be minutely corrugated ; and it is to these corrugations acting upon the colourless rays of light, and producing the phenomena of interference," that many of the loveliest butterflies owe the brilliancy of their wings. The splendour of those organs in the majority of butterflies, and in some moths, is sometimes equally by both sexes, but more usually the females are less conspicuously coloured than the males. This different, amounting often to total dissimilarity, Darwin, in accordance with his descent theory, attributes in great part to the action of sexual selection. "Several males, "he says, "may be seen pursuing the same female." The latter he supposes selects the most gaily-coloured, and thus the plainer-coloured males have been gradually eliminated ; but there is no proof whatever that the female shows any such discrimination in selecting a mate, while many known facts seen to point in an opposite direction. Mr A.R. Wallace maintains, on the other hand, that the duller colours of the females have been acquired for protection purpose, the females requirement requiring such protection more than the males owing to their generally slower flight, and to the fact that after impregnation they take several days to deposit their eggs, during which the life of the male is of no further consequence to the perpetuation of the species. Whatever may be the true interpretation of this phenomenon, it is certain that many butterflies and moths of both sexes are so coloured as to be to a greater or less extent protected thereby. Many moths, which rest by day clinging to the trunks of trees, so exactly resemble in the colour of their upper wings the bark on which they rest as only to be distinguished on close examination ; while many small species which habitually rest on leaves are often mistaken for the dropping of birds. The surfaces of the wings of butterflies are in almost all cases the more gaily coloured, and when at rest, these are raised perpendicularly over the back, so as only to expose the under surfaces, which are often dull coloured, and in some cases have been shown to be directly imitative of surrounding objects. The best example of this is to be found in the Malayan butterfly, Kallima paralekta, and its Indian ally, Kallima inachis, both brilliant and conspicuous insects on the wing, but which no sooner alight than they become invisible. The under surfaces of their wings though varying greatly, yet form in every case a perfect representation of a leaf in some stage or other of decay, the butterfly at the same time disposing of the rest of its body so as to bear out the description. How this is effected is best told by Mr Wallace, who was the fist to observe it, in his valuable work on the Malay Archipelago.

"The habit of the species is always to rest on a twig and among dead or dried leaves, an din this position, with the wings closely pressed together, their outline is exactly that of a moderately sized leaf slightly curved or shrivelled. The tail of the hind wings forms a perfect stalk and touches the stick, while the insect is supported by the middle pair of legs, which are not notices among the twigs and fibres that surround it. The head and antennae are drawn back between the wings so as to be concealed, and there is little notch hollowed out at the very base of the wings, which allows the head to retracted sufficiently."

Moths, when at rest, have the hind wing folded close to the body, while the fore wings cover all, and it is the latter that usually show an assimilation in colour to surrounding nature. Many butterflies and moths, there seems good reason to believe, are coloured in imitation of other and often widely different species possessing some special means of protection, as sting or nauseous juices, the mimetic forms, it is supposed, sharing with their models in immunity from the attack of insectivorous animals. The phenomena of mimickry were fist observed by Bates among the Heliconidae a family of South American butterflies of South America butterflies, remarkable for their great numbers, the gaudiness of their colouring in both sexes and on both surfaces of their wings, and for their comparative slowness of flight. It was found that, owing to the nauseous nature of their juices, those brilliant butterflies were left unmolested by insect-eaters. It was also observed that several species of genus closely allied to our Cabbage Butterflies, totally different both in the colour and form of the wings from the Heliconidae, so closely resembled particular species of the latter as not to be distinguishable from them to wing. Exactly similar phenomena have been observed in the tropical regions of Asia and Africa, where the similarly protected Danaïdae and Acraeidae find imitators among the otherwise unprotected Papilios and Diademas. There are two families of day-flying moths, Sesiidae and Aegeriidae, with clear transparent wings, the scales being confined mainly to the margins and nervures, which in their wings and in the form and colour of their bodies might be readily mistaken for bees of wasps, a similarity, recognized in such specific names as bombiciformis, apiformis, vespiformis, &c., applied to different species of these moths. Other species of the same "clear wing" group have opaque wings closely resembling those of certain species of Coleoptera found in the same neighbourhood, and these have their wings when at rest closed over their bodies like the elytra of beetles.





Butterflies and moths undergo complete metamorphosis, that is, after emerging from the egg, and before attaining the full development of the imago, they pass through the larva and pupa stages—the latter being one of total inactivity in so far as the outward manifestations of life are concerned. The eggs vary greatly in shape, and are deposited in a great variety of situation—on the under sides of leaves, on the outside the cocoon, as in the Vapourer Moth (Orgyia antiqua), in the female of which is wingless, glued together in rings round the smaller branches of fruit tress, as in Clisiocampa neustria, or in the interior of hives, the larvae afterwards feeding on the wax, as an in the Honey-comb Moth (Galleria cerella). They thus show a remarkable instinct in depositing eggs in situations where the larvae may afterwards obtain their appropriate food, although them selves can have no knowledge of that food. The caterpillar emerges from the egg usually in a week or ten days. Unlike the perfect insect it is provided with a masticatory mouth. It has three pairs of legs on the anterior segments of its body, corresponding to the six legs of the future imago, besides which it is provided with a variable number of conical feet or prolegs placed posteriorly, and which are merely processes of the external covering of the caterpillar. Goossens, a Continental naturalist, has recently that the number of prolegs in some species differs at different ages, and gives a case in which a caterpillar with originally six prolegs acquired two additional pairs after the third moult. The body cavity is almost entirely occupied with the digestive system and with that concerned in the production of the silky material used in forming the cocoon. Silk is secreted as a viscous in tubes, which after many convolution widen into a large reservoir filled with the yellow liquid, narrowing again into a tube extending to the mouth, where it communicates the outside by means of a conical and jointed papilla known as the spinneret. Through this organ the viscous fluid is forced in two exceedingly delicate streams which coalesce, and on exposure to atmosphere harden to single continuous thread. The silky material is not completely formed till the caterpillar reaches maturity. Caterpillars are either smooth skinned or more less covered with hairs ; in the former case they are a favourite food of insectivorous animals, while in the latter they are almost universally rejected,—recent investigations on this subject to prove that the hairs on certain species of caterpillars have a power of stingging, somewhat analogous to that possessed by the hairs on the surface of a nettle.

No sooner does the caterpillar emerge from the egg than it begins to eat voraciously, and in a few days has grown so large that a change of skin becomes necessary. The old skin is cast off, with it the entire internal lining of the alimentary canal, and in the majority of butterflies and moths five such changes take place before the caterpillar has attained its full growth, while the Tiger Moth (Arctia caja) is said to cast its skin at least ten times. Those moultings do not usually affect the appearance of the caterpillar, except in enlarging it ; but in the case of Samia cecropia, a species, of Bombycidae, the larvae are said to pass from black to various of green and azureblue in the course of their moultings. The larvae of the family Psychidae—the larger members of which are found in America and Australia—have the curious habit of constructing cases which they carry about with them, and within which they afterwards undergo transformation. Each larva has but a single case, and when this get too narrow it splits longitudinally and is enlarged by interposing a new portion between. Moths and butterflies remain in the larval condition for periods varying from the three years, as in the Goat Moth (Cossus ligniperda), to a few weeks as in the Cabbage Butterfly (Pieris brassicae), which usually has two broods in the season, while many species whose larvae the egg in autumn, as the Blue Butterfly whose larvae leave the egg in autumn, as the Blue Buttefly (Polyommatus alexis), remain torpid throughout winter at this stage, and waken up to resume feeding in spring. During this period they increase enormously in weight ; thus the larva of the Privet Hawk Moth (Sphinx ligustri) which casts its sixth and last skin on the twenty-second day after emerging from the egg, attains its greatest size tend days after, having in the meantime increased to 11,312 times its original weight ; while the Goat Moth (Cossus ligniperda), which remains in the larval condition for three years, has grown in that period 72,000 times heavier. Having attained its full growth the instincts of the caterpillar undergo a change ; it ceases to eat and begins to weave a couch or cocoon by which it is more or less enclosed. It then throws off its skin and appears as a pupa or chrysalis incapable of eating or of locomotion, the only apparent sign of life which it manifests being a convulsive twitching when irritated. Examined more closely, however life is seen to be exerted in every great intensity in this stage of apparent quiescence. The immense digestive system of the caterpillar dwindles greatly, the rudiments of wings begin to show themselves, forming slight prominences on each side of the chrysalis shell, while the organs of the masticatory mouth are being transformed into those of the suctorial. In assuming the pupa condition caterpillars dispose of themselves in a great variety of ways. Many like the common Cabbage Butterfly, ascend walls and palings, to which they attach themselves by a silken belt, other, as silkworms, spin around them a solid cocoon of pure silk ; while the majority of Sphinx Moths form burrows in the ground, which they line with silk and after wards varnish to keep out the moisture,—one of these (Sphinx ligustri) remaining thus buried from August till June. Those larvae which feed on the wool of trees, as Cossus ligmperda, generally form tough cocoons of chips of wood and of silk within the tunnels which they have bored in the tree, and their pupae have the power of forcing themselves along those passages till they reach the bark where they remain until about to emerge from the egg, when they pierce it also. The cocoon of the Puss Moth (Cerura vinula), composed of the same materials as in the preceding instance, is usually placed in a crevice of the bark of a tree, where by exposure to the atmosphere it becomes hard as horn, the moth only making its escape after discharging a liquid it becomes encased in autumn it remains a pupa during the winter. By applying heat the process can be accelerated, and it can be equally retarded by refrigeration. When mature pupa case cracks towards the anterior end, and the butterfly or moth crawls forth with wins, though at first small and crumpled up, in a few hours attain their full size. The male insect goes in search of the female, and when the latter has deposited her eggs the mam object in the life of the imago is attained and both sexes die. Among the Bombycidae this occurs or three days, owing to the atrophied condition of the organs of the mouth. With butterflies courtship is generally a more prolonged affair, several males pursuing the same female, and breaking each others wings in the conflicts that thus frequently ensue. Butterflies appear in many cases to be gregarious, flying in great flocks. Bates states that at one place in South America he noticed eighty different species flying about in enormous numbers in the sunshine, and these, with few exceptions, were males, the females remaining within the forest shades. Darwin also describes a "butterfly shower," which he observed ten miles off the South American coast extending as far as the eye could reach ; "even by the aid of the telescope," he adds, "it was not possible to see a space free from butterflies. That they are occasionally migratory as well as gregarious is borne out by the observations of Sir J. Emerson Tennent, who witnessed in Ceylon a mighty host of butterflies of a white or pale yellow hue. "apparently miles in breadth and of such prodigious extensions as to occupy hours and even days uninterruptedly in their passage."

The food of Lepidopterous insects consists chiefly of the sweet liquids drawn the nectaries of flowers, which the reach by means of their long proboscis or tongue. Many of the Sphingidae said to do this without settling on the flowers, and one of the Humming Bird Hawk Moth of South America (Macroglossa titan), it its mode of flight and of posing itself before a flower while extracting the juice, bears such close resemblance to certain of the smaller humming birds inhabiting the same district, that Bates often shot it for one of the latter, and it was only after considerable experience that he learnt to distinguish the bird from the moth when on the wing. Although their food is thus usually the sweetest liquids drawn from loveliest vessels, still some of the most brilliant species seem to prefer more vulgar fare. Thus the showy Purple Emperor (Apatura iris) prefers above all things to suck the juices of putrid animal substances, and the surest way to secure specimens of this butterfly is by setting such baits near it haunts. Mr Wallace states that in Malacca he caught a large and brilliant butterfly which had settled on the dung of some carnivorous animal, where he had also observed it on the previous day, and he adds that it is a habit of many of the finest butterflies to suck up the liquid from muddy spots on the readside.





Butterflies and moths are widely distributed all over the globe, occurring, however, in greatest variety and abundance in tropical lands. They are found as far north as Spitzbergen, on the Alps to a height of 9000 feet, and to double that height on the Andes. In Britain there are only 66, and in the whole of Europe 390 species of butterflies ; while within one hour’s walk of Pará in Brazil, Bates found no fewer than 700 species. There are 1910 species of British moths, the majority of which are nocturnal and erepuscular ; while in tropical America day-flying moths seem to be most common, and may be seen in company with the sunshine-seeking butterflies. This paucity of nocturnal moths has been attributed to the great number of night-flying or crepuscular insectivorous bats and birds which haunt those regions. Many species both of moths and o butterflies have a very wide distribution the Painted Lady (Vanessa cardui), common British species, being found in every quarter of the globe ; and our finest butterfly, the Swallow Tail (Papilio machaon), occurring throughout Europe, Asia as far as the Himalayas, and South Africa. Other species are extremely local, as the Scotch Argus (Lycaena artaxerxes), confined to a few Scottish hillsides. Keferstein estimates the total number of Lepidoptera at 66,000 species—6000 butterflies and 60,000 moths. That such estimates, how ever, are not to be relied on is sufficiently proved by the fact that Bats gives the number of species as above 200,000. The geographical distribution of certain groups of Lepidoptera has been well wrought out by Mr Wallace and other naturalist who have studied them in their native homes ; but the division of this great order into geographical zones has still to be satisfactorily accomplished. Koch has recently proposed to place the in five such groups—(1) the European or Western fauna, including Northern Asia, the North of Africa (a region exceedingly poor in Lepidoptera, owing probably to the want of great forests, and to the marshy nature of vast tracts of land), and the northern parts of North America ; (2) the Africa fauna, allied to the preceding ; (3) the South Asiatic or Indian ; (4) the Australian and Polynesian, allied to the India ; and (5) the America fauna, distinguished by its exceeding richness.

BUTTERFLIES.—Linnaeus included all butterflies under the single genus Papilio, but later writers have divided them into several well-defined families, and into numerous genera. The largest and most magnificent species belong to the Ornithoptera or "Bird-winged Butterflies," a genus of Papilionidae, whose wings, measuring fully 7 inches across, are of a velvety black and brilliant green colour, the latter in such species as Ornithoptera craesus being replaced by fiery orange, while the body is golden, and the breast crimson. They are distributed over the islands of the Malay Archipelago, reaching, according to Mr Wallace, their maximum of size and beauty in the Moluccas. The Papilios are a closely allied group, smaller in size but equally brilliant in the colour and form of their wings. They are exceedingly numerous and are widely distributed over both hemispheres. One species only is found in Britain, the handsome Swallow Tail (Papilio machaon) (Plate XXVII. figs. 1, 2), formerly abundant in many parts of England, but now confined to the fen districts of Cambridgeshire, Norfolk, and Huntingdon. When alarmed the larvae of this and of other species of Papilios protrude from the upper part of the neck a soft forked horn that usually diffuses a penetrating and unpleasant odour. One of the most elegant of exotic species is the Malayan Papilio memnon, with black and blue wings 6 inches in expanse, and with the edges of the hind pair gracefully scalloped. This butterfly, though common enough in collections has recently gained additional interest from the fact, discovered by Mr Wallace, of the remarkable variety in the form of the females, a variety which has led to their being described under several specific names. In one group the families resemble the males in shape, though differing greatly—as many female butterflies do—in colour. In another group they differ both in colour and in the form of the hind-wings. These, Mr Wallace says, are "lengthened out into large spoon shaped tails, no rudiment of which is ever to be perceived in the males or in the ordinary form of the females." He also found that in shape and colouring those tailed females when on the wing, closely resembled another butterfly belonging to a different section of the same genus, Papilio coön, which he considers is thus mimicked by the erratic females of Papilio memnon. Strange to say both forms of females are produced from the eggs of either form. The genus Parnassius, which seems peculiar to the Alpine or subalpine countries of Europe and the North of Asia, belongs also to the Papilionidae. One species, Parnassius apollo (Plate XXVII., fig. 3), has semi-transparent wings, spotted with black vermilion, and is common in most of the mountain ranges of Europe, where it forms a very striking object. The Brimstones (Gonepteryx), the Clouded Yellows (Colias, Plate XXVII. fig. 4), and the White Butterflies (Pieris, Plate XXVII. fig. 6), many of which are abundant in Britain, and the larvae of which in most cases make great among garden vegetables, belong to the family Pieriae, That the caterpillars of this group are not fatal to the very existence of certain of our most useful vegetables is due solely to the ravages of the ichneumon flies, the larvae of which are parasitic upon these caterpillars, to such an extent that in every hundred larvae of the common College Butterly, there are probably not more than two or three entirely free from the ichneumon fly (Microgaster glomerata), and few caterpillars so attacked ever reach maturity. The species belonging to the family Nymphalidae have only four legs fitted for walking, the anterior pair being rudimentary. They include the majority of the showy butterflies of temperate regions, as the Peacock Butterly (Vanessa io, Plate XXVII. fig. 9), conspicuous from the "eyes" on the upper surface of its wings. The brilliant colouring of the upper surface is in marked contrast to the sombre hues of the under, which give it when resting on the branch of a tree the appearance of a dried leaf, and so is to a considerable degree protective. The Fritillaries (Argynnis, Plate XXVIII. Fig. 2) have the under surfaces of the wings ornamented with shining silvery disks, and except a few tropical species, are the only butterflies which have the under surface more gaily coloured than the upper. The Purple Emperor (Apatura iris) is one of the largest and most striking of British species. It is a powerful flyer, frequenting the tops of the highest trees, and is thus difficult of capture unless when brought near the ground by the attraction of some putrid carcase. To the same family belongs Nymphalis jasius ( Plate XXVIII. Figs. 7 and 9), one of the most beautiful of European species. The Heliconidae ( Plate XXVII. fig. 7) are a family of South American butterflies, so numerous both in species and in individuals, and of such showy colours on both surfaces of the wings, as to form, says Bates, "a feature in the physiognomy of the forest compensating for the absence of flowers." Their wings are long and narrow they fly lazily, and might thus be supposed to be specially liable to the attacks of insectivorous animals. As already stated, such is not the case, these insects being apparently protected by the nauseous character of their juices. It is this group which is chiefly mimicked in South America, finding imitators in several species of Leptalis, a genus of butterflies belonging to the family Pieridae, also in several species of Erycinidae, and in no fewer than three genera of day-flying moths all belonging to edible groups. The family Morphidae (Plate XXVIII. fig.8) contains the largest and most splendid of the South America butterflies. Their wings, often 7 inches in expanse, are generally of a brilliant metallic blue, which, as the insect flies, flashes in the sunlight so as to be visible, it is said, a quarter of a mile off. They are found most abundantly in forest glades, through which they sail, only flapping their wings at considerable intervals at a great height, "seldom," say Bates, "descending nearer the ground than 20 feet." The Satyridae (Plate XXIX. Fig. 6) are found in every quarter of the globe, and seem equally at home on open plains, in forests, and on the slopes of mountains. Their larvae feed chiefly on grass, and have the almost unique habit of remaining concealed by day and of coming forth at night to feed. The Marbled White (Arge galathea) is the species oftenest met with in Britain. The Hetairae of Brazil, the wings of which are partly transparent, belong to this family. One of these, Hetaira esmeralda, says Bates, "has one spot only of opaque colouring on its wings which is of a violet and rose hue ; this is the only part visible when the insect is flying low over dead leaves in the gloomy shades where alone it is found, and it then looks like the wandering petal of a flower." The Hesperidae or Skippers (Plate XXIX. figs. 13 and 15), so called from their jerky hesitating mode of flight, show, in the thickness of their bodies, the only partially erect way in which they hold their wings when at rest, and the enclosure of their pupa in a cocoon, a distinct approach to the other great division of the Lepidoptera—the moths.

MOTHS.—The vast collection of species included under this term form eight principal groups, divided into numerous families.

1. The Sphingina or Sphinx Moths (Plate XXX. figs. 5 and 6), so called from the curious habit which the larvae have of raising the anterior segments of their bodies, and remaining motionless in this position for hours, thus bearing a fanciful resemblance to the fabled Sphinx, are for the most part crepuscular day-flying. They are also known in the type family as Hawk Moths from the strength and velocity of their flight. In common with the vast majority of moths they are furnished with a spine or strong bristle on the anterior margin of the inferior wings, which being received by a process of the under surface of the superior pair, maintains them in a horizontal or somewhat inclined position in repose. They are also usually provided with a greatly elongated tongue, with which they sip their food from flowers, and some species have the power of producing a humming sound. To this group belong the clear-wingled moths, Sesidae (Plate XXX. fig. 12) and Aegeriidae, all day-fliers, and looking more like the bees, wasps, and inchneumons which they are supposes to imitate, than moths ; also the family Uranaiidae (Plate XXIX. figs. 9 and 14), the species of which are among the most brilliant of Lepidoptera,—their wings being of velvety black, relived by numerous bars of golden green, and the inferior pair prolonged into an elegant tail, closely resembling the same appendage in many of the Papilios. They are all day-fliers, and this, together with their gay colouring and airy forms, led to their being at first classed among butterflies, a position which fuller acquaintance with them in the larva and pupa stages showed to be untenable. The typical species occur in tropical America, where they fly with amazing rapidity and perform annual migrations. The Death’s Head Moth (Archerontia atropos) is the largest of European Sphinges, and owing to the peculiar squeaking sound which it utters when alarmed, the death’s-head-like markings on the upper surface of its thorax, and its sudden appearance in districts where it may not have been noticed for years, it has for centuries been an object of superstitious dread to the uneducated. Its beautifully marked larvae feed upon the leaves of the potato, and burry themselves in the ground preparatory to undergoing metamorphosis. The Death’s-Head is fond of honey, in search of which is instinct leads it to enter hives, the inmates of which do not attempt to drive it out by means of their stings, but make every endeavour to raise a waxen will between the moth and their food stores. It is widely distributed over Europe, Asia, and Africa, while closely allied, but still larger forms occur in Australia.

2. The Bombycina (Plate XXX. figs. 14, 20–25) are nocturnal moths, with the organs of the mouth in many cases so atrophied as to be unfit for use. These lives but a few days, during which the male seeks the female and the latter deposits her eggs. They include the silkworm moths, so important to man from the silken cocoons in which they enclose their pupae. The silk-producing species are very numerous, but only a few of them have as yet been turned to useful account. The chief of these are the common Silkworm Moth (Bombux mori), a native of China, where its cocoons appear to have been utilized by man from time immemorial. During the 6th century it was introduced into Europe, where it soon flourished wherever the mulberry tree, the leaves of which are the sole food of the silkworm, abounded. On these the larvae feed for thirty days, after, which they begin to spin an oval cocoon of a close tissue of the finest silk, usually of a golden yellow colour, but sometimes white, and which when unravelled forms a continuous thread 1100 yards long. In orders to obtain a fresh supply of eggs, the silkworm breeder allows a few of the pupae to develop into moths ; and the female at once settles on the leaves provided for her, where she deposits her eggs and dies. The Arrindy Silkworm (Attacus cynthia), so called from the native name of the castor-oil plant on which its larvae feed, is a native of India. The coccon in very large, but the thread is too fine to be readily wound off, and it is therefore usually carded, the yarn being woven into a coarse silk cloth of great durability. The Tusseh or Tussur Moth (Antheraea mylitta) is also a native of Upper India, occurring abundantly in the jungles, where its cocoons, so concealed by the leaves as only to be detected by the presence of the dung of the larvae on the ground, are collected. The Tusseh silk is darker and coarser than that of the common silkworm, but resembles it in being readily wound off. In China there are two oak silkworms from which a coarse silk is obtained used for the clothing of the Chinese poorer classes ; but the most important of the oak-feeding species is the Yama-maï (Antheraea yama-maï) of Japan, the silk proudced from which was, at least until lately, reserved for the use of the Japanese imperial family. This moth is a beautiful insect, about 6 inches across the wings, of a brilliant golden-yellow colour, with a transparent or "eye" near the centre of each wing. Its cocoon is nearly as large as a pigeon’s egg, is of a silvery white within, although externally of a yellowish, green. In 1861 it was introduced into France where it now flourished, and there is good reason to believe, from the nature of its food and its hardiness, that the Yama-maï may yet be profitably reared in Great Britain. Tropaea luna, which feeds upon the liquid ambar trees in the southern parts of the United States, with wings of a lemon colour, each with a "transparent eye," and the hind pair prolonged into an elegant tail, is one of the loveliest species of Bombycina. Its cocoon is formed of the finest silk. Other well-known forms are the Eggars (Lasiocampa, Plate XXX. fig. 26) ; the Processional Moth (Cnethocampa processionea), so called from the habit its caterpillars have of congregating in companies of several hundreds, and of marching to their feeding-grounds in regular columns ; Vapourers (Orgyia, Plate XXXI. figs. 2, 3, 4), whose females being almost wingless deposit their eggs on the outside of their cocoons, and the Psyches (Psychidae), whose females in many cases have neither wings, legs, nor antennae, and never leaves the tubes in which they have passed the larva and pupa stages.

3. The Noctuina (Plate XXXI. figs. 9 and 14) form an exceedingly large group of nocturnal moths, although even here there are a few exceptional instances of day-flying species. They are distinguished by their stout bodies and narrow forewings, under which when reposing they conceal the inferior and in many cases more brightly-coloured pair. The majority of the species are small and dull in their colours, while a few are among the largest of known insects—the Great Owl Moth of Brazil (Erebus strix) measuring nearly a foot tip to tip of its wings.

4. The Geometrina (Plate XXXI. figs. 13 and 15) in the larval condition have only four prolegs, the usual number being ten, and in moving these are brought close up to the last pair of thoracic limbs, thus giving the caterpillar a looped appearance, hence the term "loopers" usually applied to these moths ; they hold on by the prolegs, an releasing those in front carry the body forward until the arched appearance is gone. They thus move by an alternate process of looping and straightening their bodies. The larvae of Geometers have also the curious habit of fixing themselves by their feet to the branch of a shrub, throwing the remainder of their bodies out, and remaining motionless in this position for hours, thus exhibiting an enormous amount of muscular energy. They are all protectively coloured, and in the attitude just described so resemble the surrounding twigs as to be readily mistaken for them. Geometers are to be found in sunshine and by night, in midsummer and at midwinter, the Early Moth (Hybernia rupicapraria) being caught in January.

5. The Pyralidina (Plate XXXI. figs 17, 19, 20, 23) are a group of small moths readily distinguished by their long slender bodies and large forewings. One of these, Pyralis vitis, is very destructive to vines, and another, Pyralis farinalis, feeds upon meal and flour. The Galleridae, a family Pyralidine moths, deposit their eggs in the hives of bees, where the caterpillars, enclosed in silken cases, devours the wax ; but the Hydrocampidae (Plate XXXI. fig. 12), which also belong to this section, are probably the most wonderful of all Lepidopterous insects, their larvae being aquatic, living ang feeding in water, and many of them breathing by gills similar to thus of caddisworms.

6. The Tortricina (Plate XXXI. fig. 16 include a great number of small moths exceedingly injurious to orchard and tress. They are known as "leaf-rollers" from the habit which most of their larvae have of rolling up the leaves on which they feed and thus forming a shelter for themselves. The Green Tortrix (Tortrix viridana) occurs in the larva state on the oak, to which it often does great injury by stripping the trees of their leaves in the month of June. Throughout Southern Europe the vine is liable to the ravages of another species, Aenectra pillariana, while few of our fruit trees, are except from the occasional attacks of some species or other of the Carpocapsidae, the fruit-eating family of this group.

7. The Tineina (Plate XXXI. figs. 21, 24, 25) contains the smallest of the Lepidoptera, and are best known as clothes moths. These clothe themselves at our expense in the warmest woolen garments, which they traverse in all directions, leaving behind a gnawed and worn-out path, so thin and bare as to yield to the slightest pressure. They also destroy furs, hair, feathers, and many other articles of domestic economy, and are the exterminating pests of zoological museums. To them we no doubt owe the destruction of the most perfect specimen of the Dodo known, which was one preserved in the Ashmolean Museum of Oxford. By means of their maxillae these little larvae shear down the surface of various substances, and uniting the particles by means of their glutinous silk, they thus form protecting habitations, which partake of the nature of the woolen or other stuffs on which the foresight of their parents has placed them. When they themselves increase in bulk, so as to find their abodes as inconvenient as a strait waistcoat, they split them down the middle, and interpose a piece proportioned, no doubt, to their expected as well as actual increase. They add to the length also by fresh materials to the anterior end. The Tinea granella lives in granaries, where it forms an abode for itself by enveloping several grains in a silken web. These it afterwards eats.

8. The insects of the remaining group, Pterophorina, are remarkable from the peculiar conformation of their wings. Each of these organs is split longitudinally into several branches, all of them delicately fringed. In the genus Pterophora (Plate XXXI. fig. 26) the fore wings are divided into two, and the hind wings into three branches ; while in Orneodes (Plate XXXI. fig. 27 each wing is split into six, and thee when the insect is at rest are folded together after the manner of a fan.

COLLECTION AND PRESERVATION OF LEPIDOPTERA.—Butterflies affect special localities with which it is well for the collector to make himself acquainted. A suitable hunting ground having been selected, the following apparatus is necessary:—a bag-net made of gauze or some equally light materials, with a wooden or metal ring and a handle, which may also be used a walking-stick, for capturing the specimens ; pill boxes into which to transfer them from the net ; and a wide-mouthed glass stoppered bottle, into which about forty leaves of the common laurel, bruised and cut into shreds, have been previously put. Exposure for a short time to the fumes arising from these shreds will cause the death for the inmates of the pill boxes. They may also be readily killed by pressing the thumb-nail against their thorax. For "setting" Lepidoptera, which if possible should be done before the insect stiffens, entomological pins are required, and these should be gilt in order to prevent the appearance of verdigris at the point where the pin enters the specimen ; also a setting-board, with an upper layer of cork, and having a groove in which to lay the body of the insect ; and small triangular strips of cardboard known as braces with which to set the wings. The process of drying should not be artificially hastened, as by exposure to heat the wings are certain to warp and the body to shrivel. Should the insect have stiffened before setting, or have been badly set, it can readily be softened again by placing it, as is done in the British Museum, in a shallow earthen vessel containing a layer of damp sand, and covering it with a close-fitting lid until sufficiently soft for resetting. Day-flying moths must be sought for in much the same way as butterflies, while nocturnal species may be regularly met with on the sallow, the honeysuckle, the lime tree, and the ivy, when these are in flower ; and when these and similar natural sources fail, the moth-collector has in sugar and light two admirable devices for securing specimens. A quantity of the coarsest brown sugar reduced by the addition of beer and water to a syrup, and to which a little run is added as required, is applied with a brush to the sheltered aspect of the trunks of trees on the outskirts of woods or in the neighbourhood of heaths. At nightfall the collector, lamp in hand, visits the sugared locality, and if the evening be favourable, that is, if it be warm and dull, he is almost certain to have his pains rewarded by an abundance of specimens, chiefly belonging to the Norctrina. Moths, it is well known, are readily attracted by light, and in a country or suburban house, in the vicinity of trees, a lamp placed outside an open window which is sheltered from the wind, another lamp in the interior of the room, will, if the might be close and dark, be almost certain to attract numbers of moths. Mr Wallace adopted this plan while collecting in Borneo, and he states that in what twenty-six nights he collected 1386 moths, "but that more than 800 of these were collected on four very wet and dark nights." In towns moths may often be caught flying about lamp-posts. In preserving the slit up their stout bodies and remove the contents, replacing these with wadding or paper. The drawers of cabinets containing Lepidoptera should be provided with a layer of cork and then papered, with a small bag of camphor attached to a corner to ward off the attacks of the dust-lice, or "mites" as they are usually, but incorrectly, called, the presence of which is made known by the appearance of a fine powder lying underneath the infected specimens. Insects in this condition should be thoroughly soaked in a solution of spirits of wine and camphor. The appearance of grease on thick-bodied moths is by no uncommon, but may be removed by dipping the insect in spirits of turpentine and embedding it in calcined magnesia till dry. The collector should be careful to keep a register of all his specimens, giving the localities where they were found, and recording any observations that may have been made at the time on their food, habits, &c. A small ticket attached to the pin of each specimen, and bearing its number in the register, is the best way of connecting the specimens in the cabinet with the entries in the register (J. GI.)




Search the Encyclopedia:



About this EncyclopediaTop ContributorsAll ContributorsToday in History
Sitemaps
Terms of UsePrivacyContact Us



© 2005-17 1902 Encyclopedia. All Rights Reserved.

This website is the free online Encyclopedia Britannica (9th Edition and 10th Edition) with added expert translations and commentaries