Chapter IV: Lepidoptera (4)

When the cocoons are completed, the people in charge of the rearing establishments separate them from the heather and sell them to the silk-spinners. But they must manage to get these cocoons into a state in which they will remain entire during a long time. They must, in other words, kill the chrysalis, to prevent the cocoons being pierced by the moth. To kill the chrysalis so as to prevent the development of the imago is an operation which is called the _étouffage_, or stifling.

To effect this stifling, the cocoons are exposed to a high temperature. Formerly, in the Cévennes, the cocoons were placed in a baker's oven, heated for baking bread. But they ran the risk thus of being burnt, or of a certain number of chrysalides remaining alive. Now, to kill the chrysalides, they make use of steam at 100°, produced by water boiling in a vessel, and which passes through wicker baskets filled with cocoons.

The rearer must also take care at the time he gathers them, to separate the cocoons which are to provide eggs for the next year. As the female cocoons are heavier than the male cocoons, they are easily separated by weighing them in a pair of scales.

To obtain the eggs, or grain, the cocoons are fixed on sheets of brown paper, covered with a slight coating of paste made of flour. They are arranged in such a manner that the moths shall find no obstacle when they come out of them, head foremost; and, moreover, so that they may be able to reach with their legs the cocoon which is opposite them, so as to hang on to it, and to facilitate their exit from their own cocoon (Fig. 218). The male and female cocoons are pasted on separate sheets.

It is from fifteen to twenty days after the _montée_, or _mounting_, and when the temperature of the rooms has been kept between 20° and 25°, that the moths begin to be hatched. As they appear, they are seized by the wings and placed on cloths stretched out for the purpose, where they are left for about an hour, till their wings have fallen flat on their bodies. As soon as they have evacuated a red liquor, the males and females, which up to that time have been apart, are put together.

They then stick sheets of paper on to screens, putting from twenty-five to thirty females on each sheet (Fig. 219). It is here the moths lay their eggs. The sheets of paper, covered with eggs, are then hung on wires, at a small distance from the ceiling of a room having a northern aspect, which is never warmed. They remain thus, exposed to all variations of temperature, till the return of the warm weather. We will say a few words, to bring this subject to an end, on the winding of cocoons and the spinning of silk.

The winding of cocoons is an operation which at first sight appears very simple, but which is in reality a difficult and delicate process. It requires unremitting attention, great experience, and a delicacy of touch which can only be found in the fingers of woman, or rather, in the fingers of certain women.

The woman who is spinning, stands before a sort of loom which is called _tour_ (Fig. 220). Under her hand is a copper containing water, which she heats to the required degree by opening the tap of a tube, which brings a current of steam. She plunges the cocoons into the hot water, and moves them about in it, to soften the gummy substance which sticks the silken threads of the cocoon together. Then she beats them, with a light hand, with a small birch-broom. The threads of the cocoons get caught in the extremities of the twigs of which the little broom is made, and the workwoman seizes with her fingers the bundle of threads, and shakes them about till she perceives that they are all single, and in a fit state to be joined together.

Let us suppose that it is wished now to make up a _brin_, or staple, by uniting together the ends of five cocoons. She chooses five ends in the mass, makes of these a bundle, and introduces it into the hole of a _filière_. She makes two staples (_brins_) at once, one on her right, the other on her left hand. She then brings them together, she crosses them, rolls them, and twists them, the one on the other, several times; after which, she separates them from above and keeps them well apart, making each of them pass into a hook at a distance, from which they are going to twist round into a hank, separately, on a wheel. The two threads thus twisted are drawn close together, compressed, and become one, getting round by rolling on each other, and being kept in continual motion, drawn out as they are by the rapid motion of the wheel.

The difficulty which the emptying the cocoon of its silk thread presents, makes us understand what difficulties those manufacturers must have met with who have lately attempted to extract from the stalks of mulberry leaves a sort of silk. We will enter into no details of the attempts which have been made to accomplish this object in our time, attempts which have, however, been crowned with no success whatever. We will confine ourselves to reminding the reader that these attempts are far from being of recent origination, since they date back to as far as Olivier de Serres, the father of French sericulture.

In a little work published by Olivier de Serres, in 1603, under the title of _Cueillette de la Soie_, "The Gathering of Silk," we find a memoir entitled: _La second richesse du mûrier, qui se trouve en son escorce, pour en faire des toiles de toute sorte, non moins utile que la soie provenant d'icelui_, "The second wealth of the mulberry tree which is found in its bark, how to make of it cloth of all sorts, not less useful than the silk derived from this tree." Olivier de Serres proves in this memoir that the second bark, or _liber_, of the mulberry tree contains a fibre capable of replacing hemp or flax, and he describes the processes by which this may be obtained. The processes which had been proposed by Olivier de Serres in 1603, were resumed in the Cévennes a dozen years ago by M. Duponchel on the one hand, and on the other by M. Cabanis,[64] who operated on the bark instead of taking the whole of the wood of the mulberry tree. But none of these attempts have given any good results up to the present moment.

[64] See the "Année scientifique," 7e année, p. 432.

The various diseases which for the last fifteen years have been so fatal to the mulberry silkworm, have suggested the idea of acclimatising in Europe other silk-producing Bombyces, if not with the view of superseding, at least as auxiliaries to the mulberry species. The genus _Attacus_ has furnished these auxiliaries. Among the species which have, in this respect, the greatest claims to our attention, we must place in the first rank those which feed upon the leaves of the oak tree. Indeed, the trees which can be made use of for their cultivation are very numerous in Europe, and, moreover, the silk produced by these worms appears to possess superior qualities.

There are three oak-feeding species of the genus _Attacus_. They are _Yama-Maï_, _Pernyi_, and _Mylitta_.

The silk of _Yama-Maï_ is as bright as that of the mulberry silkworm, but a little less fine and strong, and occupies the first rank after it. If we could succeed in acclimatising this species it would supply any deficiency there might be in our crops of ordinary silk.

The eggs of the _Attacus Yama-Maï_ were brought from Japan--where this worm is reared--conjointly with the mulberry silkworm, in 1862. The larvæ hatched at Paris, in 1863, were green, of a great size, remained in that state eighty-two days, and were easily reared. Their cocoon resembles that of the mulberry species. It is composed of a beautiful silk of a silvery whiteness in the interior, and of a more or less bright green on the exterior. The moth is very large and beautiful, of a bright yellow colour, approaching orange.

We give a drawing of the _Attacus Yama-Maï_, taken from the plates which accompany M. Guérin-Méneville's memoir.[65]

[65] Sur le Ver à Soie du Chêne, et son Introduction en Europe.
Extrait du Magasin de Zoologie, 1855, No. VI.

[For an account of experiments conducted in England by Dr.
Wallace, whichunfortunately were complete failures as far as
rearing the moth went, see an essay by that gentleman in _The
Transactions of the Entomological Society of London_, 3rd
series, vol. v., pt. 5; Longmans and Co. The results of an
experiment which give the greatest hopes of success, will be
found in "The Entomologist" for October, 1867.--ED.]

Fig. 221 represents the larva, or caterpillar, two-thirds natural size; Fig. 222, the cocoon, drawn on the same scale; and Fig. 223, the moth.

In 1866, M. Camille Personnat published a very interesting monograph of _Yama-Maï_, which may be consulted with profit by both cultivators of silk and naturalists.[66]

[66] Le Ver à Soie du Chêne (_Bombyx Yama Maï_), son histoire,
sa description, ses moeurs. 8vo., avec planches coloriées. A
Laval, à l'école de sériculture.

_Attacus pernyi_ yields a remarkably beautiful silk, fine, strong, and brilliant, which can be spun and dyed with great ease. The tissues obtained from it partake of the qualities of ordinary silk, of wool, and of cotton. This species of _Attacus_, which is reared on the oak in Mandchouria, has given rise to great hopes in France. The cocoons and moths of this worm were exhibited for the first time at the Universal Exhibition of 1855. They were reared by M. Jordan, of Lyons, from some cocoons sent over from China by the missionaries. It is much to be desired that this species may be acclimatised in Europe.

Figs. 224 and 225 represent, after drawings in the Memoir of M. Guérin-Méneville, already referred to, the cocoon and moth of the _Attacus pernyi_.

The silk which _Attacus Mylitta_ produces is perhaps superior to that of _Pernyi_. When the cocoons are properly prepared, the silk can with ease be wound off from one end of them to the other. This worm is found in various parts of Bengal and of Calcutta, and also at Lahore, and its silk is exported in considerable quantities under the name of _tusseh_. Brownish stuffs are made of it in India of firm and bright texture, which are used for summer clothing, or for covering furniture.

Figs. 226 and 227 represent the moth and the cocoon of _Attacus Mylitta_ after M. Guérin-Méneville.

In 1855 M. de Chavannes reared this species in the open air, near Lausanne, in Switzerland. This treatment succeeded perfectly, without any degeneration, for many years. It, however, died out at last, from the effects, perhaps, of too great a difference in the climate, or from those accidents, still so little understood, to which even the insects of our own country are subject. This was unfortunate, as this species is one of those whose acclimatisation in Europe is the most to be desired, for it would render great service to the cultivators of silk.

It remains for us to speak of two other species, which are very important, inasmuch as their domestication in Europe is now an accomplished fact. We mean the _Attacus_ or _Bombyx_ of the Ailanthus, and also that of the Castor-oil plant.

Every one has heard of the Ailanthus silkworm (_Attacus_ [_Bombyx_] _Cynthia_), whose acclimatisation in Europe has been materially assisted by the admirable and persevering efforts of M. Guérin-Méneville.

The Ailanthus worm is a native of Japan and of the north of China. It was brought over in 1858 by Annibale Fantoni, and sent to M. Guérin-Méneville by MM. Griseri and Colomba, of Turin. When it is nearly full-grown it is emerald green, with the head, the feet, and the last segment of a beautiful golden yellow, and has black spots on each segment. This worm, in its full-grown state, is represented by Fig. 228; in the same figure are also represented the eggs and the cocoon. The moth has the abdomen yellowish underneath, with little white tufts. Its wings are traversed by a white band, which is followed exteriorly by a line of a bright rose; each wing is also marked by a lunula or crescent-shaped spot.

In 1858 M. Guérin-Méneville presented to the Académie des Sciences of Paris the first moths and the first eggs laid in France of the _Attacus Cynthia_. This able entomologist demonstrated very soon afterwards--1st, that the caterpillars of this insect can be reared in the open air, and with scarcely any cost for management; 2ndly, that it produces two crops a year in the climate of Paris and the north of France; 3rdly, that the cultivation of the Ailanthus, or the false Japan varnish tree, on which this insect lives, is easy even in the most sterile soil.

M. Guérin-Méneville showed still further that _ailantine_, the textile matter furnished by the cocoon of the Cynthia, is a sort of floss silk holding a middle place between wool and the silk of the mulberry-tree worm, and which, as it can be produced at scarcely any expense, would be very cheap, and would serve for the fabrication of what are called fancy stuffs, for which ordinary floss silk is now used. In 1862 M. Guérin-Méneville sent in a Report to the Minister of Agriculture on the progress of the cultivation of the Ailanthus, and of the breeding of the silkworm, which was reared in the open air on this tree. He mentions, in his Report, the rapid development of the cultivation of the tree in France, the great number of eggs of the Ailanthus silkworm sold, the foundation of a model silkworm nursery at Vincennes, and, this one great point gained, that they had found out the way of unwinding the silk from the cocoons of the _Cynthia_ in one unbroken and continuous thread.

Till then European industry had only succeeded in drawing from the cocoons of the Ailanthus silkworm a floss silk, composed of filaments more or less short, obtained by carding, and unable to produce, when twisted, anything better than floss, that is to say, refuse silk. It is to the Countess de Vernéde de Corneillan, on the one hand, and to Doctor Forgemot on the other, that the merit is due of having obtained an unbroken thread of silk from the cocoon of _Attacus Cynthia_.

A monograph on the Ailanthus silkworm appeared in 1866 under the title, "L'Ailante et son Bombyx, par Henri Givelet."[67] It is a complete account of all the results obtained up to the time, both as regards the rearing of the silkworm and also as regards the cultivation on a large scale of the Ailanthus, or false Japan varnish tree.[68]

[67] In 8vo, avec plans et planches coloriées. Paris, 1866.

[68] A work by M. Guérin-Méneville on the same subject,
entitled, "Education des Vers à Soie de l'Ailante et du Ricin,"
in 12mo., Paris, 1860, may also be consulted.

[For a full account of successful experiments carried on in
England, see Dr. Wallace's essay in _The Transactions of the
Entomological Society of London_, 3rd series, vol. v., pt. 2;
Longmans and Co.--ED.]

The Castor-oil Plant Silkworm (_Attacus_ [_Bombyx_] _ricini_) is a species very nearly akin to the Ailanthus worm, perhaps only a variety, and comes from India. The silk which it produces is very similar in every respect to that of the _Cynthia_. The rearing of this worm could never attain to any great importance in France, on account of the necessity there is of renewing the plantations of the castor-oil plant each year. It would, however, afford an additional source of income to the farmers in the south of France, who cultivate the castor-oil plant with a view to selling its seeds, which are much used in pharmacy.

Nearly allied to the genus _Attacus_, which furnishes us with all these precious auxiliaries to the mulberry silkworm, are a great number of other species, both indigenous to Europe and exotic, mostly remarkable for their great size, and a few of which are common in this country.

Fig. 229 is the largest European moth, but never found farther north than the latitude of Paris. Its wings are brown, waved, and variegated with grey. Each of them has a large black eye-shaped spot, surrounded by a tawny circle, surmounted by one white semicircle, and by another of a reddish hue, the whole completely enclosed in a black circle. "These moths," says Geoffroy, "are very large; they look as if they were covered with fur, and, when they fly, one is inclined to take them for birds."

_Saturnia pavonia-major_ comes from a very large caterpillar, which is of a beautiful green, with tubercles of turquoise blue, each of which is surmounted by seven stiff divergent hairs. This caterpillar lives principally upon the elm, but it feeds also upon the leaves of the pear, plum, and other trees. It spins a brown cocoon, formed of a coarse silk of great strength. It is not until the following spring that it becomes a moth.

The Emperor Moth (_Saturnia carpini_, Fig. 230) much resembles the above, except in size. This species is common in England, and its green larva, covered with black or pink warts, from which spring hairs, as in the last, is by no means rare on heath in the autumn. It also feeds on bramble and other plants.

Among the _Attaci_ foreign to Europe, we must mention _Atlas_ (Fig. 231), the expanse of whose wings exceeds four and a quarter inches. This magnificent moth, one of the largest known, comes from China.

The family _Bombycidæ_ comprises many species which we must not omit to mention.

The Lackey (_Bombyx neustria_) derives its name from the colour of the caterpillar, which has longitudinal lines of various colours, and a blue head. These caterpillars live together on a great number of our forest and garden trees, to which they do much damage. The moth (Fig. 232) has a brownish body, and wings of a more or less tawny yellow colour, with two darker lines on the front wings.

The Procession Moth (_Bombyx processionea_) is a small greyish moth, the caterpillars of which live in numerous troops on oak trees, and devour the leaves at the moment of their development. In the evening these caterpillars come out of their common nest, and form a sort of procession; hence their name Procession Moth. "I kept some for a little time in my house in the country," says Réaumur. "I brought an oak branch which was covered with them into my study, where I could much better follow the order and regularity of their march than I could have done in the woods. I was very much amused and pleased at watching them for many days. I hung the branch on which I had brought them against one of my window shutters. When the leaves were dried up, when they had become too hard for the jaws of the caterpillars, they tried to go and seek better food elsewhere. One set himself in motion, a second followed at his tail, a third followed this one, and so on. They began to defile and march up the shutter, but being so near to each other that the head of the second touched the tail of the first. The single file was throughout continuous; it formed a perfect string of caterpillars of about two feet in length, after which the line was doubled. There two caterpillars marched abreast, but as near the one which preceded them as those who were marching in single file were to each other. After a few rows of our processionists who were two abreast, came the rows of three abreast; after a few of these came those which were four abreast; then there were those of five, others of six, others of seven, others of eight caterpillars. This troop, so well marshalled, was led by the first. Did it halt, all the others halted; did it again begin to march, all the others set themselves in motion, and followed with the greatest precision.... That which went on in my study goes on every day in the woods where these caterpillars live.... When it is near sunset you may see one caterpillar coming out of any of the nests, by the opening which is at the top, which would hardly afford space for two to come out abreast. As soon as it has emerged from the nest, it is followed by many others in single file; when it has got about two feet from the nest, it makes a pause, during which those who are still in the nest continue to come out; they fall into their ranks, the battalion is formed; at last the leader sets off marching again, and all the others follow him. That which goes on in this nest takes place in all the neighbouring nests; all are evacuated at the same time."

One part of Fig. 233 shows the arrangement of the caterpillars on coming out of the nest. These caterpillars are furnished with long hairs, slightly tufted, which come off with the greatest ease, and which if they penetrate into the skin, cause violent itching. In 1865 a number of the alleys of the Bois de Boulogne were shut up from the public in order to save them from this annoyance. These caterpillars construct a covering common to them all, in which they live, and transform themselves therein, each insect making for his own private use a small cocoon. This insect is said to have been found in England, but there is not sufficient evidence to admit it into our lists.

The _Orgyias_ comprise a great number of small species, of a dark colour, which do a great deal of damage to our forest trees. In September and October the male of the _Orgyia antiqua_, with his tawny wings, may often be seen flying about the streets of London. The female (Fig. 234) is remarkable, as she has only the rudiments of wings, and only goes as far as the side of her cocoon. The caterpillar of the _Orgyia pudibunda_, called also the Hop Dog, attacks almost every sort of tree. When the state of the atmosphere favours their propagation, they appear in fearful quantities, and cause the greatest havoc. During the autumn of 1828, in the environs of Phalsbourg, they were to be counted by millions. The extent of the woods laid waste was calculated at about fifteen hundred hectares. It is common in this country.

Among the genus _Liparis_, the species of which are also very destructive to trees, we must mention the Brown-tailed Moth (_Liparis chrysorrhoea_, Fig. 236), a species by no means rare in England. The caterpillars live in quantities, on apple, pear, and elm trees, and destroy the plantations of the promenades of Paris.

The females of this genus tear off the fur from the extremity of their abdomens to make a soft bed for their eggs, and to preserve them from the cold. And yet they are never to see their young, for they die after they have laid their eggs. Another tribe of _Bombycina_ contains species of a small size, which are remarkable from the habits of their caterpillars, which make, with foreign bodies, cases, in the interior of which they live and undergo their metamorphoses.

The caterpillars of the genus _Psyche_ live in a case composed of fragments of leaves, of bits of grass and straw, of small sticks of wood, or of little stones, stuck together, and intermixed with silky threads.

We give a representation (in Figs. 237, 239, and 240) of the cases of the caterpillars of three different kinds. The females of these moths are completely destitute of wings, and resemble caterpillars. As a general rule they hardly ever leave their case. The males (Figs. 238, 242) are of a blackish grey, and fly very swiftly.

The caterpillars of the genus _Hepialus_ are difficult to observe, as they live in the interior of the roots of various vegetables. Such is the common Ghost Moth (_Hepialus humuli_), which sometimes causes the greatest damage.

The type of the genus _Zeuzera_ is _Zeuzera æsculi_, or Wood Leopard (Fig. 243). It has white wings with large blackish blue spots on the anterior, and small black spots on the posterior wings. The caterpillar, of a vivid yellow, spotted with black, lives in the interior of the trunks of a great many trees, principally the chestnut, the elm, the lime, and the pear tree. This moth, which is known also by the name of Coquette, is to be seen in the evening flying about the public gardens of Paris, and is not rare in England. The most celebrated species of the allied genus _Cossus_ is the Wood-boring Goat Moth (_Cossus ligniperda_), figured in the opposite plate. The moth has a heavy brownish body and greyish wings streaked with black. It is found in most parts of Europe. The caterpillar is of a reddish colour, as if it had on a leathern jerkin, and disgorges a liquid which is believed to soften ligneous fibres, and it lives in the interior of willows and other trees. It was on this caterpillar that Lyonnet made his admirable anatomical researches.

Another tribe of _Bombycina_ comprises some very strange caterpillars, whose hindermost feet are changed into forked prolongations, which they move about in a threatening manner. These sort of fly-traps are perhaps meant to keep at a distance those insects which would lay their eggs upon the caterpillar's body. The caterpillars of _Dicranura_ are of this kind. We give a representation of the caterpillar and the moth of the Puss Moth (_Dicranura vinula_, Figs. 244, 245), as also the moth of the _Dicranura verbasci_, the former of which is common in England, and the larva may be found during the late summer and early autumn feeding on poplars and willows; and of the caterpillar of _Stauropus fagi_, the Lobster Moth (Fig. 247), rare in France, whose appearance is strange indeed. The moths, on the contrary, have nothing about them remarkable.

The _Noctuina_ are a group of Lepidoptera of middling size, and generally found in woods, meadows, and gardens, where their caterpillars have lived. They seldom fly till about sunset, or during the night. Their upper wings are of a dark colour, with spots in the middle of a particular shape. Their lower wings are of various colours, often whitish, sometimes red or yellow.

We give representations of some of the species of this group.[69] _Noctua tegamon_, Fig. 248; _Noctua nebulosa_, Fig. 249; _Noctua musiva_, Fig. 250; _Noctua brunnea_, Fig. 251; _Catocala fraxini_, Fig. 252; _Catocala Americana_, Fig. 253; _Catocala paranympha_, Fig. 254; _Catocala nupta_, Fig. 255, the Red Underwing; and _Erebus strix_, Fig. 256.

[69] In England it numbers about three hundred species. The
larvæ are of diverse habits, but the majority feed on low
plants; the moths are provided with a trunk, and are very
partial to sweets.--ED.

The bodies of these moths are robust and sometimes massive, and are scaly rather than woolly. The thorax is sometimes bristling with hairy tufts.

This genus includes 800 species, of which there are about 300 in France. The caterpillars of the _Noctuina_ are smooth or very slightly covered with hair, usually of a pale colour, and live on low plants, of which they devour, some the leaves, others the roots; then it is they are most destructive to agriculture. There are some of them which eat any caterpillars they may chance to meet, and even those of their own species, leaving nothing but the skin. Some of them surround themselves with a light cocoon before becoming chrysalides; others bury themselves in soft, well-pulverised soil.

The family of _Geometrinæ_, or Geometers, comprises moths of a middling size, and usually flying after sunset and during the night.[70] They frequent the alleys of damp woods, where they become the prey of the _Libellulæ_[71] and other carnivorous insects. Their bodies and abdomens are slender, their wings large, thin, fragile, often of a dark colour, with brilliant markings.

[70] few species fly in bright sunshine.--ED.

[71] Dragon-flies.--ED.

The caterpillars of the _Geometrinæ_ are known by the name of loopers or geometers. We have previously described their singular organisation. They are continually spinning a silken thread, which keeps them attached to the plant on which they live. If you touch the leaf which supports them they immediately let themselves fall.

"Nevertheless, they do not generally fall to the ground," says Réaumur; "there is a cord ready to support them in the air (Fig. 257), and a cord which they can lengthen as they will; this cord is only a very thin thread, but has nevertheless strength enough to support the caterpillar (Figs. 258, 259). All that there seems to fear is, that the thread may lengthen too quickly and the caterpillar fall, rather than descend gently, to the ground. But what we must first remark and admire is, that the caterpillar is mistress of its movements, and is not obliged to descend too quickly; it descends by stages; it stops in the air when it pleases. Generally it only descends at most about one foot at a time, and sometimes only half a foot or a few inches, after which it makes a pause more or less long, as it pleases." It is in this way that the caterpillars let themselves fall from the top of the highest trees: they remount again with no less ease.

Let us listen to Réaumur's description of the means employed by this caterpillar to ascend these heights. Figs. 260 and 261, drawn, as the three preceding ones, from the plates in Réaumur's Memoir, help us to follow the explanation given by the illustrious naturalist of the evolutions of our little acrobat:--"To remount," says Réaumur, "the caterpillar seizes the thread between its jaws, as high up as it can; as soon as it has done this it twists its head round, lays it over on one side, and continues to do so more and more every moment. Its head seems to descend below the last of the scaly legs which are on the same side as that to which it is inclined. The truth is, however, that it is not its head which descends, the part of the thread which it holds between its jaws is a fixed point for its head and for the rest of its body; it is that portion of the back corresponding with its scaly legs which the caterpillar twists upwards; the consequence is that the scaly legs and that part of the body to which they belong then ascend. When the last pair of legs is just over the jaws of the caterpillar, one leg, viz., that which is on the side towards which the head is inclined, seizes the thread and brings it over to the corresponding leg on the other side, which is advanced to receive it. If the head is then raised, which is done immediately, it is in order that it may seize the thread at a higher point than that at which it was caught at first; or, which is the same thing, the head, and consequently the whole body of the caterpillar, is found to have ascended to a height equal to the length of the thread which is between the place where its jaws seized it the first time and that where they seized it the second time. The first move in the upward direction is thus made, and the second soon follows.... If you were to seize the caterpillar on its arrival at the end of its upward journey, you would see a packet of threads huddled together between the four hindmost of the scaly legs. The greater the height ascended the greater is the size of this packet. All the turns of the thread which compose it are entangled. So the caterpillar does not consider it of any value. As soon as the insect can walk it gets rid of the mass, sets its legs free, and leaves it behind before one or at most two steps have been taken. The cord is wasted on each ascent, but the caterpillar can afford to lose as many as it likes, for it has in itself the source of the matter necessary for the composition of the thread, and it is a source from which that which was drawn off is being continually re-supplied. Moreover, spinning the thread costs the caterpillars but little; indeed, the loopers economise this thread so badly that most of them leave it behind them wherever they go."

They are found on many trees, but particularly on the oak, the foliage of which they often entirely devour. They burrow into the ground to change into chrysalides, and undergo all their metamorphoses in the course of the year. Others do not become perfect insects till the autumn, or sometimes not even till the following spring. A few assume the perfect state in winter. There are, indeed, some of these, such as the males of the _Hybernias_, which fly about on the foggy evenings of November. The females of this genus have either no wings at all, or else only rudimentary ones. Two species, the _Hybernia defoliaria_, or Winter Moth, and the _Chimatobia brumata_, abundant here, are very common in the environs of Paris.

M. Maurice Girard says, in his work on the metamorphoses of insects, that the females of these moths can easily be found at the beginning of November, in a very strange place, namely, on the gas lamps of the public promenades; for instance, along the roads in the Bois de Boulogne. No doubt they had climbed up to this height, attracted by the light, or perhaps had been carried thither by the males, which fly, having wings.

In February and March appear other analogous species. "We may find," says M. Maurice Girard, "near Paris, in the meadows which surround the confluence of the Seine and the Marne, at the end of the month of March, the _Nyssia zonaria_ (Fig. 267), the males of which insect remain during the day motionless on the grass."[72]

[72] With us this insect has a very limited range, being only
found at New Brighton, near Birkenhead, where it is most
abundant.--ED.

There are some species of this family in which the wings of the females are developed like those of the males.[73] Such are the Peppered Moth (_Amphidasis betularia_) and the Currant Moth (_Abraxas grossulariata_), whose caterpillar lives on the red currant and gooseberry, and an immense number known as Thorns, Carpets, Waves, &c.

[73] The exception is with those in which the wings are _not_
developed in both cases, and in England this peculiarity is
confined to species appearing during the winter and early
spring.--ED.

The section of the _Pyralina_ contains the smallest nocturnal Lepidoptera, and nearly all those tiny species which flutter round our lights in the evening.

Here are some drawings of a few of the numerous species of this section, remarkable for their small size and beauty:--_Penthina pruniana_, _Ædia pusiella_, _Xylopoda fabriciana_, _Poedisca autumnana_, _Tortrix roborana_, _Philobacera fagana_, _Tortrix sorbiana_, _Antithesia salicana_, _Poedisca occultana_, _Argyrolepia æneana_, _Sericoris Zinkenana_, _Sarrothripa revayana_, _Cochylis francilana_, _Choreutes dolosana_ (Figs. 268 to 281).[74]

[74] Many of these are placed by some authors among the
Pyralina, and by others among the Tortricina.--ED.

In a book of this kind we can only mention some types among these last insects, which claim our attention in what we might almost call a tyrannical manner. We will, therefore, content ourselves by saying a few words about the Green Tortrix, the Pyralis of the Vine, the Bee-hive Moth, some species of the Clothes Moth family (_Tineina_), and finally of the _OEcophoræ_.

The Green Tortrix (_Tortrix viridana_) has wings of a green colour, with the margin and fringe whitish on the anterior, and of an ashy grey on the posterior wings. The under-side of the four wings is of a bright white, as if it had been silvered. This pretty moth comes out in the month of May. It is so common everywhere, that at this season it is only necessary to shake the branches of the oaks which border the alleys of the woods to set in motion hundreds of them. The caterpillar is green, with black warty spots, each having a hair of the same colour. They are wonderfully lively, the moment they are disturbed taking refuge in a rolled leaf, which serves them as a dwelling-place. If they are pursued, they let themselves fall by the aid of a thread, and do not re-ascend till they think they can count on repose and security. This, and many kindred species, do a great deal of damage to our trees. They strip them of their leaves, and sometimes give them, during the first days of summer, the sad and melancholy appearance which they present in the middle of winter.

We have just alluded to the tube formed of a rolled leaf, in which the caterpillar takes refuge, and in which it lives. This tube it constructs itself. Réaumur has devoted a magnificent chapter of his Memoirs to observations on the skill with which divers species of caterpillars fold, roll, and bind the leaves of plants and trees, especially those of the oak. Let us listen to the great observer:--"If one looks attentively at the leaves of the oak tree towards the middle of the spring, many of them will be seen to be rolled in different ways. The exterior surface of the end of one of these leaves has, it appears, been rolled back towards the interior surface, in order to describe the first turn of a spiral, which is then covered by many other turns (Fig. 282). Some leaves are rolled towards their exterior surfaces, others are rolled towards their interior surfaces, but in a totally different direction. The length or axis of the first roll is perpendicular to the principal rib and to the stalk of the leaf, the axis of the latter parallel to the same rib (Fig. 283). Work of this kind would not be very difficult to perform for those who had fingers; but caterpillars have neither fingers nor anything equivalent to fingers. Moreover, to have rolled the leaves is only to have done half the work: they must be retained in a position from which their natural spring tends constantly to draw them. The mechanism to which the caterpillars have recourse for this second part of their work is easily perceived. We see packets of threads attached by one end to the surface of the roll, and by the other to the flat surface of the leaf. They are so many bands, so many little cords which hold out against the spring of the leaf. There are sometimes more than from ten to twelve of these bands arranged nearly in the self-same straight line. Each band is a packet of threads of white silk, pressed one against the other, and yet we must remember all are separate."[75]

[75] Mémoires pour servir à l'Histoire des Insectes, tome ii.,
page 210 (5e Mémoire).

Réaumur made the oak-leaf rollers work in his house. He has admirably described all their little manoeuvres, but we lack the space to convey to the reader the result of his minute observations. In fact, the leaf-rollers construct for themselves a sort of cylindrical cell, which receives light only through the two extremities. The convenience of this green fresh habitation is, that its walls furnish food to the animal which inhabits it. The caterpillar, thus sheltered, sets to work to gnaw away at the end of the leaf which it rolled first; it then eats all the rolls it has made, up to the very last.

Réaumur found also rolls which had been formed of two or three leaves rolled lengthwise, and he saw that the leaves which had occupied the centre had been almost entirely eaten. He saw also caterpillars which continued to eat while they were making their habitation. Let us add that one of the ends of the roll is the opening through which the caterpillar casts its excrement; that the caterpillar can prepare itself a fresh roll if it is turned out of the first; and, lastly, that it is in a rolled leaf that the caterpillar undergoes its metamorphoses into a chrysalis and into a moth.

Réaumur studied other leaf-rollers; for instance, those which roll the leaves of nettles and of sorrel. The last one works in a manner which deserves to be mentioned. Its roll is of no particular shape, but it is its position which is remarkable. It is set upon the leaf like a ninepin (Fig. 284). The caterpillar has not only to twist it up into a roll, but also to place it perpendicularly on the leaf.

Next to the rolling caterpillars, let us mention those which are contented with folding the leaves. These caterpillars then lie in a sort of flat box. Besides the rolling and folding caterpillars, there are still those which bind up a good many leaves in one packet. These packets are to be found on nearly every tree and shrub, and the caterpillar, lying nearly in the middle of the packet, is well sheltered, and surrounded by a good supply of food. We will content ourselves by giving a drawing, after Réaumur, of the pretty arrangement of the leaves of a species of willow (Figs. 285, 286). In the figures we see the parcel bound together by the caterpillar. In that to the right we see the transverse section of the packet of leaves magnified. At the two edges are seen the threads which keep the leaves together, and the cavity occupied by the caterpillar.

The Vine Pyralis is produced from a leaf-rolling caterpillar, which deserves our attention on account of the ravages which it has for some time committed, and which it still commits in vineyards. It was at the end of the sixteenth century that this pyralis first showed itself in the environs of Paris, in the territory of Argenteuil. "The inhabitants of this commune," writes the Abbé Leboeuf, "looked on the insects which spoiled their vines in the spring of 1562 as a visitation of God. The Bishop of Paris gave orders that they should offer up public prayers for the diminution of these insects, and that they should join to their prayers, exorcisms, without leaving the church." Prayers, processions, exorcisms, were again had recourse to in 1629, in 1717, and in 1733, to stop the ravages of this insect among the vines of Colombes, in the territory of Aï.

The country of the Mâconnais and the Beaujolais became in their turn the theatre of the ravages of the pyralis. These ravages very soon increased and spread. In 1836, 1837, 1838, this plague raged in the departments of the Saône-et-Loire, of the Rhône, of the Côte-d'Or, of the Marne, of the Seine-et-Oise, of the Charente-Inférieure, of the Haute-Garonne, of the Pyrénées-Orientales, and of the Hérault.

To give an idea of the losses which may be occasioned by the pyralis, in a period of ten years (1828-1837), twenty-three communes comprised in the two departments of the Saône-et-Loire and of the Rhône lost 75,000 hectolitres of wine a year, which may be valued at 1,500,000 francs. If we were to calculate the supply of articles of all sorts which this great number of casks of wine would have necessitated, the imposts on their transport, the duty, the taxes levied on their sale, the carriage by land and water, which would have brought receipts into the treasury, and lastly the diminution of taxes which had to be granted for seven years to the vine proprietors in the department of the Saône-et-Loire, and in 1837 in the department of the Rhône, and which amounted to a total of more than 100,000 francs, we shall find that the ravages of the pyralis caused in these two departments an annual loss of 3,408,000 francs, and as the visitation lasted ten years, we get the enormous sum total of 34,000,000 destroyed by the ravages of one species of insect. The moth of the pyralis (Fig. 287) shows itself from the 10th to the 20th of June. It is yellowish, more or less shot with gold. When at rest, its wings are folded back one over the other like a roof. Its flight is of short duration; it contents itself with going from one vine stock to another.

It is at sunset mostly that you see the moths of the pyralis fluttering about. They remain quiet during the day, particularly when the sun is at its hottest. They live on an average for ten days. The females lay their eggs--which are at first green, then yellowish, then brown--on the lower surface of the leaves.

The caterpillar of the pyralis (Fig. 288) is called, in vulgar parlance, according to the different places in which it occurs, vine worm, summer worm, vintage worm, shell. In the south of France it is called, in the patois of Languedoc, _babota_. Almost immediately after they leave the eggs, the little caterpillars hide themselves in the fissures of the vine stocks or the props which support them. They spin a small cocoon of a greyish silk, in which they remain curled up till the month of May. From the moment the leaves begin to develop they throw out threads here and there, entangling all the young shoots of the vine, which gives a desolate appearance to the vineyards. The leaves of the vine are their favourite food, but they attack the seeds of the grape also. As they increase in size every day, the damage they do goes on increasing, and has not reached the maximum of intensity till the moment when the caterpillars are about to change into chrysalides. They are then three-quarters of an inch long and of a yellowish green colour.

From the 20th of June to the 10th of July they seek shelter in the dry and interlaced leaves which have already served them for places of refuge and partly also for food, or else they make themselves a fresh nest.

At the end of two or three days, the caterpillar has become a chrysalis (Fig. 289), which in a short time assumes a brown colour. Shut up in the interior of the cocoon which the caterpillar had spun before undergoing its metamorphosis, it changes into a moth at the end of from fourteen to sixteen days.

The best way to diminish the ravages of the pyralis is to pluck off the leaves which are laden with eggs, and burn them, or bury them in deep holes.

Fig. 290, which we devote to the conspicuous insect whose destructive history we have been here able to sketch only slightly, gives all the particulars relating to this dangerous guest of the vineyards. On a branch of the vine may be perceived the pyralis in the caterpillar state, the eggs which have been laid by the moths, the chrysalides, and perfect insects. The eggs are shown at two periods of their development.

The Bee-hive or Wax Galleria is to be met with in all countries where bees are reared.

The moth (Fig. 291) hides itself during the day round about the bee-hives, and endeavours to make its way into them after sunset. The caterpillar is of a dirty white, with brown warty spots, each surmounted by a fine hair. It lives on wax, twines its threads round the honeycomb, and very soon causes the larvæ contained in it to perish.

When it emerges from the egg, which the female has laid in the honeycomb, the caterpillar makes for itself with the wax a round tube, in which it is safe against the stings of the bees. This tube, at first very small, is lengthened and enlarged as the caterpillar increases in size. It is generally from three to five inches in length. It is in the interior of this that the caterpillar constructs itself a hard cocoon, resembling leather, and it changes into a brownish chrysalis.

A species of the genus _Butalis_, the _Butalis_ or _Alucita granella_, is, in certain cantons of France, one of the greatest pests to agriculture. The caterpillar of the _Tinea granella_ undergoes its metamorphosis in the interior of grains of barley and of wheat, which it devours without being perceived from without. The female lays her eggs on the grains of corn before they are ripe. From four to six days after, the eggs are hatched, and the young caterpillars are hardly as thick as a hair. Each one takes possession of a grain of corn, and penetrates into it by an imperceptible opening. They eat the flower without injuring the teguments of the grain.

When it has attained its full size it spins itself a cocoon of white silk in the interior of the grain, which, after having been its lodging and its larder, becomes for some time its tomb. It has, however, taken care beforehand to make at the extremity of the grain a circular opening, through which the moth may come out when the grains have been threshed and stored up in the granary.

It is important to mention the _Tineina_, not because these little moths are beautiful--they are, on the contrary, very dingy--but because it is in this group that are found those insects which do the greatest damage to our crops. The moths of the genus _Tinea_ are very small. Their wings, which are greyish or brownish, are generally marked with whitish and yellowish spots or lines. These are the little moths which, in our houses, burn themselves so frequently in the flames of the candles.

Their caterpillars are small, voracious, and deserve, on account of the damage which they cause, to be compared to rats and mice. Furnished with powerful jaws, they destroy everything they find in their way, such as woollen stuffs, hair, furs, feathers, grain, &c.

The _Tineina_ are divisible into three groups: 1st, the species hurtful to our stuffs and furs; 2ndly, the species which destroy our corn crops; 3rdly, the _phytophagous_ species, that is to say, those which feed on plants.

In the first subdivision must be classed the Fur Moth, the Woollen Moth, and the Hair Moth.

The Woollen Moth is represented in the figure on next page. Its caterpillar has the form of a worm, and is of a glossy whiteness, with a few hairs thinly sprinkled over it and a grey line on its back. It is enclosed in a tube, or sheath, open at both ends, in the interior of which is a sort of tissue of wool, sometimes blue, sometimes green, sometimes red, according to the colour of the stuff to which the insect attaches itself and which it despoils. The exterior of this sheath is, on the contrary, formed of silk made by the insect itself, of a whitish colour.

The caterpillars are hardly hatched before they begin to clothe themselves. Réaumur observed one of these worms during the operation of enlarging its case. To do this it put its head out of one of the extremities of its sheath, and looked about eagerly, to the right and to the left, for those bits of wool which suited it best for weaving in. In Fig. 294, we see two larvæ occupied in eating a piece of cloth.

"The larva changes its place continually and very quickly," says Réaumur. "If the threads of wool which are near it are not such as it desires, it draws sometimes more than half its body out of its case to go and look for better ones farther off. If it finds a bit that pleases, the head remains fixed for an instant; it then seizes the thread with the two mandibles which are below its head, tears the bit out after redoubled efforts, and immediately carries it to the end of the tube against which it attaches it. It repeats many times in succession a similar manoeuvre, sometimes coming partly out of its tube, and then again re-entering it to fix against one of its sides a new piece of wool."

After having worked for about a minute at one end of its tube, it thinks of lengthening the other. It turns itself round in its tube with such quickness, that you would imagine it could not have had time to do so, and would think that its tail was formed in the same way as its head, and possessed the same address in choosing and tearing out the bits of wool.

Furthermore, when the moth which is working at elongating its case does not find the threads or hairs of wool to its taste within reach of its head, it changes its place. Réaumur saw this insect walking, at some speed even, carrying with it its case. It walks on its six front legs (Fig. 295). With the middle and hind legs it clings to the interior of its case.

At the same time that the larva becomes longer it becomes stouter. Very soon its garment will be too narrow for it. Will it enlarge its old coat, or will it make itself a new one? Réaumur discovered that it preferred to widen its old coat.