Cocoon

“ Now, to begin with, a true cocoon is not solid to the core, as this one evidently is as we press it between our fingers, nor [148] can you pinch off a tuft of gray hair from the surface of an ordinary cocoon when you will. True, there are some cocoons into whose silk meshes the caterpillar weaves the hair of its body, but the felt thus formed is only a shell, and is intermeshed with silken webs, and one pinch alone will open up the hollow interior and show us the caterpillar or chrysalis within. ”

“ There is nothing lazy about him; and now he works with all his might, making his cocoon. He begins at the outside and shapes it like a particularly plump peanut of a clear, pale yellow. The silk is stiffened with a sort of gum as it comes out of the spinneret. The busy little worm works away, laying its threads in place in the form of a figure eight. For some time the cocoon is so thin that one can watch him. It is calculated that his tiny head makes sixty-nine movements every minute. ”

“ In my numerous entomological investigations I have always seen the larva’s industry and the mother’s thus making good each other’s deficiencies. In a deep, well-sheltered abode, the cocoon is of a light material; in a surface dwelling, exposed to the inclemencies of the weather, the cocoon is stoutly built. ”

“ In this habitation the little architect passes the winter secure from birds and other enemies. As soon as the cocoon has been completed, the caterpillar sheds its skin, and is transformed into a chrysalis. At first the leaf enveloping the cocoon remains green, but soon changes to a red or brown, when it becomes brittle, and is gradually carried away by the winds and storms of winter, until, finally, nothing remains except the cocoon itself, which is firmly suspended by the silk which once covered the footstalk of the leaf. ”

“ We may see them carrying little oval bodies carefully about: and these are the cocoons which they take to the top of the nest every morning, and back again at night. Most wonderful of all, they have an instinct which tells them when the perfect insect within the cocoon is ready to escape from its prison-house, and also that it is not strong enough to force its own way through. ”

“ The cocoon is globular, and the change from the nymph state to the imago is made in the cocoon, the structure of the mandibles of the pupa being peculiar, and specially adapted to the purpose of opening the cocoon. [387] The larvae of Ascalaphides, although so like the ant-lions in appearance, do not form pitfalls for the capture of their prey, but lurk under leaves on the ground, or under stones; they do not move backwards, but progress forwards in an ordinary manner; the habit of backward movement that we noticed in Myrmeleon being probably correlative with the habit of forming pitfalls. ”

“ We quit the worms at mid-day, when hardly a thread of this wonderful substance is as yet visible; we return early the next day, and the cocoon is formed, but it is yet too tender to be touched. The peasant merely contents himself with observing the shape and color of these cocoons—setting much store on such as are of a yellow brown tinge, small, with a belt in the centre. Some of the cocoons are as white as snow, some yellow, some brown. The peasant now reports the condition of the silk-worms to his masters who immediately places his seal on the door of the hoosse. ”

“ Proceeding onward, and protected from the fierce heat of the sun's rays by the pleasant shade of mountain pines, we were continually encountering horseloads of cocoons, the fruit of the industry of the Druse silk-rearer. The whole process, from hatching the silkworms' eggs till the moment that the worm becomes a cocoon, is one series of anxiety and labour to the peasant. The worms are so delicate that the smallest change of temperature exposes them to destruction, and the peasant can never confidently count upon reaping a harvest until the cocoon is fairly set. ”

“ Cocoon.—The last important spinning operation which remains to be described is the building of the so-called cocoon. This must be distinguished from the cocoon of insects, which is a protective covering of silk within which the larva assumes the pupa form. In the case of the Spider, the term is applied to the structure which serves to protect and conceal the eggs. It is often of considerable complexity, and is highly characteristic of the particular species which constructs it. ”

“ On breaking one of these lumps of mud, it is found to be a sort of pouch or cocoon, with thin walls, and with projections here and there corresponding to the form of the animal concealed within. Its larger end is rounded, but its narrower end is closed by a slightly convex lid with a narrow opening in the centre. If the surface of the cocoon be even gently touched, a pretty loud cry is heard which Natterer has compared to the mewing of a cat. ”

“ The cocoon in the different races presents characteristic differences; being large or small;—nearly spherical with no constriction, as in the Race de Loriol, or cylindrical with either a deep or slight constriction in the middle;—with the two ends, or with one end alone, more or less pointed. ”

“ More likely in every way is a migration when enclosed in the cocoon. The cocoons being small, and often deposited at the edges of ponds frequented by aquatic birds, there would be many chances of their being carried away with tolerable frequency ”

“ Consider, for instance, the concealment often brought by the cocoon—the selection of an appropriate situation, the building into the walls of a part of the surrounding surface, &c, &c. Upon the principle of "active mimicry," "the view would be, I suppose, that the ancestral larva spun a cocoon which was not much of a success, and was in consequence attacked by enemies; that the larva observed these attacks, and accordingly improved its cocoon. But that is not the way in which the struggle for existence is waged with insects. ”

“ Inside the cocoon the worm remains, adequately protected from cold and damp, for nine months. It emerges as a winged moth, whose sole function in life apparently is to lay eggs to produce more silkworms.
Spinning such a cocoon with its three quite different layers requires extreme precision of movement. Nature has not allowed for any possible variations. ”

“ The central ethereal cocoon shape, something between a cocoon and an open chrysalis in appearance, lightly suspended amid the grasses, is the bower or cradle. Seated on the upper left-hand edge with wing well displayed is an undraped fairy apparently considering whether it is time to get up. An earlier riser of more mature age is seen on the right possessing abundant hair and wonderful wings. ”

“ Once it has given out its first bit of silk, a worm in good health never stops, and the thread continues without interruption from one end to the other. You see that the cocoon is in reality a ball wound from the outside inward. ”

“ When the ant-lion larva is full grown it forms a globular cocoon by fastening together grains of sand with fine silk from a slender spinneret placed at the posterior extremity of the body; in this cocoon it changes to an imago of very elongate form, and does not emerge until its metamorphosis is quite completed, the skin of the pupa being, when the Insect emerges, left behind in the cocoon. ”

“ Within the cocoon are six to twenty ova, and these gradually mature and the young hatch out. When they leave the cocoon they are minute, and of the thickness of pack-thread. More than one cocoon is deposited by each leech, but unless the cocoons are anchored to some submerged object they often rise to the surface of the water and float half submerged, and are then apt to be destroyed by water-rats, voles, and other enemies of leeches. At times the leeches themselves destroy their cocoons. ”

“ One peculiarity as to their colour has attracted the attention of Réaumur and subsequent naturalists, namely, that in the case of many species a great change takes place in the colour during the life of the larva, and more especially at the period of the last moult. The change to the pupal state usually takes place in a cocoon, and some species have the peculiar habit of forming a double cocoon, the outer one being hard and coarse, while the inner is beautifully delicate. ”

“ You never hear caterpillars say, ‘I can’t do this, and will some one please help me to change my skin, or some one spin my cocoon for me?’ No, they do these things for themselves, and ask no advice about them either. Still I do believe one can’t be too careful about cocoons, for once you are in one and asleep you can’t defend yourself. It is much better to make them safe to begin with. That was what I thought when I made mine. I enclosed it in a leaf, and then to make sure the leaf wouldn’t fall in the Winter winds, I fastened it to a branch of the tree with a thread of silk. ”

“ These numerous cocoons attached to the twigs overhanging the stream in the still and biting winter day suggest a certain fertility in the river borders, impart a kind of life to them, and so are company to me. There is so much more life than is suspected in the most solitary and dreary scene. They are as much as the lisping of a chickadee. ”

“ Saw-flies, and some other Hymenopterous tribes, construct a double cocoon, the outer one not united to the interior, but inclosing it as the shell of a nut does its kernel. Many larvæ dwell in habitations which they form with much skill and labour, to defend their tender bodies, and these likewise serve as a ready and efficient protection for the pupa. ”

“ Not a place where a worm could climb or spin was unadorned, for the oval, shining cocoons, scattered like small, ripe fruit upon the twigs, made a delicate light on every side through the sombre dusk. ”

“ Whenever I see cocoons I am reminded of Yasuo Sakai. Of late I have become so completely a city-dweller that it is only by the patterns of autumn grasses on fabrics in the shop-windows that I know the autumn has come. No longer can I wander along country lanes where migrant crows drop seeds as they fly, the baskets of live cocoons swaying on the carts as if they would topple off at any minute. ”

“ Only those which are destined to become perfectly developed males and females attain the winged state. Before they assume the transitional or pupal condition, each spins around itself a slight but tough silken cocoon, in which it lies secure during the time which is consumed in developing its full perfection of form. ”

“ Two of the larvæ made their cocoons on the face of these corner sticks, which did not offer a surface of more than a quarter of an inch. One larva escaped into the room, and was afterwards found to have made its cocoon on the leg of an oak chair, or stool, I forget which. I think both these expedients are worth notice.—W. Oxenden Hammond (St. Albans Court, near Dover) . ”

“ Cocoons of tussock-moth and tiger-moth under bark, logs, and rubbish in early autumn.
Larvæ of the emperor-moth (cecropia) may be found wandering about, apparently aimlessly, in September; but they are searching for suitable places for attaching their cocoons to orchard and forest trees. [Pg 39]
After the leaves have fallen from shrubs and trees, cocoons can be found more easily on the naked twigs or in withered, rolled-up leaves that are fastened by the silk of the cocoon to the branches. ”

“ He is fairly plentiful around my place; even in the enclosure I find [299] his cocoon, which might easily be confused with that of the Oak Bombyx. I am deceived at first by the resemblance. Out of six cocoons, from which I expected to obtain Banded Monks, six females of the other species hatch at the end of August. Well, around those six females, born in my house, never a male appears, though there is no doubt that the tufted ones are present in the neighbourhood. ”

“ In fall and late summer are the best times to find cocoons, as birds tear open many of them in winter; and when weatherbeaten they fade, and do not show the exquisite shadings of silk of those newly spun. When fresh, the colours range from almost white through lightest tans and browns to a genuine red, and there is a silvery effect that is lovely on some of the large, baggy ones, hidden under bridges. Out of doors the moths emerge in middle May or June, but they are earlier in the heat of a house. ”

“ It is easy to find the cocoons these caterpillars spin, because they are the largest woven by any moth, and placed in such a variety of accessible spots. They can be found in orchards, high on branches, and on water sprouts at the base of trees. Frequently they are spun on swamp willows, box-elder, maple, or wild cherry. Mr. Black once found for me the largest cocoon I ever have seen; a pale tan colour with silvery lights, woven against the inside of a hollow log. ”

“ All cocoons are not alike. There exist, in fact, different races of silk-worms, as we have different races of dogs. These differences are less obvious in the animals themselves; they are best seen in the cocoons, which may be either white, yellow, green, or gray ”

“ When the work with the silk-worms is over, the queen presents her cocoons; and the tithe-tax of cocoons generally is collected, according to the number of mulberry trees; for noble and mean, for old and young there is one law. ”

“ The fine cocoons are strong, hard, and of a fine close grain; the larger, and of a more loose open grain; the double cocoons are those formed by two worms, the fibres cross each other, and renders them difficult to reel; the soft, thin, and coarse cannot be reeled. ”

“ Preserving Cocoons.–Gather the cocoons from the seventh to the tenth day, and spread them to dry. Select those intended for seed, strip off the floss, spread them out thin, and in two or three days the moths eat out. Each female lays about 450 eggs, on muslin or paper hung up. The moth in your silk cocoons, immediately kill, either by exposing to a hot sun under glasses, or by hiking in an oven not too hot, or suffocate the moth by burning charcoal in a close room ”