AMERICAN LUNA MOTH.
Larva on Branch Below, and Cocoon on Twig Just Above.
In June the Lunas awake from their death-like slumber, burst asunder their silken cerements, having at first made loose the compact threads by a fluid-ejection, and come out into the world in all the freshness and glory of a new and untried existence. Their wings, which expand from four and three-fourths to five and one-half inches, are of a delicate light-green color, the hinder ones being prolonged into a tail of an inch and a half or more in length. Along the anterior margin of the fore-wings is a broad purple-brown stripe, extending also across the back, and sending downwards a little branch to a glittering eye-like spot near the middle of the wing. These eyes, of which there is one on each wing, are transparent in the centre, and encircled by white, yellow, blue and black rings. The hinder borders are more or less edged with purple-brown. All the nervures are very distinct, and pale-brown in color. Near the body the wings are thickly invested with long white hairs. The under sides, excepting that an indistinct line runs along the margin of both wings, are like to the upper. As for the body, the thorax is white, occasionally yellowish or greenish, and coursed by the purple-brown stripe that traverses the entire length of the upper edge of the wings; and the abdomen, similarly colored, and clothed with white, wool-like hairs. The head is small and white, and furnished with broad, flat and strongly pectinated antennæ, which are very much wider in the male. The legs are purple-brown, and poorly adapted for walking, but this defect is largely compensated for in the wide stretch of wings, that fit their possessor for powerful and long-sustained flight.
Such is Luna in her various transformations. Notwithstanding her great size and almost matchless loveliness, her habits are not proportionally noteworthy. The gift of superior beauty, in the insect as in the mammalian world, does not often carry with it a high order of intelligence. It is true the young Luna knows pretty well the secret of dissembling. How quickly she perceives the approach of an enemy! And she knows how to deal with him, but her little trick of simulating death, or an immobile twig, does not always succeed with the wily spider, or artful ichneumon. That she is a tolerably good connoisseur of the character of foods, there can be no question. You cannot deceive her. Take from her the foods her ancestors have used for centuries untold, and substitute others she knows nothing about, and she is at once cognizant of the change. However hungry she may be, and in her early growing years she is ever a voracious feeder, she will starve rather than eat what the unwritten law of her race has strictly interdicted. I have known cases where death has ensued, or the caterpillar has pupated earlier than usual, when alien food has been given it to eat. But in the beginning of life, just after the first skin-moulting has been effected, ere the little creature has attained its seventh day of age, no trouble is experienced in changing the food, almost anything edible in the plant-line being eaten, though some things with a more decided relish than others. In the matter of cocoon-weaving, where the necessary leaves for a basis cannot be obtained, as occurs in captivity, the inconvenience is overcome, but not without difficulty. Leaves, you must know, are in Luna’s way of thinking, as essential to cocoon-building as wooden or iron beams and girders to man’s own constructing. Without a framework of some sort, what a sorry attempt would we make at home-building, but Luna does succeed, after a good deal of wise planning and no little worry, in producing a house which is well worthy her effort.
While the gaudy moth or butterfly, when contrasted in wisdom and sense with the dingy-colored bee, may suffer in comparison, yet she is by no means the dull, stupid creature she is pictured to be. She lives, it is a fact, as has often been said, for the increase of her race, but the interest she shows for the young she may never see, in laying her eggs upon the plant that is to serve them as food and home, puts her upon a rather high plane of intelligent existence. Luna’s life, in the perfect state, is usually quite brief. It is one of the happiest of honeymoons. Love conquers and destroys all other passions of her being, while her gormandizing offspring are never troubled by the ardent flame which consumes even the thought of sipping the nectar of the flowers that rival in beauty the wings of the mother, who is the perfect representation and embodiment of elegance and grace. While the early insect lives and eats, the adult form, upon whom Dame Nature has expended so much wealth of color and such symmetry of shape, which make her a “thing of beauty and a joy forever,” lives and dies, for in her seeming haste and forgetfulness the great mother of us all has made her without the essential means of tasting food, a delight and an enjoyment which the lords of creation are so wont to esteem the purpose and aim of all human existence.
BASKET-CARRIERS.
You who have been to the country, in the summer, and who have kept your eyes alive to the surroundings, have doubtless seen the Basket-worm feeding upon the leaves of the quince, apple, peach, linden, and other deciduous trees, as well as upon such evergreen as the arbor-vitæ, Norway spruce, and red cedar. In Germany these worms are popularly designated Sack-träger, or Sack-bearer, while the mature insect is spoken of as the House-builder Moth. Scientifically speaking, the latter is called Thyridopteryx ephemeræformis, a name which is nearly twice the length of the caterpillar it represents.
During the winter the curious weather-beaten bags of these worms may be observed hanging from the tree-branches, apparently without a trace of the odd-looking creatures that hung them there the autumn before. If a number of these bags are gathered and cut open at this time, many of them will be discovered to be empty, but the greater portion will be found partly full of yellow eggs. Those which do not contain eggs are male bags, and the empty chrysalis of the male will be found protruding from the lower extremity. Upon close examination these eggs will be observed to be obovate in form, soft and opaque, about one-twentieth of an inch in length, and surrounded by more or less fawn-colored silky down. If left to themselves, they hatch sometime in May, or early in June.
The young which come from these eggs are of a brown color, very active in their movements, and begin at once to make for themselves coverings of silk, to which they fasten bits of the leaves of the tree on which they are feeding, forming small cones that are closely adherent to the leaf-surfaces. As the larvæ grow, they augment the size of their enclosures or bags from the bottom, until they become so large and heavy that they hang instead of remaining upright, as they did at first.
By the end of July the caterpillars become fully grown. They are now exceedingly restless, and may be seen wandering from branch to branch by means of their true legs which are projected from the mouths of their baskets, to which they keep firm hold, or suspended from a branch of a tree by a long silken thread of their own manufacture. When very abundant, as they were in certain localities during the season just ended, they become a great nuisance, as one can hardly walk beneath the trees without being inconvenienced by a dozen or more dangling into his face.
Removed from the case at this stage of existence and closely examined, that portion of the body which has been covered by the bag will be seen to be soft, and of a dull brownish color, inclining to red at the sides, while the three anterior segments, which are exposed when the insect is feeding or travelling, will be found to be horny and mottled with black and white. The pro-legs on the middle and hinder segments, which are soft and fleshy, will show themselves fringed with numerous hooks, by which the larva is enabled to cling to the silken lining of its bag and drag it along wherever it goes. The external surface of the bag is rough and irregular, often presenting a beautiful ruffle-like appearance, which is due to the projecting portions of the stems and leaves which are woven into it. During their growing-period these caterpillars are slow travellers, seldom leaving the tree on which they were hatched. When about to change into chrysalids, they fasten their bags securely to the twigs on which they happen to be, and then undergo their change, the male chrysalis being very much smaller than the female, hardly one-third its size.