Part 13

The butterflies are included in the Lepidoptera, and are the day-flying forms. There are many other insects equally beautiful, in more subdued tints, which are night flyers. These are the moths (Fig. 237), which are slow of flight, ponderous, and have extraordinary tongues for sucking the juices from the flowers. They can be distinguished from the butterflies by their feathered antennæ. One of the best known for its ravages is the dwarf moth, the worm of which plays such havoc among woolens. The cankerworm moth is equally a pest among valuable shade trees. Another familiar form is the hawk moth (Fig. 238), which so resembles a humming bird in appearance and motion that it is almost impossible to distinguish between the two, the moth being one of the most active, poising over flowers and inserting its enormous tongue to secure the sweets there concealed. A showy moth is the huge Attacus, its larva being especially large and voracious.

The moths display as great a variety in their shapes, colors, and sizes as the butterflies. The death's-head moth (Fig. 239) is perhaps as startling as any, bearing on its back a well-defined figure of a skull. The most valuable moth to man is the silkworm moth, the wings of which have a spread of six inches and are a brilliant ochre yellow, fawn, or mouse color, marked with striking peacock-like eyes. They deposit eggs, but the development of the caterpillar is somewhat different from that of the butterfly larva. The latter passes its pupa stage as an unprotected chrysalis attached to some object by the tail (Fig. 240), but the caterpillar of the moth secretes silk from a gland in its head, and with this forms about itself a cocoon. This is unwound by machinery and woven into the valuable silk of commerce. The silk industry brings to the weavers of the United States alone an annual sum amounting to about $30,000,000. The silkworm can easily be kept and all its changes watched, and many persons are interested in rearing the worms. The time required by the worm to form its silk cocoon varies with the locality. Thus in France it will complete it in four days, while in England forty or more days are necessary. About two hundred cocoons weigh a pound.

Silkworm moths are ravenous eaters, living principally on mulberry leaves. They show much intelligence in forming their cocoons. Thus a South American moth (Fig. 241) forms a basketlike structure which it suspends from some limb. The cradle swings in the wind like a seed pod, more than anything else, and would never be suspected as inclosing a living creature. Many of the moths, by some remarkable instinct, deposit their eggs where the young will find an immediate supply of food. This care for their young is the cause of a vast amount of damage among fruit trees. The fruit moth, as an example, deposits its eggs in fruit; the caterpillar penetrates it and devours the interior, thousands of bushels of apples being destroyed yearly in this way, not to speak of other fruits.

One of the best known of the moths is the tent moth (Fig. 242), the larva of which forms a tentlike web for its protection in the trees it affects. A richly tinted flyer is known as the goat moth (Fig. 243), the caterpillar being a large and beautiful creature.

XXVIII. THE ANTS

If the question should be propounded which next to man is the most intelligent of animals, the reply might be, the ants; for after a careful study of all the ways and habits of these small insects, it will be very evident that the lives of many are conducted with more method than the lowest human lives.

The ants belong to the great group called Hymenoptera--insects with membranelike wings, including the gall flies, bees, and wasps.

Ants are found everywhere. Long lines are seen marching along, some coming, some going, in countless multitudes. Yet drop a strange ant into this highway and it is at once discovered and in danger. If water is poured into a nest of ants, the inhabitants come rushing out. Some come to fight, and others bear in their mouths the young (Fig. 244), countless thousands, to a place of safety.

The ant is a trim, vigorous individual, fleet of foot, tireless, never weary, brave, industrious, a type of the worker. The head is large. The eyes are compound, with three single eyes. The antennæ are long, slender organs by which ants appear to recognize friends or foes, and possibly talk with them in some way. Certainly when two ants meet, a very strange interchange of courtesies with the antennæ is performed. The males and females are winged, and there is a third kind without wings, called workers.

Ants live in vast communities of from one hundred thousand to five hundred thousand or more. They excavate the soil and gravel, descend into the ground, and tunnel it in every direction (Fig. 245). In certain places they store food, in others eggs. The affairs of their vast underground city are carried on with a marvelous method. Although the ants have wings, these are soon cast away. At certain times the winged males and females swarm out of the nest and fly away, forming other communities. The males soon die; the females rid themselves of their wings, and thereafter remain in their new nests. The entire work of the community falls upon the so-called workers. They make the nest, repair it, do the fighting when necessary, move the immature young or eggs, shut up the nest at night, and open it in the morning. The eggs are minute, and as soon as laid are taken by the workers, or nurses, as they are also called, and carried to favorable places, where they are carefully watched. They are shifted about and occasionally for some reason brought above ground. The larvæ, when they hatch (Fig. 246), appear as little worms, or grubs, which would starve if they were not constantly fed by the nurses. If it is too cold, these babies are taken up into the sunshine, or placed in some hall near the surface where the sun's rays can reach them. Finally they change to the pupa stage and are covered by a web. They are still cared for with the greatest solicitude by the nurses, which stand by when they finally hatch out and aid them in their entrance into the world. Nurses in every sense of the word, their care at this time is one of the most remarkable exhibitions of human traits in a lower animal known. Many other human traits find their prototype among these minute animals. They care for the young, the sick, and the wounded; they go to war, capture their foes, make slaves of them, and force them to work. They keep certain insects for the pleasant odor they afford and others for the secretions they emit, the latter action resembling keeping and milking cows. Ants build remarkable houses arranged in rooms for various purposes; they plant gardens to raise certain crops; they introduce plants that will provide certain food; they retard the growth of seeds in their granaries; build vast underground or covered roads to escape the heat; they make bridges to cross streams; and in numerous other ways they demonstrate their remarkable intelligence.

The extent of the homes of ants is astonishing when we bear in mind the size of the insect. Some often extend many feet underground, and their tunnels have been traced beneath the broad Paraiba River of South America.

Many different species of ants are known, all interesting for their singular ways of living. The foraging or slave-making ants of Africa go to war against other ants. Such foraging trips are carried on with remarkable discipline, and the warriors may be seen returning, a triumphant army, bearing the eggs and larvæ of the enemy, which they nurse and bring up as slaves. These slave makers are large and powerful Ecitons, the dominant race of the ants.

Among the slave-making ants the owners often become so dependent upon the slaves that they are almost helpless, and would starve were it not for these dependents. The so-called honey ants of Texas exhibit some remarkable traits in the manner of their lives (Fig. 247). These ants, which I have observed in the Garden of the Gods, Colorado, select certain individuals as storehouses and supply them with honey until the abdomen is expanded to many times its size, resembling a bottle. The ants when filled are placed in a compartment made for the purpose, and there hung to the wall, animated honey jars, which are taken down and made to give up their sweets as occasion demands. These honey balls are considered a delicacy in Mexico, and are served as dessert.

Among the ants, those of Texas known as the agricultural ants are remarkable for their intelligence. They are farmers, laying out places which they cultivate with a certain plant, which is especially to their taste, just as farmers plant corn.

XXIX. THE BEES AND WASPS

In almost every flower bed in the garden we shall find the bees, examples of tireless energy, storing up honey for their young in such vast quantities that the surplus forms a valuable food supply for man as well. The nests of bees are systematically robbed of their stores, and for this purpose the insects are supplied with artificial nests or hives, in which they deposit their honey, entirely for the benefit of mankind. Here we see a singular limitation placed upon intelligence. The intelligence of bees is wonderful and amazing. Many of their acts and works suggest those of human beings, yet when the time comes for thinking after the fashion of men, the bees are lacking. They go on storing honey in artificial hives without being able to bridge the mental chasm and perceive that they are being robbed and made to work as virtual slaves. Hence we assume that the intelligence of bees is not on the same plane as that of human beings. They appear to be acting upon a strong instinct which impels them to perform acts which seem intelligent.

The head of the bee bears two remarkable compound eyes, with three simple ones between them. The antennæ are short. The mouth parts (Fig. 248) are complicated, and adapted for sucking up the honey or sweets of flowers or the juices of fruits. In California, the bees eat fruit as well as honey, and even flesh or meat, in very dry seasons, when flowers are scarce. The abdomen of the bee (Fig. 249) is supplied with a sawlike stinger or dart (Fig. 250) which inflicts a painful and poisonous wound. In general appearance the ordinary honeybee resembles an ant with wings; but the bee is hairy, it has a sting, and the legs of the worker are provided with "honey baskets," which carry pollen.

Bees are of several kinds, queens, workers, and drones, there being a division of labor. The queen is the largest, the drone is the smallest, and it has no sting. The history of the bee and its development is one of the most wonderful chapters in the whole story of animal life. Glancing at the interior of a hive we see that the bees have constructed a series of hexagonal cells. To learn how they have accomplished this, we may follow a bee in its flight. This may be one or two miles from the hive, yet so perfect is the knowledge of the bee of direction, that it is rarely lost. Reaching a flower it sucks out the honey, which it swallows. It then takes pollen, the dust from the stamen of the flowers, and stows it away in little baskets attached to the legs. It also takes a waxlike substance called propolis from buds of various trees, which it packs with the pollen in the baskets. Arriving at the nest, the bee, with countless others, engages in the construction of the cells, which are of various sizes. The material for building up the cells is wax, which is secreted by the bees, appearing in little flakes under the abdomen, from which it is taken by the legs of the bee. This is the material from which the comb is made, while the propolis is employed as a cement to attach the cells together, and for various minor purposes. Think of thousands of workers bringing in this material, working in the dark, yet never making a mistake. The bee finally ejects the honey which it has swallowed, placing it in certain cells, where it is sealed up and remains until it is needed as food. The pollen is also placed in cells.

A single community of bees may consist of two hundred thousand individuals. In the hive there is a single queen, which often lays from fifteen hundred to two thousand eggs a day, and if we could follow her, we should find that she lays the eggs in different cells, and in cells of different sizes. In the first are eggs which develop into workers, and in the second are larger eggs which will produce males, called drones. The little eggs soon hatch into white grubs which are carefully fed by the workers with digested honey and pollen. Finally the young larvæ almost fill the cells and then stop eating. The workers cover them in, and each spins for itself a silken cocoon, in which it remains until it breaks out in the form of a perfect bee.

The workers build certain large cells on the side of the comb, which are called queen cells, and the larvæ which appear in them are fed with some peculiar food which produces queens. The workers watch each of these cells with great care, gnawing the wax away on top so that they can observe the progress of development. Finally a small hole is made, through which the proboscis of the young queen protrudes, and in this way it is fed for several days, during which it utters a low, piping noise. The queens attack each other on sight, and previous to the appearance of a young queen the old one, with thousands of followers, makes her escape, or swarms. Then the workers liberate a young queen, and if there are others, there are repeated swarms, each queen leaving with a multitude of followers, till the hive has but one queen. There are in the community now a number of drones, and as they appear to be an expensive and worthless burden to carry during the winter, the workers attack and kill them, throwing them out of the hive.

Among the many kinds of bees the carpenters (Fig. 251) are famous, boring tunnels into solid wood for the reception of their young; half an inch a day being accomplished by these little carpenters. The bumblebee, one of the largest, forms its nest in the ground (Fig. 252).

The wasps (Fig. 253) live in societies of males, females, and workers. The paperlike nests are familiar objects in the woods, resembling great bags of paper which when opened are seen to be filled with cells. Many nests are of beautiful shapes, resembling candelabra, while the cells of the common mud dauber (Fig. 254) call to mind the adobe houses of the Mexicans and Indians of the Southwest. The mud cells of a South American wasp resemble bottles (Fig. 255). Many of the large wasps are fierce and vindictive, and nearly all resent an attack upon their homes.

INDEX

Abalone, 109.

Æolis, 114.

Aeronaut, 179.

Agassiz, Louis, 27.

Amœba, 8, 10.