Homes Without Hands: Being a Description of the Habitations of Animals, Classed According to Their Principle of Construction - Page 32

The time occupied in the transaction necessarily varies, according to the size of the buried object and the condition of the beetle; but on the average an ordinary finch, or a mouse, can be buried in the course of a day. When the task is completed, a number of eggs are laid upon the buried animal, and then the beetles emerge, cover it with earth, and then fly away. In some cases they will bury a whole series of corpses; and in the well-known experiments of M. Gleiditsch, four beetles buried, in a small piece of earth, four frogs, three birds, two fishes, one mole, two grasshoppers, the entrails of a fish, and two pieces of meat. And so strong and persevering are these insects, that a single beetle succeeded in burying a mole in two days. Now the mole is at least forty times as large as the beetle, so that we can estimate the strength and perseverance of the beetle by calculating the labor which would be necessary for a man to inter, in two days, an animal forty times as large as himself.

Perhaps the reader may remember a curious analogy between the mode of sepulture employed by these beetles, and the mode of sinking wells in sandy soil. Instead of digging a hole, and then building a brick lining to it, a circular tower is first built, and then, by scraping away the sand from within, the workmen cause it to sink into the ground. When it has sunk sufficiently, some twelve or fourteen feet are added, and the sand again scraped out; and in this manner the brick tube sinks gradually down, and becomes the lining of the well.

THE beetle just mentioned conveys into its burrow the whole of the substance on which the grub is intended to feed; but those which we now shall examine select only a portion for that purpose. There is a very large tribe of beetles, of which the British type is the common DOR BEETLE (Geotrupes vulgaris), sometimes called the Watchman, or Clock, whose heavy hum drones upon the ear in the evening, as the

“Beetle wheels his drowsy flight,”

and whose hard and notched head occasionally strikes against the face with a violence less agreeable to the man than to the insect, the latter being quite undisturbed by the shock.

Catch one of these beetles, and examine the wondrous beauty of its color, how its polished surface gleams as if made of burnished steel, pure and bright as armor just out of the smith’s

BURYING BEETLE.

ANT-NEST.

hands. Yet this creature has, in all probability, been burrowing deeply into the ground, has been meddling with the most noxious substances, and still retains no trace of its past labors. Save for the round-bodied yellow parasites that cling to its body, and insert their beaks between the joints of its armor, it is brilliantly clear. Not a speck of mould remains upon its surface, not a stain defiles its limbs, neither does it retain the least odor which would betray its occupation. Other beetles are not so fortunate. The burying beetles just mentioned are mightily ill-savored insects, and so are many others with similar habits. But the Dor beetle is free from such noisomeness, and both the eye and the nostrils pronounce it pure.

Let us now watch this beautiful insect, as it wheels through the air. Either by the development of the sense of smell, or by some sixth sense with which humanity is practically unacquainted, the beetle is made aware that the object of its search is at hand. The dull, monotonous buzz is immediately exchanged for a triumphant hum, the circling flight ceases, and the beetle darts through the air, with arrow-like rapidity, to the spot which it seeks. A few more circles, lessening at every round, and down it settles, on an object uninviting to Europeans, but in great favor with Hindoos, Kaffirs, and scarabæi, namely, a patch of cow-dung.

No sooner has it settled, than it dives downward until it reaches the earth, and then bores a perpendicular hole, some eight inches in depth, and large enough to admit a man’s finger. I have often watched the beetles at their work, and seen them thus engaged, and have turned many a Dor beetle out of the burrow which it had been so industriously excavating. Having ascended to the surface, it carries a quantity of the cow-dung to the bottom of the burrow; deposits an egg, and ascends, repeating this process as long as its powers endure. There are several other British beetles which prepare the cradle for their offspring in a similar manner.

Merely to dig a hole, to place at the bottom of it the food which the young are intended to eat, and to fill it in with earth, is a process of great simplicity, and makes but few calls on the industry or ingenuity of the laborer. Some allied beetles there are, however, which feed their young on similar substances, and in like manner bury them in the earth, but which exercise extraordinary industry in the performance of the task. All the world has heard of the famous Scarabæus of the Egyptians (Scarabeus sacer), an insect which is found in many parts of the globe, and very much resembles the Dor beetle of our own country. This insect sets to work in a curiously systematic manner.

As soon as the sensitive organs of the Scarabæus announce to it that the desired substance is at hand, it proceeds to the spot, alights, and sets at once to work. First, it sinks a tolerably deep and perpendicular hole in the ground, and, having returned to the cow-dung, it separates a sufficient quantity for its purpose, lays an egg in it, and forms it into a rude ball. She, for the female insect is the worker, then begins a curious and laborious task. Seizing the ball between her hind feet, she begins to roll it about in the hot sunshine, not taking it direct to the shaft which she has sunk, but remaining near the spot. Should rain come on she ceases to roll, or should the ball be made just before sunset, she waits for the morning before recommencing her labor. The consequence of all this curious rolling about is twofold; it accelerates the hatching of the inclosed egg by the exposure to the sunbeams, and it forms a thin, hard, clay-like crust round the soft material in which the egg reposes.

When the ball is sufficiently rolled, it is taken to the hole, dropped down, and the earth filled in. The egg is very soon hatched, and from it proceeds a little white grub, which finds itself at once in the midst of food, and begins to eat vigorously. By the time it has devoured the whole of the contents of its cocoon—if the mere empty shell may be so called—it is ready for its change into the pupal form, and there lies in the earth until it again changes its form and becomes a perfect beetle.

If the reader will refer to the plate, he will there see two of these beetles at work upon a ball, for it is not an unusual circumstance that two insects should propel the same ball. And upon the accompanying illustration may be seen the completed cocoon. Several good examples of this cocoon are in the British Museum, as well as those belonging to allied insects.

Frequently the beetle is very much puzzled to discover a place wherein it may dig a hole for the reception of the ball, especially where the ground is uniformly hard. The material which it desires is generally to be found plentifully upon roads, but as roads are usually too hard to be penetrated by the beetle’s limbs, the unfortunate insects may be seen rolling their pellets with a patient and hopeless industry only to be equaled by that of Sisyphus. I may perhaps mention in this place that an allied species living in America is popularly called the tumble-bug—the latter inappropriate monosyllable being indiscriminately used for every insect that even looks like a beetle.

There is also in the British Museum one enormous cocoon made of clay. It is almost the size of a six-pounder cannon-ball, with walls of such thickness that the hollow in its centre is barely the size of a crab-apple. The weight of this cocoon is enormous, when the size of its inmate is considered, and that so comparatively small a beetle should construct and roll so large a ball seems almost incredible. The beetle belongs to the genus Copris. There is the cocoon of another species of Copris, but in this case the walls are very thin, and the entire ball would go into the hollow of that which has just been described. A British beetle, Geotrupes vernalis, also makes a cocoon about the size of that which has just been mentioned. It is made of mixed clay and cow-dung, and specimens may be seen in the Museum.

Cocoons of Scarabæus and Goliath.

Perhaps the most extraordinary of these cocoons is that which is represented in the illustration. This is made by one of the gigantic beetles of the tropics. The insect which made it has no English name, but is scientifically called Goliathus Drurii. This wonderful cocoon is as large as a swan’s egg, and, as may be seen by reference to the illustration, has very thin walls in proportion to its size. It is strengthened by a remarkable belt, which runs around its centre, exactly like that of the bullet which is used for the two-grooved rifle. How the belt is formed is perfectly unknown, as is its use, unless the strengthening of the walls be its only object. I have carefully examined the cocoon itself, and specimens of the insect which made it, and can find nothing which affords the least clew to the difficulty.

There is no doubt as to the species of insect which made it, for the creature lies inside, a small portion of the ends of the elytra and part of one leg being visible through the fracture. The color of the beetle is peculiarly beautiful, being rich dark chocolate, soft and deep as made of velvet, and upon the thorax and round the elytra are drawn broad streaks of creamy white. On account of the large dimensions of the cocoon, it has necessarily been reduced in size, but a common house-fly is introduced into the drawing, in order to show the comparative size of the cocoon and the insect.

Many of the Orthopterous insects are burrowers, either digging holes wherein they themselves reside, or preparing a subterranean habitation for their young.

The best known and most important of these insects is the MOLE-CRICKET (Gryllotalpa vulgaris), called in some places the CROAKER, or CHURR-WORM, on account of the peculiar sound which it produces. It is a truly wonderful insect—one of those beings which, for the sake of force, we may perhaps call the anomalies of nature, though, in fact, nature is perfectly harmonious, and can have no real anomalies. A cursory glance at the insect will at once point out its habits, for the general shape, as well as the strange development of the fore limbs, and the peculiar formation of the first pair of feet, are so similar to the corresponding members of the mole that the identity of their pursuits is at once evident.

Like the mole, the insect passes nearly the whole of its life underground, digging out long passages by means of its spade-like limbs, and traversing them with some swiftness. Like the mole, it is fierce and quarrelsome, is even ready to fight with its kind, and, if victorious, always tears to pieces its vanquished opponent. Like the mole, it is exceedingly voracious, and requires so much food, that if several of them be confined in the same cage and kept only for a short time without food, the strongest will fall upon the weakest, kill and devour them. Like the mole, also, it is useful enough in the fields, where its tunnels form a kind of subsoil drainage, but it is equally destructive in the garden, working great havoc among young plants and flowers. One species that inhabits Jamaica has done great damage to the young sugar-canes soon after they had begun to shoot up.

Page 32 of 120