Homes Without Hands: Being a Description of the Habitations of Animals, Classed According to Their Principle of Construction
There is an allied insect residing in India, which measures about three quarters of an inch in length, and is of a fine polished green color. Scientifically, it is known as Sphex scutigera. The habits of this insect have been carefully watched by Sir J. Hearsey, K.C.B., who gave me much information respecting the method by which it prepares a habitation for its young. This species preys upon large spiders and cockroaches, and sometimes displays a wonderful amount of ingenuity in achieving its object.
One of these insects had captured a spider, which was too heavy to be carried through the air. The Sphex then dragged it to a little bank, dropped it into the water, and perched upon it, sitting there until it had been carried some distance down the water. Finding that the spider was sinking, the Sphex left it, and sat on a straw, which was floating down the stream, still, however, keeping company with its prey. After a while, the spider struck against the shore, and the Sphex then grasped it afresh, and tried to drag it along. The steep bank, however, baffled all its endeavors, and at last the industrious creature was obliged to leave the spider on the ground, and to go off in search of another.
The dark and sombre little bee called Mellinus arvensis is an excellent example of the burrowers. This insect preys on various flies, and packs away a large number of its victims in the burrow. The flies which it chooses are all swift of wing, whereas the Mellinus is rather a slow flyer, so that it can not take its prey by open assault, but is obliged to trust to craft. In order, therefore, to obtain its victims, the Mellinus watches some spot where flies most love to congregate, and walks to and fro as if it were quite unconcerned. It continues to run about in this manner until it comes close to a fly, when it springs upon the luckless insect, trounces it in its claws, and carries it off like a falcon with a partridge.
Six or seven flies are generally taken by the Mellinus, and as soon as the larva is hatched it begins to devour the fly which is nearest to the bottom of the cell. It eats them in succession, usually devouring six of the victims, consuming the softer parts only, and leaving the head, shell of the abdomen, part of the thorax, and the limbs. Ten days suffice for the completion of its feeding, and it then spins a tough, dark-colored cocoon, wherein it remains during the winter and part of the spring, changes into the pupal condition in the summer, and attains its perfect state at the beginning of autumn.
Another species of burrowers, Oxybelus uniglumis, has similar habits. Mr. F. Smith writes of it as follows: “I once observed several females running among the blades of grass which shot up from the surface of a little hillock upon which the sun shone and tempted various diptera occasionally to alight. The Oxybeli continued to run about, apparently unheedful of the flies, until, at length, the latter became somewhat accustomed to their presence; but when the Oxybelus came within five or six inches, it darted upon the luckless fly in the same manner as a cat springs upon its prey.” The burrows of this species are generally made in hard white sand.
The boldest of the British bee-burrowers is undoubtedly the insect which is called Philanthus triangulum, inasmuch as it provisions its nest with the common hive-bee, seizing the luckless honey-makers, and carrying them off to its nest. It is a very fierce-looking creature, with a large head and wide jaws, and has a suspiciously waspish look, owing to its yellow abdomen and black dots. It does not confine itself to the hive-bees, but seizes also the andrenæ and similar insects.
The members of the genus Cerceris are remarkable for the variable coloring of the species, and for the widely different insects with which they store their nests. Generally they prefer beetles, and, strangely enough, they often select those species which are not only small in body, but are furnished with very hard shells, so that the larva would seem to experience some difficulty in making a meal. Several beetles which Mr. Smith found in the cells of the Cerceris were so hard that he could with difficulty pass a pin through their bodies. Fortunately for agriculturists, the Cerceris generally selects the very beetles which are most injurious to vegetation, such as the various weevils and the turnip-fleas. Mr. Smith is of opinion that the shells of the beetles are softened by the dampness of the ground in which they lie.
In the accompanying illustration are shown the nests of two common species of British HUMBLE-BEE.
Bombus Terrestris.
<!-- pandi-media-anchor:figure-p162-o29-2435b57dc6c992a8 -->Bombus Lapidarius.
Both these species are burrowers, and sometimes make their nests at a considerable depth beneath the surface. The common HUMBLE-BEE (Bombus terrestris) generally makes its subterranean house in the side of some bank, and the nest is usually found at a depth of a foot or eighteen inches. Sometimes, however, in places where the soil is light and friable, the nest has been found at a very great depth from the surface, so that a perpendicular shaft of five feet in length has been required before the nest could be reached. In all probability, the bee has been aided by the burrow of a field-mouse, when the gallery has been of such a length.
The history of the nest is really a curious one.
At the end of autumn nearly all the Humble-bees die. The males invariably perish, but one or two of the females survive, and pass the winter in a state of hibernation. They do not select the nest for this purpose, convenient though the locality may seem, but hide themselves away singly in sheltered spots, such as the eaves of thatched barns, hollow trees, haystacks, or old ruins. When the sunbeams of spring gain warmth and strength, the sleepers awaken from their torpor, and immediately search for a spot wherein the new home may be excavated.
These bees, which are the Methuselahs of their short-lived race, may be seen in any warm spring day, flying about in all directions, prowling over every spare yard of ground, and settling here and there, as if to test the quality of the soil. They are very jealous of observation at this time, and if they think that they are being watched, will take instant offense and fly off with a quick, eager sound, very different from the steady, monotonous hum, with which they accompany their researches. To watch one of these insects in hopes of seeing her begin her labors, is an endless task, for she will never dig an inch of soil as long as she sees any suspicious object, and will often make her way under a thick tuft of herbage, and remain quietly in the retired nook until she fancies that the danger has passed away.
When, however, she has suited herself with a locality, she scrapes away the ground quickly, and when she has dug to a sufficient depth, she scoops out a small cavity or chamber, and therein constructs her first nest. There are but few cells at the beginning of the year, and these contain the first workers, who are intended to assist in constructing the enlarged nest. The larvæ are large, fat, white, round-bodied creatures, with little horny heads, and their bodies always slightly curved. When they have completed their feeding, each spins for itself an oval cocoon of coarse silk, rather irregular in shape, very soft, tough, and thick in consistency.
Herein they remain until they have attained their perfect state, when they gnaw a round piece from one end of the cocoon, just as a chicken chips off the top of the egg, and emerge into the nest. They do not venture out into the air for several days, the thick hair with which they are covered being all matted together, their wings soft and crumpled, and their limbs scarcely able to bear them. Two or three days are generally passed in the nest, and not until having gained their full strength do they venture out into the wide world. None but worker bees are developed for the first part of the year, the females and males not making their appearance until the summer weather has set in.
As may be seen from the illustration, the cells of the Humble-bee are not arranged in regular rows like those of the hive-bee, but are set carelessly side by side, mostly fixed together in groups of greater or lesser dimensions. Now and then a very little group of two or three cells is found, and single cells are occasionally to be seen, detached from the general mass.
This species is more prolific than any other, and the nests contain more individuals. Mr. Smith mentions that in one nest he found one hundred and seven males, fifty-six females, and one hundred and eighty workers, making a total of three hundred and forty-three inhabitants. Compared with the numbers that inhabit the hive, this may seem to be but a small amount; but when the reader takes into consideration the fact that the insects are very much larger than the hive-bee, and that the cells in which they are hatched and nurtured are not only of corresponding size but are also set very irregularly, so as to occupy a large amount of space, he will see that the cells which produced nearly three hundred and fifty Humble-bees must have formed very large groups, and that the cavity which contained them must have been exceedingly large in proportion to the size of the excavators.
As far as my own experience goes, there is little danger in unearthing and exploring the nest of the Humble-bee. Opinions differ greatly on this point, some practical observers saying that the bees are dangerous when irritated, and that they execute stinging vengeance on the disturbers of the home; while others report that the insects do not attack at all; and others, again, say that they attack, but that their stings cause so little pain as to excite no fear. I have opened many a nest of the Humble-bee, and never been stung by the inhabitants, though the bare hand might easily have suffered, as it was thrust into the chamber wherein the cells reposed.
The honey of the Humble-bee is peculiarly sweet and fragrant, but not suitable for general consumption, as many persons, myself among the number, are always attacked with severe headache after eating the contents even of a single cell. The color of Humble-bees is most variable, especially in the male sex—so variable, indeed, that Mr. Kirby, in his monograph of the British bees, has divided this insect into seven distinct species. As if to add to the difficulty of identifying the different varieties, bees of more than one species will sometimes be found in one nest.
The colors, however, of the present species are generally as follows: The female is nearly an inch in length, and the general color is black. The collar is orange-yellow; a band of the same hue is drawn near the second segment of the abdomen; the hinder edge of the fourth segment and the whole of the fifth segment are pale yellow, and the tip of the abdomen is naked. The worker is barely half the size of the queen, and is marked in a similar manner, except that white hairs are mixed with the yellow. The male is intermediate in size, between the female and worker, being about three fourths of an inch in length. The yellow is brighter than in the female, and the tip of the abdomen is covered with light tawny hairs.