The Insect World: Being a Popular Account of the Orders of Insects

dold of small Phryganece^''' others of EphemercB^\ but the greater part of Tipidcer The Empidce have the trunk bent down, and resembHng the beak 3f a bird; but the Bornbylidce^ on the contrary, have the trunk extended straight in front.

The typical genus which has given its name to this latter group is easily to be recognised by the elegance of the fur which covers its body, the slenderness of its feet, and the length ot its wings, which extend horizontally on each side of the body.

Much more common in hot climates than in the North, these insects, the larvae of which are not yet known, take flight in the

middle of the day, when the sun's rays are hottest. They fly very fast, making a dull buzzing sound, and hover over flowers, from which they draw the juices without settling.

Fig. 2i^ represents the Boi7thyIius major ^ which is common enough throughout the whole of Europe. This insect is from four to six lines long, black, with yellow fur; the feet light yellow; and the wings have the edges bordered with a sinuous brown band.

The genus Anthj-ax, belonging to this family, has a diflerent form to Bombylius. The body is much less hairy; the trunk is short and concealed in the mouth; the wings, which are very large, are clothed, at least in the principal genus, in a garb of mourning, sufficiently Iremarkable, in which the combinations of black and white are admirably diversified. *' Here," says M. Macquart, *' the line which separates the two colours is straight; there it represents gradations, in other cases it is deeply sinuous. Sometimes the dark part shows transparent points.

or the glassy part dark spots. Th'is sombre garb, added to the velvet black of the body, gives the Anthrax a most elegant appearance;

• The insects produced from the caddis or case-worm.— Ed. t May-fly family.— Ed.

THE INSECT WORLD.

52 and while resting on the corolla of the honeysuckle and hawthorn tc suck the juice, forms a most striking contrast, and sets forth its beauty no less than that of those lovely flowers."

Anthrax sinuata is common in Europe.

The family of the SyrphidcB includes three remarkable types which we cannot pass over in silence. They are Vermileo^ VoluccUa and Hclophilus. Vermileo de Geeri (Fig. 37), which inhabits the central anc southern parts of France, is four or five lines in length. Its face is white; its forehead grey, bordered with black; the thorax of yellowish grey, with four brown stripes in the male; the abdom light yellow, spotted with black; and the wings glassy.

Fig. 37. — Vermileo de Geeri, Fig. 38, —A species of Volucella.

The larva of the Vermileo has a thin cylindrical body, capable of bending itself in every direction; a conical head, armed with two horny points; and the last segment elongated, flat, elevated, and terminated by four hairy tentacles; at the sides of the fifth segment may be observed a little angle, from which projects a horny retractile point. It is of very singular habits. It makes a small tunnel in the sand, having a conical mouth, where it waits, like the spider, immovable. As soon as an insect falls into the hole, it raises its head, and squeezing its prey in the folds of its body, devours it, and afterwards throws out the skin. It lives in this way for at least three years before attaining the perfect state.

The Vohccellce (Fig. 38) have a strong resemblance to the humblebee. Certain kinds make use and abuse of this resemblance to introduce themselves fraudulently into its nests, and to deposit their

53

DIPTERA.

;ggs therein. When these eggs have hatched, the larvae, which have he mouth armed with two mandibles, devour the larvae of their losts, the bees. This is the return

|:hey make for the hospitality they

lave received! The Hclophili (Fig. 39; deserve :o be mentioned here on account of the singular shape of many of their larvae. The head is thick, !leshy, and varying a little in form. But the point by which they are easily to be distinguished from most other larvae is, that they have always very long tails, sometimes, Fig. 39. — A species of Helophilus. indeed, out of proportion to the length of the body. Reaumur called these larvae " vers a queue de rat;" they are known in England as rat-tailed maggots, and their

Fig. 40. — Larvae of Helophilus.

habits are aquatic. Having placed some of them in a basin of water, Reaumur saw that they kept in a perpendicular position at the bottom of the basin, and parallel to one another, the extremities

of their tails being on the surface of the water. He then increased the depth of the water by degrees; and, as it got deeper, observed that the tail of each worm became longer. These tails, which at first were only two inches long, at last attained to five.

It will be remarked that the body of each worm does not exceed five lines in length. The tail is a pecuhar organ, by the aid of which the worm breathes, although its body may be covered by water to the depth of several inches. It is composed of two tubes, one of which shuts into the other, like a telescope. Reaumur calls it the breathing tube. It terminates in a little brown knob, in which, according to Reaumur, are two holes for the purpose oi receiving the air, and which have five little tufts of hair, which floa; on the surface of the water. When the time comes for the metn morphosis of these worms, they come out of the water and bury themselves in the earth; the skin then hardens and becomes a sor of cocoon. In this cocoon the insect loses the form of a worm, an( takes by degrees that of the pupa, which it keeps until circumstance-cause it to throw off its last coverings, and to appear in the winged state. What an eventful life! what a life full of changes and turns of fortune is that of these insects, which pass the first and longest period of their existence under water, another part of their life under the ground, and, finally, after having existed in these two elements, enjoy, high in the air, the pleasures of flight!

The third group of Brachycera is that of the DicJuEta; that is, those flies having two-fibred suckers. Among these are classed the CEstri, the Co/iopes, and the flies properly so called.

The genus CEstrus, the Gad, Bot-fly, or Breeze, comprises those formidable insects which attack the horse, the sheep, and the ox.'" The labours of Re'aumur, in his admirable Memoirs, and those of M. Joly, Professor of Zoology to the Faculte des Sciences de loulouse, who published some most valuable researches on this subject, in 1846, will guide us in the following brief explanation.

The following is the description given by M. Joly of the Gad-fly {CEstrus equi) represented in Figs. 41, 42, which are taken from a drawing which accompanies that naturalist's Memoirs.

The head of this insect is large and obtuse; the face light yellow, with whitish silky fur; the eyes blackish; the antennae ferruginous;

• Mr. Bates, in his interesting "Naturalist on the Amazons," mentions art CEstrus as occurring in those regions, which deposits its eggs in the human ilesh, the larva causing a swelling which resembles a boil.— Ed.

57 bIPTERA.

the thorax grey; and the abdomen of a reddish yellow, with black spots. The wings are whitish, not diaphanous, with a golden tint, and divided by a winding band of blackish colour. The feet are palish yellow. This species is found in France, in Italy, and also in the East,

Fig. 41.— Horse-fly, male {(Estrus Fig. 42.— Horse-fly, female {CEstrus {gasterophtlus) eqiti). {gasterophilus) equt).

especially in Persia, and rarely in England. During the months of fuly and August the CEstnis frequents pastures, and deposits its eggs chiefly on the shoulders and knees of horses (Plate I. ). In order to do this, the female suspends herself in the air for some seconds over the iplace she has chosen, falls upon it, and with her abdomen bent, sticks

ler eggs to the horse's hair by means of a glutinous liquid with vhich they are provided, and which soon dries. This is repeated at ery short intervals. It often happens that from four to five hundred ggs are thus deposited upon the same horse. Guided by a marvellous nstinct, the female CEstrus generally places her eggs on those parts )f the horse's body which can be most easily touched with the ongue, that is, at the inner part of the knees, on the shoulders, and 'arely on the outer part of the mane.

The eggs of the (Estrus, which are white and of conical form,

Fig. 43.— Eggs of the Gad-fly {CEstrus {gasterophilus) equt) deposited on the hairs of a horse.

dhere to the horse's hair, as shown in Fig. 43. They are furnished ith a lid, which at the time of hatching opens, to allow the exit of 1

the young larva, which takes place, according to M. Joly, about twenty days after they are deposited. In fact, it is not in the egg state, but really in that of the larva, that the horse, as we shall explain, takes into his stomach these parasitical guests, to which Nature has allotted so singular an abode. When licking itself, the horse carries them into its mouth, and afterwards swallows them with his food, by which means they enter the stomach. It is a remarkable fact that it is sometimes other insects, as the Tabania for instance, that by their repeated stinging cause the horse to lick himself, and thus to receive his most cruel enemy. In the perilous journey they have to

Fig. 44.— Portion of the stomach of the horse, and larvae of CEstrus (gasterophilus) equi.

perform from the skin of the horse to his stomach, many of th€ larvae of the CEstrus, as may be supposed, are destroyed, ground by the teeth of the animal, or crushed by the alimentary substances There is hardly one CEstrus in fifty that arrives safely in the stomacl: of the horse; and yet if one were to open a horse which had beer attacked by the CEstri, the stomach would be nearly always found t( have many of the larvae sticking to its inside. Fig. 44, taken from i drawing which accompanies M. Joly's Memoirs, represents the stat( of a horse's stomach attacked by the Gad-fly larvae.

The larvae are of a reddish yellow, and each of their segments i: armed at the posterior edge with a double row of triangular spines