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

9C

III.

H E M I P T E R A.

The Hemiptera are particularly distinguished from other kinds _ insects by the form of their mouth, which consists of a beak, more or less long, composed of six parts: that is, of a lower lip, or sheath; four internal threads, representing the mandibles and jaws of the grinding insects, and which are the perforating parts of the beaks;. and, lastly, of the upper lip or labrum. Owing to this apparatus, these insects are essentially sucking ones, and chiefly nourish themselves with the juices of vegetables, which they draw up with their beak. The wings of the Hemiptera are usually four in number; in some species they are membranous and similar to each other, and in others the upper are of rather harder consistency than the lower ones. In general, the former are quite different from the lower wings, and are only membranous at the tip, whereas the other part is thick, tough, and coriaceous.

The Hemiptera are divided into two very distinct sections, The one is composed of insects whose beak grows from the forehead or upper part of the head, and whose anterior wings are half coriaceous and half membranous, having the base of a different texture from the extremity: these are the Heteroptera (eVe^os, different; Trreprff, wing). The other section is composed of those whose beak grows from the lower part of the head, and whose anterior wings are always of the same consistency throughout: these are the Homoptera (ofjuis, the same; nrepdv, wing). We are about to give the history of these two sub-orders. Heteroptera.

The insects formerly known by the general name of Bugs have been divided by Latreille into two large families, containing: the one

the GeocoriscB* or Land Bugs; the other the Bydrocoris(r,\ or A'ater Bugs. * From ytf, the earth, and Kopjs, a bug. f From i/8wp, water, and K6pi.s, a bug.

The land bugs consist of a great number of kinds, which, for the most part, are of little interest. We will only mention here the Fenfafor/iid(E, commonly known as Wood Bugs; the Lygm^ Bugs, properly so called; the Beduvii, and the Hydrometra.

The PaitatomidcE, which comprise many genera, include the wood bugs of most authors. They are to be found on plants and trees. I They fly quickly, but only for a short time.

The Ornamented Pcntatoma {Sirachia \Pentatomd\ ornata), known as the Red Cabbage Bug, is very commonly found on the cabbage, and on most of the cruciferous plants. It is variegated with red and black, and its colours are subject to numerous variations. The Grey Pentatoma {Raphigaster griseus), Fig. 69, is common throughout the whole of Europe. In autumn these bugs are frequently to be found on raspberries, to which they impart their disagreeable smell. They are also to be found in quantities on the mullein, when that plant is in flower. The upper parts of the head , are of a greyish brown, and are sometimes slightly purple. The coriaceous part of the hemelytra is of a purple tint, but the membranous part is brown. All these parts are covered with black spots, which Fig. 69.

are only to be seen with a magnifying-glass. The {Raphlgl^ur^g^teus). wings are blackish. The under part of the whole body and the feet are of a light and rather yellowish grey, with a. Gonsiderable number of small black spots. The abdomen is black above; and it is bordered with alternate black and white spots.

We have repeated here the description given of this bug by the illustrious Swedish naturalist, De Geer, because our young readers have most likely met with this insect, or will do so some day when gathering raspberries. The Grey Pentatoma, marked with black, yellow, and red, is to be found throughout the whole of Europe in cultivated fields and gardens, sometimes also on the trunks of large trees, especially ielms. This species, in common with the greater part of those which compose the group we are describing, emits a smell when irritated or menaced by some danger. At other times no odour will be noticed. Let us hear what M. Le'on Dufour says on this subject. " Seize the Pentatoma with a pair of pincers and plunge it into a glass of clear water; look through a magnifying-glass, and you will see innumerable small globules arising from its body, which, bursting on the surface of the water, exhale that odour which is so disagreeable. This vapour, which is essentially acrid, if it happens

to touch the eyes, causes a considerable amount of irritation. If one of these insects is held between the fingers, so as not to stop up the odoriferous orifices, and to cause this vapour to touch a part of the skin, a spot, either brown or livid, will ensue on that part, which lotions, though repeatedly applied, will at first fail to remove, and which produces in the cutaneous tissue an alteration similar to that which succeeds the application of mineral acids."

The disagreeable smell exhaled by different species of Pentatoma is the result of a fluid secreted by a single pear-shaped gland, either red or yellow, which occupies the centre of the thorax, and which terminates between the hind legs.

With the Syromastes, which are bugs of this same section, the secretion has, on the contrary, an agreeable smell, which reminds one of that of apples. Many kinds of Pentatoma are destructive to agriculture. Others, however, attack the destructive insects, and ought therefore to be carefully spared. We will mention in this case the Blue Pentatoma, which kills the Altica^ of the vine.

There may be observed, at the foot and about the lower part of trees, or at the base of walls exposed to the mid-day sun, groups of fifty or sixty small insects pressed close to each other, and often one on the top of the other, their heads in the direction of a centre point. They are red, spotted with black. In the neighbourhood of Paris the children call them " Suisses," probably on account of the red on their bodies, that being the colour of the uniform of the Swiss troops formerly in the service of France. In Burgundy the children call them ^^ petits cochons rouges.'' They will be found described in Geofiroy's " Histoire des Insectes," under the name of the Red Garden Bug. At the present day they are placed in the genus LygcEus.^ When the bad weather comes, these little " Suisses " take refuge under stones and the bark of trees to pass the winter. During the whole of that season they remain in a sort of torpid state. But in the first days of spring they revive, and resume their ordinary habits. They suck the sap of vegetables, piercing the capsules of divers kinds of mallows, and always keeping in the sunshine.

The Bug, popularly so called, or Bed Bug {Acajithia ledularia, or Cifnex lectularius, Fig. 70), a most disagreeable and stinking insect, abounds in dirty houses, principally in towns, and above all in those of warm countries. It lives in beds, in wood-work, and paper-hangings. There is no crack, however narrow it may be, into which it is unable to slip. It is nocturnal, shunning the light. "Nocturnum

• This species is Ly^antis militaris.—'Eii. f A genua of beetles.

foetidiim animal,'* says Linnaeus. Its body is oval, about the fifth of an inch in length, flat, soft, of a brown colour, and covered with little hairs. Its head is provided with two hairy antennae, and two round black eyes, and has a short beak, curved directly under its thorax, and lying in a shallow groove when the animal is at rest. This beak, composed of three joints, contains four thin, straight, and sharp hairs. The thorax is dilated at the sides. The abdomen is very much developed, orbicular, composed of eight segments, very much depressed, and easily crushed by the fingers. The hemelytra are rudimentary. It has no membranous wings. The tarsi have three articulations, of which the last is provided with two strong hooks.

" These animals," says Moquin-Tandon, Bed Bug {Acanthia lectularia) in his " Zoologie Medicale," " do not draw magnified. I up the sanguineous fluid by suction, properly I so-called, as leeches do. The organisation ;of their buccal apparatus does not allow of

•jthis. The hairs of the beak applied the one .1 against the other exercise a sort of alternate Fig. 71. Imotion, which draws the blood up into the Egg of Bug, magnified. iJ oesophagus, very much in the same manner I as water rises in a chain pump. This rising is assisted by the viscous ilnature of the fluid, and above all, by the globules it contains." The I part of the skin which the Bug has pierced, producing a painful , sensation, is easily recognised by a litde reddish mark, presenting in i its centre a dark spot. Generally a little blister rises on the point pierced, and sometimes, if the Bug-bites are numerous, these blisters become confluent, and resemble a sort of eruption. These disgusting insects lay, towards the month of May, oblong whitish eggs (Fig. 71), ihaving a small aperture, through which the larva comes out. The larva differs from the insect in its perfect state, in its colour, which is pale or yellowish. This insect exists in nearly the whole of Europe, although it is rare or almost unknown in the northern parts. The towns of central Europe are the most infested by this parasite, but those of the north are not completely free from its presence. The Marquis de Custine assures us that at St. Petersburg he found them numerous. It is found also in Scotland; is very rare in the south of Europe; and seldom seen in Italy, where it is, however, replaced by other insects more dangerous or more annoying.

It has been said that the Bug was brought into Europe from America; but Aristotle, Pliny, and Dioscorides mention its existence. It is certain that it was unknown in England till the beginning of the sixteenth century. A celebrated traveller, a Spanish naturalist, Azara, has remarked that the Bug does not infest man in his savage state, but only when congregated together in a state of civilisation, and in houses, as in Europe. From this he concluded that the Bug was not created till long after man, when, after many centuries had elapsed since his appearance on the globe, men formed themselves into societies, into republics, or little states.

The bug is not a gluttonous insect, always bloodthirsty; on the contrary, its sobriety is remarkable. It is only after a prolonged fast that it bites animals; and Audouin has stated that it can live a year and even two years without food.

From time immemorial a number of different means have been employed for destroying these insects; but in spite of all, nothing is more difficult than to get rid of them from wood-work and i)aper-hangings, when they have once infested them. In general, strong odours cause their death. And so, to rid oneself of these disagreeable guests, it has been recommended to use tobacco smoke, essence of turpentine, the fumes of sulphur, &c. Mercurial ointment and corrosive sublimate are also excellent means for their destruction; and for the same purpose the merits of a plant belonging to the order Cruci ferae, Lepidimn ruderale, have been much vaunted; and more recently still, the root of the Pyrethrum, a species of camomile, reduced to powder, and blown into the furniture or wood-work. This powder is known and employed at Paris under the name of ^^poudre insecticide ^ Tiiere are two other kinds of bugs [Acafithia) which attack men. The one is the Acanthia ciliata, y^hich has been found in the houses-of Kazan, and which differs from the bed bug not only in its form, but also in its habits. It does not live in companies, in the narrow