The Bug, popularly so called, or Bed Bug (_Acanthia lectularia_, or _Cimex 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 foetidum animal," says Linnæus. 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 antennæ, 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.
[Illustration: Fig. 70.--Bed Bug (_Acanthia lectularia_), magnified.]
[Illustration: Fig. 71.--Egg of Bug, magnified.]
"These animals," says Moquin-Tandon, in his "Zoologie Médicale," "do not draw up the sanguineous fluid by suction, properly so-called, as leeches do. The organisation of their buccal apparatus does not allow of this. The hairs of the beak applied the one against the other exercise a sort of alternate motion, which draws the blood up into the oesophagus, very much in the same manner as water rises in a chain pump. This rising is assisted by the viscous nature of the fluid, and above all, by the globules it contains." The part of the skin which the Bug has pierced, producing a painful sensation, is easily recognised by a little reddish mark, presenting in 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), having 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.