Fig. 76.—a Leptus Autumnalis (nat. size). b Ditto (mag.).
To this tiny animal has been given the name of Leptus autumnalis; the first, on account of its extreme delicacy; the second, because it is visible up to the end of autumn.
When examined through a microscope, it produces on the spectator the impression of a spider; but, like all other insects, it has only six legs.
Our naturalists, however, have found some difficulty in classifying it; and by way of cutting the Gordian knot of their embarrassments, some have placed it in a separate family of Microphthiræ (literally "little lice"), which is made to include all Arachnidæ with six legs. Others, who regard the wheat worm as an insect, rank it among the parasitical Apteræ.
In effect, it has all the characters of the parasitical insect—its protracted head, distinct from the rest of its body, is sometimes thrust forward in quest of its food, sometimes drawn back or concealed, to protect it from danger. Intended to suck rather than to knead or bruise, it has a sucker, but no mandibles. The head is without antennæ, and its palpi are very short, barely visible, and of a conical form. The body is ovular and very soft (whence the Grecian name leptus, λεπτός, signifying "soft"). The anterior part, corresponding to the thorax, is broader than it is long, and is marked underneath, on each side of the central line, by a black point: these two points, symmetrically placed, appear to represent the eyes.
The posterior portion, corresponding to the abdomen, is longer than it is broad, and covered with hairs. Each leg consists of six joints, easily distinguished by the hairs inserted at each articulation; and each terminates in a couple of strong crooked claws, which enable the animal to obtain a firm hold on the skin.
Thus, then, to judge from the aggregate of its characters, the harvest bug, Leptus autumnalis, belongs to the class Arachnidæ, while the number of its feet places it in the class Insects. But this is a detail which causes little annoyance to a person being devoured by the "red beasts," and only anxious to rid himself of them.
But if such be his desire, let me tell him that the best remedies are bathing the afflicted part with lotions of vinegar, or rubbing it with sulphur ointment.
I have been asked whether certain tiny parasites, such as the Ocypete rubra,—which is also red, and has six feet like the Leptus autumnalis, but which, instead of attacking man and his domestic companions, attaches itself to flies,—I have been asked whether these insectiform Arachnidæ may not be species of larva not yet arrived at their matured condition.