Fig. 5.—Antennæ of Butterflies.
Fig. 6.—Antennæ of Moths.
The antennæ proceed from two points close to the upper borders of the eyes. They are jointed organs, and are of very different forms in the various species of Lepidoptera. They are generally long, slender, and clubbed at the extremity in butterflies, but exhibit several minor points of difference which we shall have to note later on. In moths the antennæ are sometimes long, slender, and pointed. Some are thick, and more or less prismatic in form; while others are slightly or deeply pectinated or comb-like. The
antennæ of butterflies are always straight, or only slightly curved; and, although the insects can sway them bodily, they have no power to bend them, or to stow them away in any place of shelter. Moths, on the other hand, when at rest, are almost invariably found to have their antennæ snugly tucked under the wings, and brought so closely against the side of the head for this purpose that even the uncovered portion is often difficult to find.
There are two other prominent appendages belonging to the heads of the Lepidoptera. These are the labial palpi or feelers of the lips. They are generally easily seen, projecting forward on the under side of the head, sometimes so long and conspicuous as to give one the idea of a snout or long nose. The palpi are jointed—usually in three parts—are covered with scales, and often furnished with hairs or bristles.
Fig. 7.—Section of the Proboscis of a Butterfly.