To watch these frolics in the tops of the trees is hardly possible; let us try to observe them in captivity. Four pairs are collected in the morning and placed, with some twigs off the pine-tree, in a spacious; cage. The sight is hardly worth my attention; deprived of the possibility of flight, the insects cannot behave as in the open. At most I see a male from time to time approaching his beloved; he spreads out the leaves of his antennae, and agitates them so that they shiver slightly; he is perhaps informing himself if he is welcome. Thereupon he puts on his finest airs and exhibits his attainments. It is a useless display; the female is motionless, as though insensible to these demonstrations. Captivity has sorrows that are hard to overcome. This was all that I was able to see. Mating, it appears, must take place during the later hours of the night, so that I missed the propitious moment.
One detail in particular interested me. The Pine-chafer emits a musical note. The female is as gifted as the male. Does the lover make use of his faculty as a means of seduction and appeal? Does the female answer the chirp of her innamorata by a similar chirp? That this may be so under normal conditions, amidst the foliage of the pines, is extremely probable; but I can make no assertion, as I have never heard anything of the kind either among the pines or in my laboratory.
The sound is produced by the extremity of the abdomen, which gently rises and falls, rubbing, as it does so, with its last few segments, the hinder edge of the wing-covers, which are held firm and motionless. There is no special equipment on the rubbing surface nor on the surface rubbed. The magnifying-glass looks in vain for the fine striations usually found in the musical instruments of the insect world. All is smooth on either hand. How then is the sound engendered?
Rub the end of the moistened finger on a strip of glass, or a window-pane, and you will obtain a very audible sound, somewhat analogous to that emitted by the chafer. Better still, use a scrap of indiarubber to rub the glass with, and you will reproduce with some fidelity the sound in question. If the proper rhythm is observed the imitation is so successful that one might well be deceived by it.
In the musical apparatus of the Pine-chafer the pad of the finger-tip and the scrap of indiarubber are represented by the soft abdomen of the insect, and the glass is represented by the blade of the wing-cover, which forms a thin, rigid plate, easily set in vibration. The sound-mechanism of the Pine-chafer is thus of the very simplest description.
INDEX
A
Acorn-Weevil, see Elephant-Beetle
Ameles, see Mantis, the Grey
Anacreon, on the Cigale, 9
Ant, fable of the Cigale and the, 1-16
Devours the Cigale, 9
Robs the Cigale, 8