The Life of the Grasshopper

by Jean-Henri Fabre

The secret of the sounds produced by the Decticus is out. The toothed bow of the left wing-case is the motor; the friction-nervure of the right wing-case is the point of concussion; the stretched membrane of the mirror is the resonator, to which vibration is communicated by the shaking of the surrounding frame. Our own music has many vibrating membranes; but these are always affected by direct percussion. Bolder than [[263]]our makers of musical instruments, the Decticus combines the bow with the drum.

The same combination is found in the other Grasshoppers. The most famous of these is the Green Grasshopper (Locusta viridissima, Lin.), who to the qualities of a handsome stature and a fine green colour adds the honour of classical renown. In La Fontaine she is the Cicada who comes alms-begging of the Ant when the north wind blows. Flies and Grubs being scarce, the would-be borrower asks for a few grains to live upon until next summer. The double diet, animal and vegetable, is a very happy inspiration on the fabulist’s part.

The Grasshopper, in fact, has the same tastes as the Decticus. In my cages, he feeds on lettuce-leaves when there is nothing better going; but his preference is all in favour of the Locust, whom he crunches up without leaving anything but the wing-cases and wings. In a state of liberty, his preying on that ravenous browser must largely make up to us for the small toll which he levies on our agricultural produce.

Except in a few details, his musical instrument is the same as that of the Decticus. It occupies, at the base of the wing-cases, a [[264]]large sunken surface shaped like a curved triangle and brownish in colour, with a dull-yellow rim. It is a sort of escutcheon, emblazoned with heraldic devices. On the under surface of the left wing-case, which is folded over the right, two transversal, parallel grooves are cut. The space between them makes a ridge which constitutes the bow. The latter, a brown spindle, has a set of fine, very regular and very numerous teeth. The mirror of the right wing-case is almost circular, well framed and supplied with a strong and prominent friction-nervure.

The insect stridulates in July and August, in the evening twilight, until close upon ten o’clock. It produces a quick, rattling noise, accompanied by a faint metallic clicking which barely passes the border of perceptible sounds. The abdomen, considerably lowered, throbs and beats the measure. This goes on for irregular periods and suddenly ceases; in between these periods there are false starts reduced to a few strokes of the bow; there are pauses and then the stridulation is once more in full swing.

All said, it is a very meagre performance, greatly inferior in volume to that of the Decticus, not to be compared with the song of [[265]]the Cricket and even less with the harsh and noisy efforts of the Cicada. In the quiet of the evening, when only a few steps away, I need little Paul’s delicate ear to apprise me of it.

It is poorer still in the two dwarf Dectici of my neighbourhood, Platycleis intermedia, Serv., and P. grisea, Fab., both of whom are common in the long grass, where the ground is stony and exposed to the sun, and quick to disappear in the undergrowth when you try to catch them. These two fat songsters have each had the doubtful privilege of a place in my cages.

Here, in a blazing sun beating straight upon the window, are my little Dectici crammed with green millet-seeds and also with game. Most of them are lying in the hottest places, on their bellies or sides, with their hind-legs outstretched. For hours on end they digest without moving and slumber in their voluptuous attitude. Some of them sing. Oh, what a feeble song!

The ditty of the Intermediary Decticus, with its strophes and pauses alternating at equal intervals, is a rapid fr-r-r-r similar to the Coaltit’s, while that of the Grey Decticus consists of distinct strokes of the bow and [[266]]tends to copy the Cricket’s melody, with a note which is hoarser and, in particular, much fainter. In both cases, the feebleness of the sound hardly allows me to hear the singer a couple of yards away.

And to produce this music, this insignificant and only just perceptible refrain, the two dwarfs have all that their big cousin possesses: a toothed bow, a tambourine, a friction-nervure. On the bow of the Grey Decticus I count about forty teeth and eighty on that of the Intermediary Decticus. Moreover, in both, the right wing-case displays, around the mirror, a few diaphanous spaces, intended no doubt to increase the extent of the vibrating portion. It makes no difference: though the instrument is magnificent, the production of sound is very poor.