The Life of the Grasshopper

by Jean-Henri Fabre

When the weather is calm and warm, about the middle of the day, the Cicada’s song is divided into strophes of a few seconds’ duration, separated by short pauses. [[65]]The strophe begins abruptly. In a rapid crescendo, the abdomen oscillating faster and faster, it acquires its maximum volume; it keeps up the same degree of strength for a few seconds and then becomes gradually weaker and degenerates into a tremolo which decreases as the belly relapses into rest. With the last pulsations of the abdomen comes silence, which lasts for a longer or shorter time according to the condition of the atmosphere. Then suddenly we hear a new strophe, a monotonous repetition of the first; and so on indefinitely.

It often happens, especially during the sultry evening hours, that the insect, drunk with sunshine, shortens and even entirely suppresses the pauses. The song is then continuous, but always with alternations of crescendo and decrescendo. The first strokes of the bow are given at about seven or eight o’clock in the morning; and the orchestra ceases only with the dying gleams of the twilight, at about eight o’clock in the evening. Altogether the concert lasts the whole round of the clock. But, if the sky be overcast, if the wind blow cold, the Cicada is dumb.

The second species is only half the size [[66]]of the Common Cicada and is known in the district by the name of the Cacan, a fairly accurate imitation of his peculiar rattle. This is the Ash Cicada of the naturalists; and he is far more alert and more suspicious than the first. His harsh loud song consists of a series of Can! Can! Can! Can! with not a pause to divide the ode into strophes. Its monotony and its harsh shrillness make it a most unpleasant ditty, especially when the orchestra is composed of some hundreds of executants, as happens in my two plane-trees during the dog-days. At such times it is as though a heap of dry walnuts were being shaken in a bag until the shells cracked. This irritating concert, a veritable torment, has only one slight advantage about it: the Ash Cicada does not start quite so early in the morning as the Common Cicada and does not sit up so late at night.

Although constructed on the same fundamental principles, the vocal apparatus displays numerous peculiarities which give the song its special character. The sound-chamber is entirely lacking, which means that there is no entrance-window either. The cymbal is uncovered, just behind the insertion of the hind-wing. It again is a dry, white [[67]]scale, convex on the outside and crossed by a bundle of five red-brown nervures.

The first segment of the abdomen thrusts forward a short, wide tongue, which is quite rigid and of which the free end rests on the cymbal. This tongue may be compared with the blade of a rattle which, instead of fitting into the teeth of a revolving wheel, touches the nervures of the vibrating cymbal more or less closely. The harsh, grating sound must, I think, be partly due to this. It is hardly possible to verify the fact when holding the creature in our fingers: the startled Cacan does anything at such times rather than emit his normal song.

The lids do not overlap; on the contrary, they are separated by a rather wide interval. With the rigid tongues, those appendages of the abdomen, they shelter one half of the cymbals, the other half of which is quite bare. The abdomen, when pressed with the finger, does not open to any great extent where it joins the thorax. For the rest, the insect keeps still when it sings; it knows nothing of the rapid quivering of the belly that modulates the song of the Common Cicada. The chapels are very small and almost negligible as sounding-boards. There [[68]]are mirrors, it is true, but insignificant ones, measuring scarcely a twenty-fifth of an inch. In short, the mechanism of sound, which is so highly developed in the Common Cicada, is very rudimentary here. How then does the thin clash of the cymbals manage to gain in volume until it becomes intolerable?

The Ash Cicada is a ventriloquist. If we examine the abdomen by holding it up to the light, we see that the front two thirds are translucent. Let us snip off the opaque third part that retains, reduced to the strictly indispensable, the organs essential to the propagation of the species and the preservation of the individual. The rest of the belly is wide open and presents a spacious cavity, with nothing but its tegumentary walls, except in the case of the dorsal surface, which is lined with a thin layer of muscle and serves as a support to the slender digestive tube, which is little more than a thread. The large receptacle, forming nearly half of the insect’s total bulk, is therefore empty, or nearly so. At the back are seen the two motor pillars of the cymbals, the two muscular columns arranged in a V. To the right and left of the point of this V gleam the two tiny mirrors; and the empty space is [[69]]continued between the two branches into the depths of the thorax.

This hollow belly and its thoracic complement form an enormous resonator, unapproached by that of any other performer in our district. If I close with my finger the orifice in the abdomen which I have just clipped, the sound becomes lower, in conformity with the laws affecting organ-pipes; if I fit a cylinder, a screw of paper, to the mouth of the open belly, the sound becomes louder as well as deeper. With a paper funnel properly adjusted, its wide end thrust into the mouth of a test-tube acting as a sounding-board, we have no longer the shrilling of the Cicada but something very near the bellowing of a Bull. My small children, happening to be there at the moment when I am making my acoustic experiments, run away scared. The familiar insect inspires them with terror.

The harshness of the sound appears to be due to the tongue of the rattle rasping the nervures of the vibrating cymbals; its intensity may no doubt be ascribed to the spacious sounding-board of the belly. Assuredly one must be passionately enamoured of song thus to empty one’s belly and chest in order [[70]]to make room for a musical-box. The essential vital organs are reduced to the minimum, are confined to a tiny corner, so as to leave a greater space for the sounding-cavity. Song comes first; all the rest takes second place.

It is a good thing that the Ash Cicada does not follow the teaching of the evolutionists. If, becoming more enthusiastic from generation to generation, he were able by progressive stages to acquire a ventral sounding-board fit to compare with that which my paper screws give him, my Provence, peopled as it is with Cacans, would one day become uninhabitable.