Social Life in the Insect World

by Jean-Henri Fabre

Would you, on the other hand, silence a living Cigale?—that obstinate melomaniac, who, seized in the fingers, deplores his misfortune as loquaciously as ever he sang the joys of freedom in his tree? It is useless to violate his chapels, to break his mirrors; the atrocious mutilation would not quiet him. But introduce a needle by the lateral aperture which we have named the "window" and prick the cymbal at the bottom of the sound-box. A little touch and the perforated cymbal is silent. A similar operation on the other side of the insect and the insect is dumb, though otherwise as vigorous as before and without any perceptible wound. Any one not in the secret would be amazed at the result of my pin-prick, when the destruction of the mirrors and the other dependencies of the "church" do not cause silence. A tiny perforation of no importance to the insect is more effectual than evisceration.

The dampers, which are rigid and solidly built, are motionless. It is the abdomen itself which, by rising and falling, opens or closes the doors of the "church." When the abdomen is lowered the dampers exactly cover the chapels as well as the windows of the sound-boxes. The sound is then muted, muffled, diminished. When the abdomen rises the chapels are open, the windows unobstructed, and the sound acquires its full volume. The rapid oscillations of the abdomen, synchronising with the contractions of the motor muscles of the cymbals, determine the changing volume of the sound, which seems to be caused by rapidly repeated strokes of a fiddlestick.

If the weather is calm and hot, towards mid-day the song of the Cigale is divided into strophes of several seconds' duration, which are separated by brief intervals of silence. The strophe begins suddenly. In a rapid crescendo, the abdomen oscillating with increasing rapidity, it acquires its maximum volume; it remains for a few seconds at the same degree of intensity, then becomes weaker by degrees, and degenerates into a shake, which decreases as the abdomen returns to rest. With the last pulsations of the belly comes silence; the length of the silent interval varies according to the state of the atmosphere. Then, of a sudden, begins a new strophe, a monotonous repetition of the first; and so on indefinitely.

It often happens, especially during the hours of the sultry afternoons, that the insect, intoxicated with sunlight, shortens and even suppresses the intervals of silence. The song is then continuous, but always with an alternation of crescendo and diminuendo. The first notes are heard about seven or eight o'clock in the morning, and the orchestra ceases only when the twilight fails, about eight o'clock at night. The concert lasts a whole round of the clock. But if the sky is grey and the wind chilly the Cigale is silent.

The second species, only half the size of the common Cigale, is known in Provence as the Cacan; the name, being a fairly exact imitation of the sound emitted by the insect. This is the Cigale of the flowering ash, far more alert and far more suspicious than the common species. Its harsh, loud song consists of a series of cries—can! can! can! can!—with no intervals of silence subdividing the poem into stanzas. Thanks to its monotony and its harsh shrillness, it is a most odious sound, especially when the orchestra consists of hundreds of performers, as is often the case in my two plane-trees during the dog-days. It is as though a heap of dry walnuts were being shaken up in a bag until the shells broke. This painful concert, which is a real torment, offers only one compensation: the Cigale of the flowering ash does not begin his song so early as the common Cigale, and does not sing so late in the evening.

Although constructed on the same fundamental principles, the vocal organs exhibit a number of peculiarities which give the song its special character. The sound-box is lacking, which suppresses the entrance to it, or the window. The cymbal is uncovered, and is visible just behind the attachment of the hinder wing. It is, as before, a dry white scale, convex on the outside, and crossed by a bundle of fine reddish-brown nervures.

1. THE ADULT CIGALE, FROM BELOW.
2. THE ADULT CIGALE, FROM BELOW.
3. THE CIGALE OF THE FLOWERING ASH, MALE AND FEMALE.

From the forward side of the first segment of the abdomen project two short, wide, tongue-shaped projections, the free extremities of which rest on the cymbals. These tongues may be compared to the blade of a watchman's rattle, only instead of engaging with the teeth of a rotating wheel they touch the nervures of the vibrating cymbal. From this fact, I imagine, results the harsh, grating quality of the cry. It is hardly possible to verify the fact by holding the insect in the fingers; the terrified Cacan does not go on singing his usual song.