The Life of the Grasshopper

by Jean-Henri Fabre

The first Cicadæ appear at the time of the summer solstice. Along the much-trodden paths baked by the sun and hardened by the frequent passage of feet there open, level with the ground, round orifices about the size of a man’s thumb. These are the exit-holes of the Cicada-larvæ, who come up from the depths to undergo their transformation on the surface. They are more or less everywhere, except in soil turned over by the plough. Their usual position is in the driest spots, those most exposed to the sun, especially by the side of the roads. Equipped with powerful tools to pass, if necessary, through sandstone and dried clay, the larva, on leaving the earth, has a fancy for the hardest places.

One of the garden-paths, converted into a little inferno by the glare from a wall facing south, abounds in such exit-holes. I proceed, in the last days of June, to examine these recently abandoned pits. The soil is so hard that I have to take my pickaxe to tackle it.

The orifices are round and nearly an inch in diameter. There is absolutely no rubbish around them, no mound of earth thrown up [[27]]outside. This is invariably the case: the Cicada’s hole is never surmounted with a mole-hill, as are the burrows of the Geotrupes,[2] or Dorbeetles, those other sturdy excavators. The manner of working accounts for this difference. The Dung-beetle progresses from the outside inwards; he commences his digging at the mouth of the well, which allows him to ascend and heap up on the surface the material which he has extracted. The larva of the Cicada, on the other hand, goes from the inside outwards; the last thing that it does is to open the exit-door, which, remaining closed until the very end of the work, cannot be used for getting rid of the rubbish. The former goes in and makes a mound on the threshold of the home; the latter comes out and cannot heap up anything on a threshold that does not yet exist.

The Cicada’s tunnel runs to a depth of between fifteen and sixteen inches. It is cylindrical, winds slightly, according to the exigencies of the soil, and is always nearly perpendicular, for it is shorter to go that way. The passage is quite open throughout [[28]]its length. It is useless to search for the rubbish which this excavation ought, one would think, to produce; we see none anywhere. The tunnel ends in a blind alley, in a rather wider chamber, with level walls and not the least vestige of communication with any gallery prolonging the well.

Reckoned by its length and its diameter, the excavation represents a volume of about twelve cubic inches. What has become of the earth removed? Sunk in very dry and very loose soil, the well and the chamber at the bottom ought to have crumbly walls, which would easily fall in, if nothing else had taken place but the work of boring. My surprise was great to find, on the contrary, coated surfaces, washed with a paste of clayey earth. They are not by a long way what one could call smooth, but at any rate their irregularities are covered with a layer of plaster; and their slippery materials, soaked with some agglutinant, are kept in position.

The larva can move about and climb nearly up to the surface and down again to its refuge at the bottom without producing, with its clawed legs, landslips which would block the tube, making ascent difficult and [[29]]retreat impossible. The miner shores up his galleries with pit-props and cross-beams; the builder of underground railways strengthens his tunnels with a casing of brickwork; the Cicada’s larva, which is quite as clever an engineer, cements its shaft so as to keep it open however long it may have to serve.

If I surprise the creature at the moment when it emerges from the soil to make for a neighbouring branch and there undergo its transformation, I see it at once beat a prudent retreat and, without the slightest difficulty, run down again to the bottom of its gallery, proving that, even when the dwelling is on the point of being abandoned for good, it does not become blocked with earth.

The ascending-shaft is not a piece of work improvised in a hurry, in the insect’s impatience to reach the sunlight; it is a regular manor-house, an abode in which the grub is meant to make a long stay. So the plastered walls tell us. Any such precaution would be superfluous in the case of a mere exit abandoned as soon as bored. There is not a doubt but that we have here a sort of meteorological station in which observations are taken of the weather outside. Underground, fifteen inches down, or more, the [[30]]larva ripe for its emergence is hardly able to judge whether the climatic conditions be favourable. Its subterranean weather is too gradual in its changes to be able to supply it with the precise indications necessary for the most important action of its life, its escape into the sunlight for the metamorphosis.

Patiently, for weeks, perhaps for months, it digs, clears and strengthens a perpendicular chimney, leaving at the surface, to keep it sequestered from the world without, a layer as thick as one’s finger. At the bottom it makes itself a recess more carefully built than the remainder. This is its refuge, its waiting-room, where it rests if its reconnoitring lead it to defer its emigration. At the least suspicion of fine weather, it scrambles up, tests the exterior through the thin layer of earth forming a lid and enquires into the temperature and the degree of humidity of the air.

If things do not bode well, if a heavy shower threaten or a blustering storm—events of supreme importance when the delicate Cicada throws off her skin—the prudent insect slips back to the bottom of the tube and goes on waiting. If, on the other hand, the atmospheric conditions be favourable, [[31]]then the ceiling is smashed with a few strokes of the claws and the larva emerges from the well.