The Life of the Grasshopper

by Jean-Henri Fabre

THE LOCUSTS: THE LAST MOULT

I have just beheld a stirring sight: the last moult of a Locust, the extraction of the adult from his larval wrapper. It is magnificent. The object of my enthusiasm is the Grey Locust, the giant among our Acridians, who is common on the vines at vintage-time, in September. On account of his size—he is as long as my finger—he is a better subject for observation than any other of his tribe.

The fat, ungraceful larva, a rough draft of the perfect insect, is usually pale-green; but some also are bluish-green, dirty-yellow, red-brown or even ashen-grey, like the grey of the adult. The corselet is strongly keeled and notched, with a sprinkling of fine white worm-holes. The hind-legs, powerful as those of mature age, have a great haunch striped with red and a long shank shaped like a two-edged saw. [[402]]

The wing-cases, which in a few days will project well beyond the tip of the abdomen, are in their present state two skimpy, triangular pinions, touching back to back along their upper edges and continuing the keel of the corselet. Their free ends stand up like a pointed gable. These two coat-tails, of which the material seems to have been clipped short with ridiculous meanness, just cover the creature’s nakedness at the small of the back. They shelter two lean strips, the germs of the wings, which are even more exiguous. In brief, the sumptuous, slender sails of the near future are at present sheer rags, of such meagre dimensions as to be grotesque. What will come out of these miserable envelopes? A marvel of stately elegance.

Let us observe the proceedings in detail. Feeling itself ripe for transformation, the creature clutches the trelliswork of the cage with its hinder and intermediary legs. The fore-legs are folded and crossed over the breast and are not employed in supporting the insect, which hangs in a reversed position, back downwards. The triangular pinions, the sheaths of the wing-cases, open their peaked roof and separate sideways; the two [[403]]narrow strips, the germs of the wings, stand in the centre of the uncovered space and diverge slightly. The position for the moult has now been taken with the necessary stability.

The first thing to be done is to burst the old tunic. Behind the corselet, under the pointed roof of the prothorax, pulsations are produced by alternate inflation and deflation. A similar operation is performed in front of the neck and probably also under the entire covering of the shell that is to be split. The delicacy of the membranes at the joints enables us to perceive what is going on at these bare points, but the harness of the corselet hides it from us in the central portion.

It is there that the insect’s reserves of blood flow in waves. The rising tide expresses itself in blows of an hydraulic battering-ram. Distended by this rush of humours, by this injection wherein the organism concentrates its energies, the skin at last splits along a line of least resistance prepared by life’s subtle previsions. The fissure yawns all along the corselet, opening precisely over the keel, as though the two symmetrical halves had been soldered. Unbreakable [[404]]any elsewhere, the wrapper yields at this median point which is kept weaker than the rest. The split is continued some little way back and runs between the fastenings of the wings; it goes up the head as far as the base of the antennæ, where it sends a short ramification to the right and left.

Through this break the back is seen, quite soft, pale, hardly tinged with grey. Slowly it swells into a larger and larger hunch. At last it is wholly released. The head follows, extracted from its mask, which remains in its place, intact in the smallest particular, but looking strange with its great glassy eyes that do not see. The sheaths of the antennæ, with not a wrinkle, with nothing out of order and with their normal position unchanged, hang over this dead face, which is now translucent.

Therefore, in emerging from their narrow sheaths, which enclosed them with such absolute precision, the antennary threads encountered no resistance capable of turning their scabbards inside out, or disturbing their shape, or even wrinkling them. Without injuring the twisted containers, the contents, equal in size and themselves twisted, have managed to slip out as easily as a smooth, [[405]]straight object would do, if sliding in a loose sheath. The extraction-mechanism will be still more remarkable in the case of the hind-legs.

Meanwhile it is the turn of the fore-legs and then of the intermediary legs to shed armlets and gauntlets, always without the least rent, however small, without a crease of rumpled material, without a trace of any change in the natural position. The insect is now fixed to the top of the cage only by the claws of the long hind-legs. It hangs perpendicularly, head downwards, swinging like a pendulum, if I touch the wire-gauze. Four tiny hooks are what it hangs by. If they gave way, if they became unfastened, the insect would be lost, for it is incapable of unfurling its enormous wings anywhere except in space. But they will hold: life, before withdrawing from them, left them stiff and solid, so as to be able firmly to support the struggles that are to follow.