Social Life in the Insect World

by Jean-Henri Fabre

Very much in the same way, but with far less delicate precision, the claws of the crayfish, at the period of the moult, withdraw the soft flesh of their double fingers from their stony sheath.

Finally the long stilt-like legs are free. They are folded gently against the furrowed thighs, thus to mature undisturbed. The abdomen begins to emerge. Its fine tunic-like covering splits, and wrinkles, but still encloses the extremity of the abdomen, which adheres to the moulted skin for some little time longer. With the exception of this one point the entire insect is now uncovered.

It hangs head downwards, like a pendulum, supported by the talons of the now empty leg-cases. During the whole of the lengthy and meticulous process the four talons have never yielded. The whole operation has been conducted with the utmost delicacy and prudence.

The insect hangs motionless, held by the tip of the abdomen. The abdomen is disproportionately distended; swollen, apparently, by the reserve of organisable humours which the expansion of the wings and wing-covers will presently employ. Meanwhile the creature rests and recovers from its exertions. Twenty minutes of waiting elapse.

Then, exerting the muscles of the back, the suspended insect raises itself and fixes the talons of the anterior limbs in the empty skin above it. Never did acrobat, hanging by the toes to the bar of a trapeze, raise himself with so stupendous a display of strength in the loins. This gymnastic feat accomplished, the rest is easy.

With the purchase thus obtained the insect rises a little and reaches the wire gauze, the equivalent of the twig which would be chosen for the site of the transformation in the open fields. It holds to this with the four anterior limbs. Then the tip of the abdomen is finally liberated, and suddenly, shaken by the final struggle, the empty skin falls to the ground.

This fall is interesting, and reminds me of the persistence with which the empty husk of the Cigale braves the winds of winter, without falling from its supporting twig. The transfiguration of the locust takes place very much as does that of the Cigale. How is it then that the acridian trusts to a hold so easily broken?

The talons of the skin hold firmly so long as the labour of escape continues, although one would expect it to shake the firmest grip; yet they yield at the slightest shock when the labour is terminated. There is evidently a condition of highly unstable equilibrium; showing once more with what delicate precision the insect escapes from its sheath.

For want of a better term I said "escape." But the word is ill chosen; for it implies a certain amount of violence, and no violence must be employed, on account of the instability of equilibrium already mentioned. If the insect, shaken by a sudden effort, were to lose its hold, it would be all up with it. It would slowly shrivel on the spot; or at best its wings, unable to expand, would remain as miserable scraps of tissue. The locust does not tear itself away from its sheath; it delicately insinuates itself out of it—I had almost said flows. It is as though it were expelled by a gentle pressure.

Let us return to the wings and elytra, which have made no apparent progress since their emergence from their sheaths. They are still mere stumps, with fine longitudinal seams; almost like little ropes'-ends. Their expansion, which will occupy more than three hours, is reserved for the end, when the insect is completely moulted and in its normal position.