Fabre's Book of Insects

by Jean-Henri Fabre

When I began to observe the ways of the Decticus I was anxious to watch the hatching, so at the end of August I gathered plenty of eggs, and placed them in a small glass jar with a layer of sand. Without suffering any apparent change they spent eight months there under cover, sheltered from the frosts, the showers, and the overpowering heat of the sun, which they would be obliged to endure out of doors.

When June came, the eggs in my jar showed no sign of being about to hatch. They were just as I had gathered them nine months before, neither wrinkled nor tarnished, but on the contrary wearing a most healthy look. Yet in June young Dectici are often to be met in the fields, and sometimes even those of larger growth. What was the reason of this delay, I wondered.

Then an idea came to me. The eggs of the Grasshopper are planted like seeds in the earth, where they are [[133]]exposed, without any protection, to snow and rain. Those in my jar had spent two-thirds of the year in a state of comparative dryness. Since they were sown like seeds, perhaps they needed, to make them hatch, the moisture that seeds require to make them sprout. I resolved to try.

I placed at the bottom of some glass tubes a pinch of backward eggs taken from my collection, and on the top I heaped lightly a layer of fine, damp sand. I closed the tubes with plugs of wet cotton, to keep the air in them constantly moist. Any one seeing my preparations would have supposed me to be a botanist experimenting with seeds.

My hopes were fulfilled. In the warmth and moisture the eggs soon showed signs of hatching. They began to swell, and the bursting of the shell was evidently close at hand. I spent a fortnight in keeping a tedious watch at every hour of the day, for I had to surprise the young Decticus actually leaving the egg, in order to solve a question that had long been in my mind.

The question was this. The Grasshopper is buried, as a rule, about an inch below the surface of the soil. Now the new-born Decticus, hopping awkwardly in the grass at the approach of summer, has, like the full-grown insect, a pair of very long tentacles, as slender as hairs; [[134]]while he carries behind him two extraordinary legs, two enormous hinged jumping-poles that would be very inconvenient for ordinary walking. I wished to find out how the feeble little creature set to work, with this cumbrous luggage, to make its way to the surface of the earth. By what means could it clear a passage through the rough soil? With its feathery antennæ, which an atom of sand can break, and its immense shanks, which are disjointed by the least effort, this mite is plainly incapable of freeing itself.

As I have already told you, the Cicada and the Praying Mantis, when issuing, the one from his twig, and the other from his nest, wear a protective covering like an overall. It seemed to me that the little Grasshopper, too, must come out through the sand in a simpler, more compact form than he wears when he hops about the lawn on the day after his birth.

Nor was I mistaken. The Decticus, like the others, wears an overall for the occasion. The tiny, flesh-white creature is cased in a scabbard which keeps the six legs flattened against the body, stretching backwards, inert. In order to slip more easily through the soil his shanks are tied up beside him; while the antennæ, those other inconvenient appendages, are pressed motionless against the parcel.

The head is very much bent against the chest. With [[135]]the big black specks that are going to be its eyes, and its inexpressive, rather swollen mask, it suggests a diver’s helmet. The neck opens wide at the back, and, with a slow throbbing, by turns swells and sinks. It is by means of this throbbing protrusion through the opening at the back of the head that the new-born insect moves. When the lump is flat, the head pushes back the damp sand a little way and slips into it by digging a tiny pit. Then the swelling is blown out and becomes a knob which sticks firmly in the hole. This supplies the resistance necessary for the grub to draw up its back and push. Thus a step forward is made. Each thrust of the motor-blister helps the little Decticus upon the upward path.

It is pitiful to see this tender creature, still almost colourless, knocking with its swollen neck and ramming the rough soil. With flesh that is not yet hardened it is painfully fighting stone; and fighting it so successfully that in the space of a morning it makes a gallery, either straight or winding, an inch long and as wide as an average straw. In this way the harassed insect reaches the surface.