1. THE CIGALE LAYING HER EGGS.
2. THE GREEN GRASSHOPPER, THE FALSE CIGALE OF THE NORTH,
DEVOURING THE TRUE CIGALE, A DWELLER IN THE SOUTH.
This was instructive. The attack was delivered high up above my head, in the early morning, while the Cigale was resting; and the struggles of the unfortunate creature as it was dissected alive had resulted in the fall of assailant and assailed together. Since then I have often been the witness of similar assassinations.
I have even seen the grasshopper, full of audacity, launch itself in pursuit of the Cigale, who fled in terror. So the sparrow-hawk pursues the skylark in the open sky. But the bird of prey is less ferocious than the insect; it pursues a creature smaller than itself. The locust, on the contrary, assails a colossus, far larger and far more vigorous than its enemy; yet the result is a foregone conclusion, in spite of this disproportion. With its powerful mandibles, like pincers of steel, the grasshopper rarely fails to eviscerate its captive, which, being weaponless, can only shriek and struggle.
The Cigale is an easy prey during its hours of somnolence. Every Cigale encountered by the ferocious grasshopper on its nocturnal round must miserably perish. Thus are explained those sudden squeaks of anguish which are sometimes heard in the boughs during the hours of the night and early morning, although the cymbals have long been silent. The sea-green bandit has fallen upon some slumbering Cigale. When I wished to rear some green grasshoppers I had not far to seek for the diet of my pensioners; I fed them on Cigales, of which enormous numbers were consumed in my breeding-cages. It is therefore an established fact that the green grasshopper, the false Cigale of the North, will eagerly devour the true Cigale, the inhabitant of the Midi.
But it is neither the sparrow nor the green grasshopper that has forced the Cigale to produce such a vast number of offspring. The real danger is elsewhere, as we shall see. The risk is enormous at the moment of hatching and also when the egg is laid.
Two or three weeks after its escape from the earth—that is, about the middle of July—the Cigale begins to lay. In order to observe the process without trusting too much to chance, I took certain precautions which would, I felt sure, prove successful. The dry Asphodelus is the support preferred by the insect, as previous observations had assured me. It was also the plant which best lent itself to my experiments, on account of its long, smooth stems. Now, during the first years of my residence in the South I replaced the thistles in my paddock by other native plants of a less stubborn and prickly species. Among the new occupants was the asphodel. This was precisely what I needed for my experiments. I left the dry stems of the preceding year in place, and when the breeding season arrived I inspected them daily.
I had not long to wait. As early as July 15th I found as many Cigales as I could wish on the stems of the asphodel, all in process of laying. The gravid female is always solitary. Each mother has her twig to herself, and is in no danger of being disturbed during the delicate operation of laying. When the first occupant has departed another may take her place, and so on indefinitely. There is abundance of room for all; but each prefers to be alone as her turn arrives. There is, however, no unpleasantness of any kind; everything passes most peacefully. If a female Cigale finds a place which has been already taken she flies away and seeks another twig directly she discovers her mistake.
The gravid female always retains an upright position at this time, as indeed she does at other times. She is so absorbed in her task that she may readily be watched, even through a magnifying glass. The ovipositor, which is about four-tenths of an inch in length, is plunged obliquely and up to the hilt into the twig. So perfect is the tool that the operation is by no means troublesome. We see the Cigale tremble slightly, dilating and contracting the extremity of the abdomen in frequent palpitations. This is all that can be seen. The boring instrument, consisting of a double saw, alternately rises and sinks in the rind of the twig with a gentle, almost imperceptible movement. Nothing in particular occurs during the process of laying the eggs. The insect is motionless, and hardly ten minutes elapse between the first cut of the ovipositor and the filling of the egg-chamber with eggs.
The ovipositor is then withdrawn with methodical deliberation, in order that it may not be strained or bent. The egg-chamber closes of its own accord as the woody fibres which have been displaced return to their position, and the Cigale climbs a little higher, moving upwards in a straight line, by about the length of its ovipositor. It then makes another puncture and a fresh chamber for another ten or twelve eggs. In this way it scales the twig from bottom to top.