In the struggle, the Scolia, curved archwise, is sometimes caught in the vice of the Cetonia, which forcibly contracts and buckles itself. Heedless of the rough embrace, the Hymenopteron does not let go with either her teeth or her ventral tip. Then follows a confused scuffle between the two locked insects, of which first one and next the other is on the top. When the grub succeeds in ridding itself of its enemy, it unrolls itself afresh, stretches itself at full length and proceeds to paddle along on its back with all possible speed. Its defensive artifices amount to no more than this. At an earlier [[150]]period, when I had not yet seen for myself and was obliged to take probability for my guide, I was willing to grant it the trick of the hedgehog, who rolls himself into a ball and defies the dog. I thought that, doubled up, with a force which my fingers had some difficulty in overcoming, it would in like manner defy the Scolia, who was powerless to unroll it and disdainful of any point but that of her choice. I wished the grub to possess and I believed that it did possess this very simple and efficacious means of defence. But I had too great confidence in its ingenuity. Instead of copying the hedgehog and remaining contracted, it flees with its belly in the air; foolishly, it adopts the very posture which allows the Scolia to make the assault and to reach the point at which the fatal blow is struck.
Let us pass on to others. I have just captured an Interrupted Scolia (Colpa Interrupta, Latr.), exploring the sands, no doubt in quest of game. It is important to make use of her as soon as may be, before her ardour has been cooled by the tedium of captivity. I know her prey, the grub of Anoxia Australis; I know, from my old habits of digging, the spots beloved by the worm: the sand-dunes heaped by the wind at the foot of the rosemary-shrubs on the slopes of the neighbouring hills. It will be hard work finding it, for nothing is rarer than a common thing, when it is needed in a hurry. I call in the aid of my father, an old man of ninety, but still straight as a wand. Shouldering a shovel and a three-pronged luchet, we set out under a sun in which you could cook an egg. Exerting our feeble powers in turns, we cut a trench in the sand where I hope to find the Anoxia. My hopes are not disappointed. In the sweat of my brow—never was truer word spoken—after shifting and sifting [[151]]through my fingers at least two cubic yards of sandy soil, I am the fortunate possessor of two grubs. Had I not wanted them, I should have dug them up by the handful! However, my lean and costly harvest is sufficient for the moment. To-morrow, I shall send stronger arms to continue the digging.
And now let us repay ourselves for our trouble by witnessing the drama under glass. Heavy and clumsy in her ways, the Scolia moves slowly round the arena. At the sight of the game, her attention wakes up. The fight is heralded by the same preparations as those displayed by the Two-banded Scolia: the Hymenopteron polishes her wings and taps the table with the tips of her antennæ. And now, up, lads, and at ’em! The attack begins. Unfit to move over a flat surface, because of its short, weak legs; lacking, moreover, the Cetonia’s eccentric means of locomotion on its back, the big-bellied worm does not dream of running away: it rolls itself up. The Scolia, with her powerful nippers, grabs its skin, now at once place, now at another. Buckled into an arch whose two ends almost meet, she strives to thrust the tip of her belly into the narrow opening of the volute formed by the grub. The fight is conducted quite calmly, without hard blows and with varying fortunes. It represents the obstinate attempt of a live split ring trying to slip one of its ends into another live split ring, which displays an equal obstinacy in remaining closed. The Scolia holds the game in subjection with her legs and mandibles; she makes her attempt first on one side and then on the other, without succeeding in unrolling the torus, which becomes the more contracted the more it feels itself in danger. The actual circumstances make the operation difficult: the prey slips and rolls over the table, when the insect [[152]]goes for it too briskly; points of support are wanting and the sting cannot reach the desired spot; for over an hour, one vain attempt follows upon the other, divided by spells of rest, during which the two adversaries look like two narrow rings wound one inside the other.
What ought the sturdy Cetonia grub to do in order to defy the Two-banded Scolia, who is nothing like so strong as her victim? Imitate the Anoxia, of course, and remain rolled up like a hedgehog until the enemy retreats. It tries to flee, unrolls itself and thus causes its own undoing. The other does not budge from its defensive posture and resists successfully. Is this due to acquired prudence? No, but to the impossibility of acting otherwise on the polished surface of a table. Heavy, obese, weak-legged, bent into a hook after the manner of the common white maggot, the Anoxia grub is unable to shift its position on a smooth surface; it flounders painfully, lying on its side. What it wants is the shifting soil wherein, using its mandibles as a spade, it digs and buries itself.
Let us try if sand will shorten the battle, of which the end does not yet seem in sight after an hour’s waiting. I lightly sprinkle the arena. The attack is resumed more fiercely than ever. The grub, feeling the sand, its natural dwelling-place, now also tries to slip away, the reckless one! What did I tell you? Its torus does not represent acquired prudence, but the necessity of the moment. The harsh experience of past misfortunes has not yet taught it the precious advantage which it would derive from its volute kept closed as long as danger lasts. Besides, not all are equally cautious on the firm support of my table. The biggest even seem ignorant of what they understood so well in their youth: the art of self-defence by rolling one’s self in a ball. [[153]]
I take up my story again with a fine-sized quarry, less liable to slip under the Scolia’s pushes. The grub, when assailed, does not curl up, does not contract into a ring, like its predecessor, which was younger and but half its size. It tosses about clumsily, lying on its side, half-opened. Its only attempt at defence is to wriggle; it opens, closes and reopens its big mandibular hooks. The Scolia grabs it at random, winds her rough, hairy legs around it and, for nearly fifteen minutes, strives her hardest atop of the rich dainty.
At last, after a series of not very riotous affrays, the favourable position is gained, the propitious moment arrives and the sting is planted in the grub’s thorax, at a central spot, under the neck and level with the fore-legs. The effect is instantaneous: total inertia, save in the appendages of the head, the antennæ and mouth-pieces. I find the same results, the same prick at a precise, invariable spot, among my different operators, captured from time to time with a successful stroke of the net.
Let us say, in conclusion, that the attack delivered by the Interrupted Scolia is much less fiery than that of her two-banded sister. This rough, sand-digging Hymenopteron has a clumsy gait and stiff, almost automatic movements. She does not easily repeat her dagger-thrust. Most of those with whom I experimented refused a second victim on the day after their exploits and on the following day. Half-asleep, they grew excited only when stimulated through my teasing them with a straw. Nor does the Two-banded Scolia, that more agile, more enthusiastic huntress, invariably unsheath when invited so to do. All those Nimrods are liable to moments of inaction which the presence of a new prey will not succeed in disturbing. [[154]]
The Scoliæ have taught me no more than I have said, for lack of subjects belonging to other species. No matter: the results obtained constitute, to my mind, no small triumph. After seeing the Scoliæ at work, I said to myself, guided merely by the anatomical structure of the victims, that the grubs of Cetonia, of Anoxia, of Oryctes must be paralyzed with a single prick of the sting; I even specified the point at which the dagger had to strike, a central point in the immediate neighbourhood of the fore-legs. Of the three kinds of sacrificers, two allowed me to be present at their surgical operation, which the third, I am certain, will not contradict. In both cases, a single blow of the lancet; in both cases, an inoculation with the poison at the place settled in advance. No calculator in an observatory could show greater accuracy in foretelling the position of his planet. An idea may be considered proved when it attains this mathematical anticipation of the future, this positive knowledge of the unknown. When will the extollers of chance achieve a like success? Order calls for order; and chance has no rule. [[155]]