The captive grub tries to escape its terrible neighbour. Turned over on its back according to its custom, it shuffles along eagerly, going round and round the glass arena. Soon, the Scolia’s attention is aroused and is evinced by continual little taps of the tips of its antennæ upon the table, which now represents the customary soil. The Hymenopteron falls upon her prey and attacks the monstrous meal by the hinder end. She climbs upon the Cetonia, using the abdominal extremity as a lever. The assaulted grub does nothing but scud all the faster on its back, without rolling itself into a defensive posture. The Scolia reaches the front part, after falls and accidents that vary greatly, according to the degree of tolerance of the grub, her temporary mount. With her mandibles, she nips a point on the upper surface of the thorax; she places herself across the grub, curves herself into an arch and tries to touch with the point of her belly the region where the sting is to be darted. The arch is a little too short to embrace almost the whole circuit of the corpulent prey, for which reason the efforts and attempts are made over and over again, at great length. The tip of the abdomen makes untold exertions, applies itself here, there and elsewhere and, as yet, stops nowhere. This tenacious searching in itself proves the importance which the paralyzer attaches to the spot at which its bistoury is to enter.

PLATE VIII

Meanwhile, the grub continues to move along on its [[147]]back. Suddenly, it buckles and, with a jerk of the head, flings the enemy to a distance. Undaunted by all her failures, the Hymenopteron stands up, brushes her wings and recommences the assault of the colossus, almost always by clambering on the grub by the rear extremity. At last, after any number of fruitless attempts, the Scolia succeeds in attaining the proper position. She lies across the grub; her mandibles hold a point of the thorax on the dorsal face tight-gripped; her body, curved into an arch, passes under the grub and reaches the neighbourhood of the neck with the tip of the belly. Placed in grave danger, the Cetonia twists, buckles, unbuckles, turns and writhes. The Scolia does not interfere. Holding her victim in a close embrace, she turns with it, allows herself to be dragged above, below, aside, at the mercy of the contortions. So fierce is her determination that I am now able to remove the glass bell and watch the details of the drama in the open.

Soon, notwithstanding the tumult, the tip of the Scolia’s belly feels that the suitable point is found. Then and not till then is the dart unsheathed. It is driven home. The thing is done. The grub, but now active and swollen, suddenly becomes inert and limp. It is paralyzed. Henceforth, all movement ceases, save in the antennæ and mouth-pieces, which will continue for a long time to declare a remnant of life.

The place of the wound has never varied in the series of struggles under the glass bell: it occupies the middle of the dividing line between the prothorax and the mesothorax, on the ventral surface. Let us observe that the Cerceris, who operates upon Weevils, which insects have a concentrated nervous chain like that of the Cetonia grub, inserts her sting at the same point. The similarity of the [[148]]nervous organization occasions a similarity of method. Let us observe also that the sting of the Scolia remains for some time in the wound and rummages with a pronounced persistency. To judge by the movements of the tip of the abdomen, one would say that the weapon is exploring and selecting. Free to turn about as it pleases within narrow limits, the sting’s point is probably searching for the little bundle of nerves which it must prick, or at least sprinkle with poison, in order to obtain a withering paralysis.

I will not end my report of the duel without relating a few more facts, of minor importance. The Two-banded Scolia is an ardent persecutor of the Cetonia. At one sitting, the same mother stabs three grubs, one after the other, before my eyes. She refuses the fourth, perhaps through fatigue, or because her poison-phial is exhausted. Her refusal is but temporary. The next day, she begins anew and paralyzes two worms; the following day again, but with a zeal that diminishes from day to day.

The other predatory insects that go on long hunting-expeditions embrace the prey which they have rendered lifeless, drag it, convey it, each in its own fashion, and, laden with their burden, long try to escape from the bell and to reach the burrow. Disheartened by vain attempts, they abandon it at last. The Scolia does not move her prey, which lies indefinitely on its back at the spot of sacrifice. After drawing her dagger from the wound, she leaves her victim alone and starts fluttering against the walls of the bell, without troubling about it further. Things must happen in the same way in the manure-heap, under normal conditions. The paralyzed morsel is not carried elsewhither, to a special cellar: where the struggle occurred, there it receives, on its spread [[149]]belly, the egg whence the consumer of the succulent dainty will presently emerge. This saves the expense of a house. It goes without saying that the Scolia does not lay under glass: the mother is too prudent to expose her egg to the dangers of the open air.

A second detail strikes me: the fierce persistency of the Scolia. I have seen the fight prolonged for a good quarter of an hour, with frequent alternations of successes and reverses, before the Hymenopteron achieved the requisite position and reached with the tip of her belly the point at which the sting must enter. During her assaults, which are resumed as soon as repelled, the aggressor repeatedly applies the extremity of her abdomen against the grub, but without unsheathing; for I should perceive this by the start of the animal injured by the prick. The Scolia, therefore, does not sting the Cetonia anywhere until the desired point offers beneath the weapon. The fact that no wounds are made elsewhere is not in any way due to the structure of the grub, which is soft and penetrable at all points, except the skull. The spot sought by the sting is no less well-protected than the others by the dermal wrapper.