The numerical predominance in the Tachytes' cells belongs to the Praying Mantis; and the Grey Mantis occupies second place. The Empusa, who is comparatively rare on the brushwood in the neighbourhood, is also rare in the store-houses of the Wasp; nevertheless her presence is repeated often enough to show that the huntress appreciates the value of this prey when she comes across it. The three sorts of game are in the larval state, with rudimentary wings. Their dimensions, which vary a good deal, fluctuate between two-fifths and four-fifths of an inch in length.
The Praying Mantis is a bright green; she boasts an elongated prothorax and an alert gait. The other Mantis is ash-grey. Her prothorax is short and her movements heavy. The coloration therefore is no guide to the huntress, any more than the gait. The green and the grey, the swift and the slow are unable to baffle her perspicacity. To her, despite the great difference in appearance, the two victims are Mantes. And she is right.
But what are we to say of the Empusa? The insect world, at all events in our parts, contains no more fantastic creature. The children here, who are remarkable for finding names which really depict the animal, call the larva "the Devilkin." It is indeed a spectre, a diabolical phantom worthy of the pencil of a Callot. (Jacques Callot (1592-1635), the French engraver and painter, famous for the grotesque nature of his subjects.--Translator's Note.) There is nothing to beat it in the extravagant medley of figures in his "Temptation of Saint Anthony." Its flat abdomen, scalloped at the edges, rises into a twisted crook; its peaked head carries on the top two large, divergent, tusk-shaped horns; its sharp, pointed face, which can turn and look to either side, would fit the wily purpose of some Mephistopheles; its long legs have cleaver-like appendages at the joints, similar to the arm-pieces which the knights of old used to bear upon their elbows. Perched high upon the shanks of its four hind-legs, with its abdomen curled, its thorax raised erect, its front-legs, the traps and implements of warfare, folded against its chest, it sways limply from side to side, on the tip of the bough.
Any one seeing it for the first time in its grotesque pose will give a start of surprise. The Tachytes knows no such alarm. If she catches sight of it, she seizes it by the neck and stabs it. It will be a treat for her children. How does she manage to recognize in this spectre the near relation of the Praying Mantis? When frequent hunting-expeditions have familiarized her with the last-named and suddenly, in the midst of the chase, she encounters the Devilkin, how does she become aware that this strange find makes yet another excellent addition to her larder? This question, I fear, will never receive an adequate reply. Other huntresses have already set us the problem; others will set it to us again. I shall return to it, not to solve it, but to show even more plainly how obscure and profound it is. But we will first complete the story of the Mantis-killing Tachytes.
The colony which forms the subject of my investigations is established in a mound of fine sand which I myself cut into, a couple of years ago, in order to unearth a few Bembex larvae. The entrances to the Tachytes' dwelling open upon the little upright bank of the section. At the beginning of July the work is in full swing. It must have been going on already for a week or two, for I find very forward larvae, as well as recent cocoons. There are here, digging into the sand or returning from expeditions with their booty, some hundred females, whose burrows, all very close to one another, cover an area of barely a square yard. This hamlet, small in extent, but nevertheless densely populated, shows us the Mantis-slayer under a moral aspect which is not shared by the Locust slayer, Panzer's Tachytes, who resembles her so closely in costume. Though engaged in individual tasks, the first seeks the society of her kind, as do certain of the Sphex-wasps, while the second establishes herself in solitude, after the fashion of the Ammophila. Neither the personal form nor the nature of the occupation determines sociability.
Crouching voluptuously in the sun, on the sand at the foot of the bank, the males lie waiting for the females, to plague them as they pass. They are ardent lovers, but cut a poor figure. Their linear dimensions are barely half those of the other sex, which implies a volume only one-eighth as great. At a short distance they appear to wear on their heads a sort of gaudy turban. At close quarters this headgear is seen to consist of the eyes, which are very large and a bright lemon-yellow and which almost entirely surround the head.
At ten o'clock in the morning, when the heat begins to grow intolerable to the observer, there is a continual coming and going between the burrows and the tufts of grass, everlasting, thyme and wormwood, which constitute the Tachytes' hunting-grounds within a moderate radius. The journey is so short that the Wasp brings her game home on the wing, usually in a single flight.
She holds it by the fore-part, a very judicious precaution, which is favourable to rapid stowage in the warehouse, for then the Mantis' legs stretch backwards, along the axis of the body, instead of folding and projecting sideways, when their resistance would be difficult to overcome in a narrow gallery. The lanky prey dangles beneath the huntress, all limp, lifeless and paralysed. The Tachytes, still flying, alights on the threshold of the home and immediately, contrary to the custom of Panzer's Tachytes, enters with her prey trailing behind her. It is not unusual for a male to come upon the scene at the moment of the mother's arrival. He is promptly snubbed. This is the time for work, not for amusement. The rebuffed male resumes his post as a watcher in the sun; and the housewife stows her provisions.
