[3] Claude Bernard (1813–1878), another distinguished French physiologist and perhaps the most famous representative of experimental science in the nineteenth century.—Translator’s Note. [↑]
[4] Annales des sciences naturelles, Series III., vol. v.—Author’s Note. [↑]
[5] For the Sacred Scarab, or Sacred Beetle, cf. Insect Life, by J. H. Fabre, translated by the author of Mademoiselle Mori: chaps. i. and ii.; and The Life and Love of the Insect, by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chaps, i. to iv.—Translator’s Note. [↑]
Chapter iv
THE YELLOW-WINGED SPHEX
Under their powerful armour, which no dart can penetrate, the insects of the Beetle tribe offer but a single vulnerable spot to the sting-bearing enemy. This defect in the breastplate is known to the murderess, who drives in her poisoned dagger there and at one blow strikes the three motor centres, for she selects her victims from the Weevil and Buprestis families, whose nervous system is centralized to the requisite degree. But what will happen when the prey is an insect clad not in mail but in a soft skin, which the Wasp can stab here or there indifferently, in any part of the body that chances to be exposed? In that case are the blows still delivered scientifically? Like the assassin who strikes at the heart to cut short the dangerous resistance of his victim, does the assailant follow the tactics of the Cerceres and wound the motor ganglia by preference? If that be so, then what happens when these ganglia are some distance apart and so independent [[59]]in their action that paralysis of one is not necessarily followed by paralysis of the others? These questions will be answered by the story of a Cricket-huntress, the Yellow-winged Sphex (Sphex flavipennis).
It is at the end of July that the Yellow-winged Sphex tears the cocoon that has protected her until then and flies out of her subterranean cradle. During the whole of August she is frequently seen flitting, in search of some drop of honey, around the spiked heads of the field eryngo, the commonest of the hardy plants that brave the heat of the dog-days in this month. But this careless life does not last long, for by the beginning of September the Sphex is at her arduous task as a sapper and huntress. She generally selects some small plateau, on the high banks by the side of the roads, wherein to establish her home, provided that she find two indispensable things there: a sandy soil, easy to dig; and sunshine. No other precaution is taken to protect the dwelling against the autumn rains or winter frosts. A horizontal site, unprotected, lashed by the rain and the winds, suits her perfectly, on condition, however, that it is exposed to the sun. And, when a heavy shower comes in the middle of her mining, it is pitiful next day to see the half-built galleries in ruins, choked [[60]]with sand and finally abandoned by their engineers.
The Sphex seldom practises her industry alone; the site selected is usually exploited by small bands of ten or twenty sappers or more. One must have spent days in contemplating one of these villages to form any idea of the restless activity, the spasmodic haste, the abrupt movements of those hard-working miners. The soil is rapidly attacked with the rakes of the forefeet: canis instar, as Linnæus says. No mischievous puppy displays more energy in digging up the ground. At the same time, each worker sings her glad ditty, which consists of a shrill and strident noise, constantly broken off and modulated by the vibrations of the wings and thorax. One would think that they were a troop of merry companions encouraging one another in their work with a cadenced rhythm. Meanwhile the sand flies, falling in a fine dust on their quivering wings; and the too bulky gravel, removed bit by bit, rolls far away from the workyard. If a piece seems too heavy to be moved, the insect gets up steam with a shrill note which reminds one of the woodman’s ‘Hoo!’ Under the redoubled efforts of tarsi and mandibles the cave soon takes shape; the insect is already able to dive into it bodily. We then see a lively alternation of forward [[61]]movements, to loosen new materials, and backward movements, to sweep the rubbish outside. In this constant hurrying to and fro the Sphex does not walk, she darts as though shot from a spring; she bounds with throbbing abdomen and quivering antennæ, her whole body, in short, animated with a musical vibration. The miner is now out of sight; but we still hear underground her untiring song, while at intervals we catch a glimpse of her hind-legs, pushing a torrent of sand backwards to the mouth of the burrow. From time to time the Sphex interrupts her subterranean labours, either to come and dust herself in the sun, to rid herself of the grains of sand which, slipping into her delicate joints, might hamper the liberty of her movements, or else to reconnoitre the neighbourhood. Despite these interruptions, which for that matter do not last long, the gallery is dug in the space of a few hours; and the Sphex comes to her threshold to chant her triumph and give the finishing polish to her work by removing some unevenness and carrying away a speck or two of earth whose drawbacks are perceptible to her discerning eye alone.
Of the numerous tribes of Sphex-wasps which I have visited, one in particular remains fixed in my memory because of its curious dwelling-place. [[62]]On the edge of a high-road were some small heaps of mud, taken from the ditches by the road-mender’s shovel. One of these heaps, long ago dried in the sun, formed a cone-shaped mound, resembling a large sugar-loaf twenty inches high. The site seemed to have attracted the Wasps, who had established themselves there in a more populous colony than I have ever since beheld. The cone of dry mud was riddled from top to bottom with burrows, which gave it the appearance of an enormous sponge. On every storey there was a feverish animation, a busy coming and going which reminded one of the scenes in some great yard when the work is urgent. Crickets were being dragged by the antennæ up the slopes of the conical city; victuals were being stored in the larders of the cells; dust was pouring from the galleries in process of excavation by the miners; grimy faces appeared at intervals at the mouths of the tunnels; there were constant exits and constant entrances; and now and again a Sphex, in her brief intervals of leisure, would climb to the top of the cone, perhaps to cast a look of satisfaction from this belvedere over the works in general. What a spectacle to tempt me, to make me long to carry the whole city and its inhabitants away with me! It was useless even to try: the mass was too [[63]]heavy. One cannot root up a village from its foundations to transplant it elsewhere.