The extermination is so complete that, to obtain pupæ, I have to resort to rearing them in private, guarding the larvæ against the invasion of the Saprini. The earthenware pans in the open air, though thoroughly searched, never yield me any, however numerous the maggots were at the outset. During my earlier experiments, when as yet I had no suspicion of the massacre, I could not get over my surprise when, after noting an abundance of vermin under this or that piece of carrion a few days before, I no longer found anything, even in the sand. I should have concluded that the occupants had migrated in a body, had it been permissible to imagine a maggot making a long journey through a waterless world.
The Saprini, those lovers of fat sausages are entrusted with the task of thinning out the Grey Fly, of whose twenty thousand offspring only a few will survive, just enough to maintain the race within proper limits. They flock about the dead Mole or Adder; but, kept at a distance by the too liquid sanies and, for that matter, able to live on a few frugal mouthfuls, they wait until the maggots’ work is finished. Then, the liquefaction of the corpse completed, they slaughter [[40]]the liquidators. To purge the soil swiftly of life’s offal, the scavenging maggot multiplies its legions; then, having itself become a peril by reason of its numbers, it disappears, exterminated, when its cleansing task is done.
In my district, I obtain nine species of Saprini, some found under carrion, others under dung. I give their names in a footnote.[6] The first four species hasten to my earthenware pans, but the most numerous and most assiduous, those on whom the bulk of the work falls, are S. subnitidus and S. detersus. They arrive as early as April, at the same time as the Luciliæ, whose offspring they ravage with the same zeal as that of the Grey Fly. Both of them abound in my charnel-pits until the torrid sun of the dog-days puts an end to the invasion of the Flies by drying up the exposed carrion too quickly. They reappear in September, with the first cool breezes of autumn.
Flesh or fish, fur, feather or reptile, everything suits them because it also attracts the [[41]]maggot, their favourite meat. While waiting for the vermin to grow, they take a few sips of the sanies; but these are scarcely more than an appetizer in preparation for the great feast, when the wriggling grubs are fattened to a turn.
Seeing them so active, one at first pictures them as occupied with family-cares. So I believed; and I was wrong. Under the carrion in my necrotic laboratory, there is never an egg belonging to them, never a larva. The family must be established elsewhere, in the dung-hills and dust-heaps apparently. I have, in fact, found their nymphs, which are easily recognized, in March, on the floor of a poultry-run saturated with the droppings of the fowls. The adults visit my retting-pans to feast upon the maggot. When their mission is accomplished, in the late autumn, they seem to return to the filth under whose shelter the generation is prepared which, as soon as winter is over, hastens to the dead bodies of animals to moderate the excesses of the Sarcophagæ[7] and the Luciliæ.
The labours of the Fly do not satisfy the requirements of hygiene. When the soil [[42]]has drunk the cadaveric extract elaborated by the grubs, a great deal remains that cannot be liquefied or dried up by the heat. Other workers are needed, who treat the mummified carcase anew, nibbling at the shrivelled muscles and tendons until the relics are reduced to a heap of bones as clean as ivory.
The Dermestes are charged with this long labour of gnawing. Two species come to my earthenware pans at the same time as the Saprini: D. undulatus, Brahm., and D. Frischii, Kugel. The first, striped with fine, snow-white, wavy lines on a black ground, has a red corselet speckled with brown spots; the second, the larger of the two, is dull black all over, with the sides of the corselet powdered ashen grey. Both wear white flannel underneath, which forms a violent contrast with the rest of the costume and seems inconsistent with the insect’s calling.
The Necrophorus,[8] the burier of the dead, has already shown us this propensity for soft stuffs and the clash of discordant colours. He covers his breast with a waistcoat of nankeen [[43]]flannel, decorates his wing-cases with red stripes and sports an orange club at the tip of his antennæ. The Wavy Dermestes, wearing a leopard-skin cape and a jerkin striped with ermine, could almost, humble though he be, rival the elegance of this mighty undertaker.
Both of them numerous, the two Dermestes come to my earthenware receptacles with a common aim; to dissect the dead body to the bone and to feed on what the maggots have left. If the work of these is not completed, if the lower surface of the corpse is still oozing, they wait, gathered on the edges of the pan or clinging in long rows to the cords by which it is slung. In their tumultuous impatience, falls are frequent, which throw the clumsy insect on its back and for a moment reveal the white flannel of the belly. The thoughtless Beetle soon recovers his feet, runs away and once more climbs the strings. In the kindly sunshine, frequent pairings occur, which is another way of killing time. There are no fights for the best places and the best morsels. The banquet is plentiful; there is room for all.
At last the victuals are in the requisite [[44]]condition; the maggots have disappeared, carried off by the Saprini; these last are themselves becoming scarce and are repairing elsewhither in search of another hoard of vermin. The Dermestes take possession of the corpse and remain indefinitely, even during the cruel dog-days, when the excessive heat and drought have put all else to flight. Under cover of the dried-up carcase, in the shadow of the Mole’s fur, which makes an impenetrable screen, they nibble and gnaw and clip as long as a scrap of edible matter remains on the bones.