[Illustration: Fig. 191.--Pupa of Sphinx ligustri.] It is to the genus _Acherontia_ that a well-known moth belongs. We refer to the Death's-head Moth (_Acherontia atropos_). It is the largest species of hawk-moth. This insect presents, roughly marked out in light yellow, on the black ground of its thorax, a human skull. This funeral symbol, joined to the plaintive cry which this moth emits when frightened, has sometimes inspired terror into the whole population of a country. The appearance of this moth in certain countries having coincided with the invasion of an epidemic disease, some thought they saw in this doleful sylph of the night the messenger of death. The _Acherontia atropos_ plays a great part in the superstitions which are believed in by the country folk in England. One hears it said in country places that this ominous inhabitant of the air is in league with the witches, and that it goes and murmurs into their ears with its sad and plaintive voice the name of the person whom death is soon to carry off. In spite of its ominous livery, the _Atropos_ does not come from Hades; it is no envoy of death, bringing sadness and mourning. It does not bring us news of another world; it tells us, on the contrary, that Nature can people every hour; that it was her will to console them for their sadness, to grant to the twilight and to the night the same winged wanderers which are at once the delight and ornament of the hours of light and of day. [Illustration: Fig. 192.--The Convolvulus Sphinx (_Sphinx convolvuli_).] This is the mission of science, to dissipate the thousands of prejudices and dangerous superstitions which mislead ignorant people. [Illustration: Fig. 193.--Death's-head Hawk-Moth (_Acherontia atropos_).] This moth has the front wings of a blackish brown colour, having lighter irregular bands varied with brown and grey, above and below. On the middle of the front wing there is a well-defined white dot. The hind wings have two black bands, the upper narrower than the lower one; the rest of the wing is a fine yellow. The abdomen has likewise from five to six yellow and as many black bands; in the middle is a long blackish longitudinal band. This moth is not very rare, and may be found in autumn. Its flight is heavy, and, as we have said, the insect never flies till after sunset. If caught, or when teased, it utters a cry which is very audible. The death's-head hawk-moth would be a very inoffensive being if it did not make its way into bee-hives, in order to steal the honey, of which it is excessively fond. It is to no purpose that the bees dart their stings at the intruder, they only blunt them against its thick skin, and soon, terrified at its presence, disperse on all sides. [Illustration: Fig. 194.--Larva of the Death's-head Hawk-Moth (_Acherontia atropos_).]