The Insect World: Being a Popular Account of the Orders of Insects

• ** Armales des Sciences Naturelles," 1857, 46 serie, tome vii., p. 300.

COLEOPTERA. 5O9

manner as the companions of Ulysses watched the sheep of Polyphemus, so as to escape out of the cave in which they were retained as prisoners. A few days later, and this second larva contracts, and detaches from its body a transparent skin, which discloses a mass, at first soft, which very soon hardens, and becomes of a bright tawny ^ colour^ it is called \hQ pseiido-fiymph (Fig. 547). It goes through the winter in this state. In the spring comes forth a third larva (Fig. 548), resembling the second. This one does not eat, and moults after a time. It very soon changes into an ordinary pupa (Fig. 549), of a yellowish-white, from which comes forth the adult Sitaris, which lives only a few days, to ensure the propagation of its species, as is " observed in the case of the Ephemera. The larvae of the Sitaris had ^for a long time been remarked clinging on to the hairs of the

fig- 550 • — Lampyris noctiluca (male and female).

Anthophorce, but they were always taken for Acari, and they had been described as such. The LampyridcE have the elytra weak and soft, like the insects of the preceding tribe. In their perfect state they frequent flowers. i^The larvae are carnivorous, attacking other insects or worms. It is to ^' this group that the Lampyris noctiluca, or glow-worm, which one sees *^'! shining during summer nights on grass and bushes, belongs. It has the power of making this natural torch shine or disappear at will.

The luminous properties with which these insects are endowed fifhave for their object to reveal their presence to the opposite sex, for li the females alone possess these properties. In the same way as sounds or odours exhaling from some insects attract the one towards the other sex, so with the Lampyris a phosphorescent light shows the females to the males. The seat of the phosphorescent substance varies according to the species. It exists generally under the three last rings of the abdomen, and the light is produced by the slow-combustion of a peculiar secretion. It has been stated that it is evolved quickly when the animal contracts its muscles, either

spontaneously or under the influence of artificial excitement. Somf chemical experiments have been made to ascertain the nature or tht composition of the humour which produces this strange effect; bui up to this moment, they have only enabled us to discover that th( luminous action is more powerful in oxygen, and ceases in gasej incapable of supporting combustion. In the most common species the Lampyris nodiliica^ or glow-worm, the phosphorescence is of i greenish tint: it assumes at certain moments the brightness of white hot coal. The females have no wings, while the males have them, and possess very well-developed elytra. The females resemble the larvae much, only they have the head more conspicuous, and th( thorax buckler-shaped, like the male. The larvae feed on smal molluscs, hiding in the snails' shells, after having devoured the inhabitant. They also possess the phosphorescent property in a lesi degree than the adult females. The female pupa resembles tlu larva, the pupa of the male, on the contrary, has the wings foldec back under a thin skin. The perfect insect appears towards th( autumn. The Glow-worm {Lampyris jwdiluca^ Fig. 550) is of a brownisl yellow. It is common in England. In a kindred species, th( Luciola Italica, the two sexes are winged, of a tawny-brown, anc equally phosphorescent. They are met with in great numbers ir Italy, and the lawns are covered with them. Other insects of thi: family are without the faculty of emitting light; as, for example, th( genus Lycus, of brilliant colours, which are met with in Africa anc India. One of the finest is the Lycus latissifmis.

Drilus is another genus, comprising insects of very singula: habits. The type is the Drilus flavescens. The male — a quarter 0 an inch long, black and hairy, with elytra of a testaceous yellow, am with pectinated antennae — for a long time was alone known. Th( female — from ten to fifteen times as large, without wings and elytra of a yellowish brown — was not discovered till much later, having apparently nothing in common with the male in shape or colour The metamorphoses of these curious insects are now perfectly under stood. Mielzinsky, a Polish naturalist established at Gene^-"found the Drilus in the larva state in the shell of the ILelix neniorii These larvae devour the snail whose dwelling they occupy, as do tin larvae of the Lampyris. Mielzinsky saw them emerge, but obtainecl only females, which differed scarcely at all from the larvae from whicl they proceeded. He made a separate genus of them, under th( ' denomination of Cochleoctonus^ and called the species Vorax. Latt

■I

COLEOFTERA.

Desmarest resumed these observations. He provided himself, at the Veterinary College of Alfort, with a number of shells of the Helix filled with the same larvae. He saw come out of them, not only Cochleoctoni, but also Drili^ and he watched their coupling. It was then proved, by this unanswerable argument, that these two insects,5ir so unlike each other, belong to the same species.

The larva of the Drilus fiavescens fixes itself upon the shell of the snail by a sort of sucker, like a leech. Little by little it slips in between the mollusc and its house, and devours it entirely. To

Fig- 553.— Jumping organ of the Elater, seen bidewaya,

Fig. 551. — Jumping organ Fig. 553. — Larva of the Elatefi of the Elater.

change into a pupa, it shuts up the entrance to the shell with its old skin; and when arrived at the perfect state, quits the shell which served it as a temporary dwelling. The females of the Drilus fiavescens take refuge under stones and dry leaves, or crawl slowly along the ground; whilst the males, which fly with great ease, are on the plants and brushwood. These insects are not rare in the environs of Paris. M. H. Lucas has observed, in Algeria, near to Oran, another curious species, the Drilus Mauritaniciis. The larva of this insect lives at the expense of the animal of the Cyclostoma Volzia?tum, which closes the entrance to its shell with a covering of some calcareous substance. It fixes itself on the edge of the shell, with the aid of its sucker, and directs its strong mandibles to the side on which the snail is obliged to raise the covering, either to breathe the air or to walk. In this position it has the patience to wait for.

many days at the door. The snail puts off for as long a time as ^e is able the fatal moment. But whenj overcome by hunger or nearly stifled in his prison, he decides at last to open the door, the Drilus profits immediately by this opportunity, and cuts the muscle which keeps back the foot of the snail. The breach being made, nothing more opposes itself to the entrance of the enemy. He slips in, and sets to work to eat at his leisure the unfortunate inoffensive mollusc, which affords him board and lodging. The Ptilodadylides^ the Eticinelides, and the Cebrionides belong to the same family. The first is exotic. The ElateridcB are rather large insects, often of hard texture, having the presternum prolonged into a point (Figs. 551 and 552), and the antennae indented saw-wise. They have the power of jumping when placed on their backs, and of alighting again on their legs. Hence their name of Elater (derived from the same root as the word elastic). They produce, in leaping, one sharp rap, and often knock many raps when they are prevented from projecting themselves. This is the mechanism which permits the skip-jack to execute these movements. It bends itself upwards by resting on the ground by its head and the extremity of the abdomen, and then it unbends itself suddenly, like a spring. The point at the end of the thorax penetrates into a hollow of the next ring; the back then strikes with force against the plane on which it rests, and the animal is projected into the air. It repeats this manoeuvre till it finds itself on its belly, for its legs are too short to allow of its turning over. Its structure supplies it with the means and the strength of rebounding as many times as it falls on its back, and it can thus raise itself more than twelve times the length of its body.

The larvae of the genus Elateridce (Fig. 553) are cylindrical, with a scaly skin and very short legs. They live in rotten wood or in the roots of plants. According to M. Goureau, they pass five years in this state. The larvae of the genus Agriotes occasion considerable damage to wheat-fields. They have much resemblance to the meal-worm, or larva of the Tenebrio. The Tetralobides are the largest of the Elateridce, attaining to a length of two inches; and are inhabitants of Africa and Austraha. In America are found phosphorescent Elateridce, These are the Fyrop/iori, which the Spaniards of South America call by the name of Cucuyos. They have, at the base of their thorax, two small, smooth, and brilliant spots, which sparkle during the night; the rings of the abdomen also emit a light. They give light sufficient to

enable one to read at a little distance from them. The Pyrophorus noctihicus (Fig. 554) is very common in Havannah, in Brazil, in Guiana, in Mexico, &c., and may be seen at night in great numbers, amongst the foliage of trees. At the time of the Spanish conquest, a battaHon, just disembarked, did not dare to engage with the natives, because it took the Cucuyos which were shining on the neighbouring trees for the matches of the arquebuses ready to fire. " In these countries," says M. Michelet, " one travels much by night, to escape the heat. But one would not dare to plunge into the peopled shades of the deep forests if these insects did not reassure the traveller. He sees them shining afar off, dancing, twisting about; he sees them near at hand on the bushes by his side; he takes them with him; he fixes them on his boots, so that they may show him his road and put to flight the serpents; but when the sun rises, gratefully and carefully he places them on a shrub, and restores them to their amorous occupations. It is a beautiful Indian proverb that says, ' Carry away the fire-fly, but restore it from whence thou, hast taken it.' " * Creole women make use of the Cucuyos to increase the splendour of their toilettes. Strange jewels! which must be fed, which must be bathed twice a day, and must be incessantly taken care of, to prevent them from dying. The Indians catch these insects by balancing hot coals in the air, at the end of a stick, to attract them, which proves that the light which these insects diffuse is to attract. Once in the hands of the women, the Cucuyos are shut up in little cages of very fine wire, and fed on fragments of sugar-cane. When the Mexican ladies wish to adorn themselves with these hving diamonds, they place them in little bags of light tulle, which they arrange with taste on their skirts. There is another way of mounting the Cucuyos. They pass a pin, without hurting them, under the thorax, and stick this pin in their hair. The refinem.ent of elegance consists in combining with the Cucuyos, humming-birds and real diamonds, which produce a dazzling head-dress. Sometimes, imprisoning these animated flames in gauze, the graceful Mexican women twist them into ardent necklaces, or else roll them round their waists, like a fiery girdle. They go to the ball under a diadem of living topazes, of animated emeralds, and this diadem blazes or pales according as the insect is fresh or fatigued. When they return home, after the soiree, they make them take a bath, which refreshes them, and put them back again into the cage, which sheds during the whole night a soft light in the chamber. In 1766, a Cucuyo, brought alive from