*'Note sur les Termites de la Rochelle." Annales des Sciences Naturelles, 3e serie, tome xx., p. 18. 1853. f " Memoire sur les Termites observes a Rochefort." Saintes, 1843.

uninhabited, and which they had completely undermined. In 1804, Latreille relates, as a " hearsay," that the termites had for some years made the inhabitants of Rochefort uneasy; but in 1829 the same author tells a very different tale. He speaks with dismay of the ravages committed by this insect in the workshops belonging to the Royal Navy. The importation of the termes into France is then of recent date. A note which was sent to M. de Quatrefages by M. Beltrémieux, fixes with still greater accuracy the date of the importation of the termites; it must have taken place about 1780, a period at which the brothers Poupet, rich shipowners, caused bales of goods to come from St. Domingo to Rochefort, to La Rochelle, and to other places in that neighbourhood which possess storehouses. The ravages which the termites have committed in the towns of La Saintonge are really frightful. Like Valencia, in New Granada, these towns will find themselves one of these days suspended over catacombs. At Tournay-Charente, the floor of a dining-room fell in, and the Amphytrion and his guests tumbled together in the cellar. There may be seen in the galleries of the Museum of Natural History of Paris the wooden columns which supported this room, and which were preserved by Audouin, who had been sent on a mission to report on the damages done. Audouin also selected, as an object of curiosity, a lady's bridal veil, which had been entirely riddled with holes by the termites.

At La Rochelle these insects took possession of the Prefect's house (built by the brothers Poupet), and of the Arsenal. There they invaded offices, apartments, court, and garden. They could not drive in a stake, or leave a plank in the garden, but it was attacked the next day. One fine morning the archives of the department were found destroyed, without there being the smallest trace of the damage to be seen on the exterior. The termites had mined through the wood-work, pierced the card-board, eaten up the parchments and the papers of the administration, but had always scrupulously respected the upper leaf and edges of all the leaves. It was by mere chance that a clerk, less superficial than his colleagues, one fine day raised one of the leaves which hid this detritus, and thus discovered the destruction of the archives. All the papers of the Prefecture are now shut up in boxes of zinc.

These termites do not venture, any more than their congeners, into the light of day. These terrible miners always envelop themselves in obscurity, and construct on all sides covered galleries as they advance into a building. M. Blanchard and M. de Quatrefages saw in La Rochelle the galleries made by them. They are tubes

formed of agglutinated material, which are stuck along the walls in the cellars and the apartments, or else suspended to the roof like stalactites. Certain parts of Agen and of Bordeaux have also suffered from the ravages of these insects, and elsewhere danger appears to be imminent. We are indebted to M. de Quatrefages for some interesting experiments on the termites of La Rochelle. Not only has the learned naturalist helped to make known to us the habits of these dark-loving insects, but he has also told us how to destroy them. Different substances have been tried in vain to stop these terrible ravages — essence of turpentine, arsenical soap, boiling lye, &c. M. de Quatrefages had recourse to gaseous injections. He tried successively binoxide of nitrogen, nitric acid, chlorine and sulphurous acid; chlorine, above all, fully answered his hopes. With pure chlorine he killed the termites instantaneously; mixed with nine-tenths of air, he suffocated them in half an hour. " For attacking the termites," says M. de Quatrefages, " one ought to choose by preference the period of their reproduction, so as to destroy the pregnant females. It is probable that, like their exotic congeners, the termites of France will endeavour to defend themselves by walling up the interior of their galleries at the first signs of an attack. The operator must then act with a great deal of promptitude, and direct the apparatus as much as possible into the very centre of their habitaticn, where the galleries are the broadest and the most numerous.

" With whatever care one acts, and wh.atever may be the success of a first attempt, it seems to me impossible to destroy in one campaign all the termites of a locality. In this, as in all operations of the same kind, a certain amount of perseverance is necessary, especially if it is in a town or in a country infested by them to a very great degree; in that case one will be forced to repeat the operation from time to time. When, on the contrary, the termites are already cantoned, it seems to me that the success ought to be lasting. This Ls fortunately the case at La Rochelle; and by knowing how to profit by it, one may doubtless prevent the spread of these pests, which at one time or another may attack the whole town." *

In 1864 the Lords of the British Admiralty addressed an inquiry to the Entomological Society of London, on the best means of preserving wood from the attacks of the Indian termites. In answer to this inquiry, the Entomological Society recommended many processes:

' ' Memoires sur la destruction des Termites." Annates des Sciences Nattirelles, 36 serie, tome xx., p. i^.

THE INSECT WORLD.

4i6

the injection of quicklime or of creosote, the apphcation of arsenical soap, &c. But it does not appear that these processes are infallibly efficacious, nor, above all, easy to employ.

Among other Neuroptera which undergo incomplete metamorphoses, we my mention, first, the genera Fer/a and Nemojira.'*

Fig. 384. bicaudata. — Larva of Perla Fig. 385.Nemoura.— Larva of Fig. 386. —(larva).Perla marginata

(Figs. 384, 385, and 386), which flutter about the banks of rivers and settle on stones, shrubs, and aquatic plants. Their larvae are naked, without cases, and always live in the water, hiding themselves under stones, to watch for small insects, for they are carnivorous. One sees them often balancing their bodies, holding on to a pebble. They go through the winter, and only become pupae in the spring. After moulting, they have the rudiments of wings. Very soon afterwards the pupae leave the water, and undergo their metamorphosis. The adult hves only a few days, for its mouth is not suited for re-

^•- From »^/uo, a thread; and ohph.^ a tail.— Ed.

ceiving food The larvae have, at the end of their bodies, two long threads, which remain in the perfect Perla (Fig. 387), but not in the

Fig. 387. — Perla bicaudata.

Fig. •Nemoura variegata. Fig. sSg.^Nemoura variegata (larva).

perfect Nemoura; the latter lose the two caudal hairs when they arrive at the adult state (Figs. 388, 389). One species of Perla is very common on the quays of Paris.

The EphemeridcE^ or May-Fly family, have long, slender bodies, 71

THE INSECT WORLD.

4i8

provided with two or three long silky hairs. Their name indicates the short duration of their existence. They appear in great numbers at certain seasons of the year. Their hatching takes place at sunset; they have coupled and laid their eggs by sunrise next day, and have ceased to live; so that the banks of rivers, of ponds, of lakes, are strewed with their bodies. Their number is sometimes so considerable that, according to Reaumur, the soil seems as if it were covered with snow, and they are gathered up for manure. The common Ephemera, or May-Fly {Ephemera vulgato,, Fig. 390), is of a brown colour, banded with yellow, and the wings smoky, with brown spots. These insects are remarkable for their elegant flight; they are continually rising and falling. When they move their wings they rise; but if their wings, though spread out, remain motionless, as also the silky hairs which form their tail, they fall again. They may be seen in myriads in places where there is much water. We have said that the Ephemerce live only for a few hours. This is the general rule; but their existence can be prolonged for ten or fifteen days by preventing their copulation. If, however, the duration of the life of these insects is so short when they have reached the perfect state, and when the conformation of the mouth pre-

Fig. 390. Ephemera vulgata, imago. vents them from taking any nourishment, their larva state is of very long continuance. Swammerdam says, in his curious Memoir, entitled " Vita Ephemeri," it is not less than three years.

The females lay their eggs in one single mass, and let them fall into the water, in the form of a packet. The larvae which come out of them are very active, and swim with great ease; but generally conceal themselves under the pebbles at the bottom. The sides of their abdomen are provided with gills, very much fringed, which serve them, not only for breathing the air uiider the water in the same way that fish do, but also for swimming. The larvas have, at the extremity of their body, two or three hairs, like the perfect insect. They hollow out galleries in the beds of rivers and ponds, and live on small insects.

419 neuropTerA.

The pupa (Fig. 392) differs only from the larva (Fig. 391) in having the rudiments of wings. When about to undergo their metamorphosis, they come out of the water and cling to plants, &c. The skin cracks on the back when it is dry, and there comes out a heavy insect, which flies feebly, and has opaque wings. It is still enveloped in a very thin skin, of which a last moult, after a few^ hours, frees it. This skin remains sticking to the plant on which the moulting was effected, preserving the shape of the insect. This moult is peculiar

►fit

Fig. 391. — Larva of an Ephemera. Fig. 392. — Pupa of an Ephemera.

to the EpJwjwcB; it is the transition from the false imago (pseudo-imago) to the imago.

In the same family is the genus Cloeon, whose larvae prey on minute insects. The Cloeon diptera (Fig. 393), which has only two wings, is often to be met with in houses, resting on the window panes and curtains. All these insects keep badly in collections; they lose their shape, and their members are so fragile that the least shock suffices to break them.

The LibellulcE^ or Dragon-Flies, are insects of a well-detined type.

Fig. 393.—Cloëon diptera.

THE INSECT WORLD.

420

The elegance of their shape, the grace of their movements, have won for them among the French their common appellation of " Demoiselles." They are always of largish size. Many are of bright and metallic colours, which are not inferior in beauty to those of butterflies. Their wings, of an extreme delicacy, always glossy and brilliant, present varied tints; sometimes they are completely transparent, and have all the colours of the rainbow. Often, the colour of the males differs from that of the

females. They may be seen fluttering about on the water during the whole summer, especially when the sun is at its highest. They fly with extreme rapidity, skimming over the water at intervals, and escaping easily when one wishes to catch them. Nothing is prettier than a troop of dragon-flies taking their sport on the side of a pond or on the banks of a river, on a fine summer's day, when a burning sun causes their wings to shine with most vivid colours. In the perfect state, as well as in that of the larva and the pupa, the Libellulæ are carnivorous. Their rapid flight makes them expert hunters, and their enormous eyes embrace the whole horizon. They seize, while on the wing, flies and butterflies, and tear them to pieces immediately with their strong mandibles. Sometimes, the ardour of the chase leading them on far from the streams, they are met with in the fields. The female lays her eggs in the water, from which emerge larvæ which remind one somewhat of the form of the insect, only their body is more compact and their head flattened. The larvæ and pupæ inhabit the bottom of ponds and streams, where, keeping out of sight in the mud, they seek for insects, molluscs, small fish, &c. If any prey passes within their reach, they dart forward, like a spring, a very singular arm, which represents the under lip. It is a sort of animated mask, armed with strong jagged pincers and supported by strong joints, the which, taken together, is equal to the length of the body itself. This mask acts at the same time as a lip

Page 68 of 88