Chapter IX: Coleoptera (2)

The most carnivorous of this group are the _Dytisci_ and the _Cybisters_. They may be called the sharks of the insect world. Nothing which lives in the water is safe against the voracity of the _Dytiscus_. They attack small molluscs, young fish, tadpoles, larvæ of insects, and suck greedily the bits of raw meat which are thrown to them. They may be kept in an aquarium for many years by feeding them on animal matter. Their oval-shaped body, with its sharp sides, permits them to cut through the water with great ease--the hind legs serving as oars. They are to be found in stagnant waters during the greatest part of the year, but principally in autumn. During the winter they bury themselves in the mud and under moss. The females lay their eggs in the water. The larvæ are long, swelling out at the middle, furnished with hairs, and grow rapidly. To undergo their metamorphosis into pupæ they bury themselves in the earth.

The perfect insects are amphibious, and fly from one pond to another to satisfy their voracious appetites. The most common species of this genus is the _Dytiscus marginalis_ (Fig. 474), of a dark greenish brown, yellowish on the sides. The elytra of the male are smooth; those of the female are fluted. The front leg of the male is provided with suckers. The larva is brown; the pupa of a dirty white.

The _Dytiscus marginalis_ sometimes attacks _Hydrophilus piceus_. It pierces it between the head and the thorax, that is, in the weak point of the cuirass, and devours it, in spite of its being the stronger. The largest of the _Dytisci_, the _Dytiscus latissimus_ (Fig. 476), is almost confined to the north of Europe. The _Cybisters_ abound especially in warm countries. The _Cybister Roeselii_ (Fig. 477), a European species, has the reputation of having been taken in England. This group contains also a great number of insects more or less resembling the preceding in their conformation and habits. We will confine ourselves to representing a few by figures.

The _Gyrinidæ_, which come very near to the _Dytiscidæ_, like water which is clear and a little agitated. They are small black insects, living in troops, and which swim with rapidity, describing incessantly capricious circles, which has gained for them the name of "Whirligigs." They are remarkable for the disposition of their eyes, which are double; so that the _Gyrinidæ_ seem to have four eyes. The lower ones look into the water and watch for the prey or the fish that advances as an enemy; whilst the upper eyes look upwards towards the air, and warn the insect of the approach of enemies from above. To escape from fish, the _Gyrinus_ jumps out of the water, and also makes use of its wings; to escape from birds it dives rapidly. This activity, and this double sight, make the capture of the _Gyrini_ a task of great difficulty. They must be caught with a net. At the moment of being seized they emit a milky and foetid liquid.

The females lay their eggs end to end, on the leaves of aquatic plants. The larvæ are long and narrow, and of a dirty white. They come out of the water at the end of the summer, and form for themselves a cocoon on the plants bordering the banks. After a month, the perfect insect is hatched, and plunges into the water. The _Gyrinus striatus_ (Fig. 496) is found in the waters of southern Europe.

All these species are of small size, and do not exceed a fifth of an inch in length; but in the tropics we find _Gyrini_ two-thirds of an inch long. One of these species, _distinctus_, exists in the little lake of Solazies, in Réunion Island, noted for its mineral waters. The visitors amuse themselves by fishing for this insect with a line baited with a bit of red cloth, which it attacks. It is found also in a mineral spring in Algeria. The _Epinecti_ (Fig. 498) are large _Gyrinidæ_ from Brazil, with very long front legs.

The carnivorous land insects _par excellence_--those which are most formidable, on account of their ravages and voracity--are the _Carabidæ_. This family, one of the most numerous of the Order Coleoptera, consists of insects with long legs, and armed with powerful mandibles, suited for tearing their victims to pieces. They are the lions and the tigers of the Coleoptera, whilst the _Necrophori_ and the _Silphæ_ play the part of hyænas and jackals. The eyes of the _Carabidæ_ are very prominent, which allows them to see their prey at a great distance. They take refuge under stones and under the bark of trees; but in fine weather they are also to be seen running along roads. Ardent and audacious, it is by no means rare to see them attacking species much bigger than themselves. The activity which distinguishes these insects is found also in their larvæ, which pursue living prey, instead of remaining shrouded in the midst of their food, like the larvæ of the _Scarabæidæ_.

These carnivorous insects are very numerous--a fortunate circumstance, considering the immense quantity of small noxious creatures, caterpillars, weevils, and an infinity of other parasites, the pests of agriculture, which they destroy. The popular prejudice, then, is to be regretted, which leads ignorant farmers to exterminate them. They ought, on the contrary, to be introduced into market gardens, as toads are, and as cats are into granaries. "The _Carabidæ_," says M. Michelet, "immense tribes of warriors, armed to the teeth, which, under their heavy cuirasses, have a wonderful activity, are perfect rural constabulary, day and night, without holidays or repose, protecting our fields. They never touch the smallest thing. They are occupied entirely in arresting thieves, and they desire no salary but the body of the thief himself." But ignorance destroys these useful hunters. Children, seduced by the richness of the elytra of the _Carabi_, amuse themselves in catching these vigilant protectors of our farms, without knowing the bad effect of what they are doing. Fortunately, education is spreading little by little in the country; the farmers begin to be awakened to their true interests, and to know how to distinguish the useful animals which it behoves them to preserve in their fields for the safeguard of their crops. In some places in France they have already made attempts to introduce the _Carabidæ_ and the _Cicindelidæ_ into gardens, and they have found them succeed very well.

The true _Carabi_ are to be known by their oval convex body, their long antennæ, and elegantly-carved thorax. They are, in general, of more massive forms than the _Cicindelidæ_, which compose a kindred family. The latter form, in some sort, the vanguard and the light troops; the others, the heavy battalions. The _Carabi_ coming out in general at night, or at least at twilight, and keeping themselves hidden under stones during the day, it is not easy to observe their manoeuvres.

The _Carabus auratus_ (Fig. 499), which abounds in fields and gardens on the Continent, may be considered as the type of this genus. It has elytra of a beautiful green, with three ribs, and the legs yellowish. When it is touched it disgorges a black and acrid saliva, and ejects from the abdomen a corrosive liquid of a disagreeable odour. It lives on the larvæ of other insects. It has been seen to attack even large insects, such as the cockchafer.

In England and the environs of Paris, _Carabus violaceus_ (Fig. 500), whose dress, of a sombre colour, is surrounded by shades of red and violet, is met with. In the Pyrenees many _Carabi_ with metallic reflections are found, whose beautiful colours are the delight of collectors; the _Carabus splendens_, the _Carabus rutilans_, &c. But the most beautiful insects of this tribe come from Siberia and the north of China. Let us mention, for example, the _Carabus smaragdinus_, of a beautiful grass-green; the _Carabus Vietinghovii_, of a beautiful blue black, bordered with azure, with a golden band, &c.

The _Carabus Adonis_ (Fig. 502) is not rare in Alsace, and is found on the banks of streams.

The long flat larvæ of the _Carabi_ live in the trunks of trees, among leaves, under moss, &c. They are active, and live on other insects. Fig. 504 represents the larva of the _Carabus auronitens_.

Another genus of the same family is _Calosoma_. They have wings under their elytra--the true _Carabi_ have not--which they use in passing from one tree to another.

In the month of June is to be found on oak trees the beautiful _Calosoma sycophanta_ (Fig. 508), the occasional occurrence of which in England is unquestionable; it is, however, presumed that the specimens have reached our shores from the Continent by flight, favoured by strong easterly winds. This insect is of a beautiful violet blue, having the antennæ and the legs black, and the elytra of a splendid golden green, with longitudinal streaks. According to Réaumur, the larva of the _Calosoma_ often chooses a home in the nest of the Procession-Moth Caterpillar (_Bombyx processionea_), on oak trees, and it very soon rids the tree which is infested by them.

The _Calosoma auropunctata_ is found in the south of France. Its larva (Fig. 507) devours snails, and establishes itself in their shells. These larvæ have been known to fill themselves so full of food as to become double their natural size, in which state they are sometimes devoured by those of their own species. A smaller kind, the _Calosoma inquisitor_, is very frequently to be met with in woods. Fig. 508 presents _Calosoma sycophanta_ pursuing a Bombardier (_Brachinus explodens_), which squirts out a vapour of pungent odour.

In the countries of the south-east of Europe, and in Asia Minor, one finds enormous _Carabidæ_, the _Procrustes_ and the _Proceri_, which attain nearly two inches in length, and whose integuments resemble very rough shagreen. One species alone is met with in France, the _Procrustes coriaceus_ (Fig. 509). In Austria is found the _Procerus gigas_ (Fig. 510).

The genus _Omophron_ (Fig. 511) contains small, almost globular _Carabidæ_ of a pale yellow, with green lines, and which live in the sand bordering rivers. The _Nebrias_ in general prefer mountainous countries. The largest species, the _Nebria arenaria_ (Fig. 512), is found all along the coast of the Mediterranean, and even on the western shores of France. But its colours grow paler as it advances northward on the African coast. It is of a bright yellow with black lines. The _Nebrias_ hide themselves either under masses of seaweed cast up by the waves, or under the stumps of trees cast ashore by the sea. When they are deprived of their place of shelter, they run away with such rapidity that it is very difficult to catch them. In Senegal is found the genus _Tefflus_ (Fig. 513), great black _Carabidæ_ with fluted elytra.

Other kindred genera are--_Damaster_ (Fig. 514), remarkable for elongated pointed elytra; _Anthia_ (Fig. 515), which is met with in sand in Africa and in India, and whose head is armed in a formidable manner; and _Campylocnemis_, of which _Schroeteri_ (Fig. 516), an Australian insect, of a bright black, attains to more than an inch and three quarters in length, and whose short serrated legs enable it to hollow out the ground. There is found on the coasts of the south of France a representative of this group in the _Scarites lævigatus_ (Fig. 517), which conceals itself in a hollow, like the cricket, and devours everything which comes within its reach.

The innumerable tribe of _Harpalidæ_ contains carnivorous beetles of very small size, sometimes of a bronze-green, sometimes black, either dull or shining, and which render great service to our gardens. Hidden under stones, in dry leaves, at the foot of trees, they attack a number of small insects, caterpillars, millepedes, &c., and thus exterminate a quantity of vermin. The _Harpalus æneus_ (Fig. 518), which is seen shining in the midst of the paving stones like a little bronze plate, is found everywhere. The _Galeritas_ (Figs. 519 and 520) are distinguished by their antennæ, which are thick at the base; they exhale a very strong odour: nearly all are peculiar to America. One of the most curious insects of this tribe is the _Mormolyce phyllodes_ of Java (Fig. 521) whose elytra project in such a manner as to give it the appearance of a leaf. It lives under bark. The larva and the pupa (Fig. 522) resemble those of other genera of which we have been speaking.

The next great family of the tribe of carnivorous beetles is composed of the _Cicindelidæ_--slender insects, with large prominent heads, very long legs, and which are very active in their movements. The _Cicindelidæ_ like sandy plains. When the sun shines they fly in a zig-zag manner, but their flight is not continued for long together. In dull weather they are to be seen running on the turf or hiding themselves in holes, and are met with on the sea-shore, where they are seen sometimes to pop up by hundreds. They live on flies and little shrimps, which abound on the sea-shore.

The _Cicindela campestris_ (Fig. 523), or Tiger Beetle, is of a beautiful green, spotted with white; the abdomen is of a bronze red. In this country it is the commonest of the genus. The _Cicindela hybrida_, of a dull green, relieved by light bands, inhabits sandy woods. The _Cicindela maritima_ differs from the preceding. The _Cicindela sylvatica_, which flies very well, is not easy to catch, and is to be often met with in the warm glades of the forest of Fontainebleau and at Montmorency; it is not unfrequent here. Its colour is brown, spotted with white; it diffuses a strong smell of the rose, to which succeeds, on being seized, the acrid odour of the secretion which it disgorges. We here represent the _Cicindela Dumoulinii_ (Fig. 524), the _Cicindela rugosa_ (Fig. 525), the _Cicindela scalaris_ (Fig. 526), the _Cicindela heros_ (Fig. 527), the _Cicindela quadrilineata_ (Fig. 528), and the _Cicindela capensis_ (Fig. 529).

The ferocity of these insects is remarkable. They quickly tear off the wings and legs of their victim, and suck out the contents of its abdomen. Often, when they are disturbed in this agreeable occupation, not wishing to leave it, they fly away with their prey; their flight, however, is not sufficiently powerful to allow of their carrying to any great distance such a heavy burden. When a _Cicindela_ is seized between the fingers, it moves about its mandibles and endeavours to pinch, but its bite is inoffensive and not very painful. They are prodigiously active in running. Armed with jaws which are powerful enough to overcome their victims and to seize them at once, they can dispense with stratagem.

Their larvæ (Fig. 530) are soft, and have short legs. To satisfy their voracity they are obliged to lie in ambush in holes. They are two-thirds of an inch long; their head is horny and in the form of a trapezium. The first segment is also horny, and of a metallic green. The eighth has a pair of tubercles with hooks, of which the larva makes use in ascending and descending its vertical hole, like a sweep in a chimney. This hole (Fig. 531) is a foot or more deep. To dig it, the larva employs its mandibles and its legs in the following manner: it twists itself round, loads with earth the flat surface which covers its head, climbs along the chimney by twisting itself into the form of the letter Z, and thus transports its load, as a bricklayer's labourer carries a hod of mortar up a ladder. Arrived at the mouth of the hole, it throws to a distance the rubbish with which its head is loaded; or, if too heavy, it simply deposits it, pushing it away as far as possible. It is difficult to watch their proceedings, for they are very mistrustful, and retire immediately into their hole when alarmed. They remain in ambush at the entrances of these subterranean passages, which they hermetically seal with their head and thorax. It is a species of pitfall which sets itself in motion the moment anything endeavours to pass it. The unfortunate who ventures is precipitated into the well, and the _Cicindela_ forthwith devours it. These habits remind one of those of the ant-lion. When the time arrives for the metamorphosis, the larva of the _Cicindela_ enlarges the bottom of its hole, and stops up the entrance with earth before changing. The pupa (Figs. 532, 533) is of a pale glossy yellow, covered with small spines. The metamorphosis takes place between August and October; the perfect insect emerges in spring.

Nearly akin to the _Cicindelas_ are the _Tetrachas_ (Figs. 534, 535, 536), from Africa and tropical America; the _Manticoras_ (Fig. 537), which are distinguished by their robust and thick-set appearance; the _Pogonostomas_ (Fig. 538), which live in Madagascar; the _Ctenostomas_, peculiar to America (Fig. 539), remarkable for the length of their pendent and bristly palpi; the _Omus_, of California; the _Therates_ (Fig. 540), insects of the East Indian Islands, &c.

The tribe of _Tenebrionidæ_, called formerly _Melasomas_, because they are nearly all black, resembles in some points the _Carabici_. They seek after dark places, and avoid the light, and are found on the ground under stones; their movements are slow, and they walk with difficulty. The best-known insect of this group is the _Blaps_, of repulsive smell, inhabiting dark damp places, such as cellars, and only coming out of its retreat during the night. The elytra are joined together, and they have no wings. The vulgar regard them as an omen of ill-luck. Fig. 541 represents the _Blaps obtusa_. According to the report of a traveller, the women in Egypt eat the _Blaps sulcata_ cooked with butter, to make them fat. They are employed also against the ear-ache, the bite of scorpions, &c.

Another genus of the same family is the _Tenebrio_ (Fig. 542), of a blackish-brown, with the elytra striated, and of half an inch in length. The larvæ, the well-known meal-worms, live in flour; they are cylindrical, and of a light tawny colour (Fig. 542). The insect which is considered as a type of the tribe of the _Pimelides_ is the _Pimelia bipunctata_, which is common in the south of France.

We come now to the tribe of blistering beetles, of which the best known is the Cantharides (_Cantharis_ or _Lytta_). These insects are generally of soft consistency, and their elytra very flexible. A few remain constantly on trees. All are very brisk and active. When swallowed they are a dangerous poison, but are used in medicine for making blisters.

The Cantharides of commerce (_Cantharis_ [_Lytta_] _vesicatoria_) are of a beautiful green, attain to a size of four-fifths of an inch, and are found on ash-trees, lilacs, and other shrubs. Commerce for a long time brought them from Spain, and some still come from that country; hence the common name of _Spanish fly_. As they live in great numbers together, collecting them is easier and less expensive than would be that of other species of the same family which are not gregarious, but which have the same medicinal properties. The presence of the Cantharides is manifested by the strong penetrating odour which they diffuse to some distance. When, by aid of this smell, they are discovered, generally settled on an ash, they are collected in the following manner:--Very early in the morning a cloth of light tissue is stretched out at the foot of the tree, and the branches are shaken, which causes the insects to fall (PLATE XII.). These, numbed by the cold of the night, do not try to escape. When there is a sufficient quantity, the four corners are drawn up and the whole plunged into a tub of vinegar diluted with water. This immersion causes the death of the insects. They then carry them to a loft, or under a very airy shed. To dry them they spread them out on hurdles covered with linen or paper, and from time to time, to facilitate the operation, they are moved about, either with a stick or with the hand, which is more convenient; but it is then necessary to take the precaution of putting on gloves, for, if touched with the naked hand, they would cause more or less serious blisters. The same precaution must be observed in gathering them.

When the Cantharides are quite dry, they put them into wooden boxes or vessels of glass or earthenware hermetically sealed, and preserve them in a place protected from damp. With these precautions, they may be kept for a long while without losing any of their caustic properties. Dumeril made blisters of Cantharides which had been twenty-four years in store, and which had lost none of their energy. When dry, they are so light that a kilogramme contains nearly 13,000 insects. Aretius, a physician who flourished at Rome in the first century of our era, seems to have been the first to employ Cantharides, reduced to powder, as a means of vesication. Hippocrates administered them internally in cases of dropsy, apoplexy, and jaundice. But it is pretty nearly established that the Cantharides of the ancients were not the same species used at the present day; they were, probably, a kindred species, the _Mylabris chicorii_. A blistering principle has been extracted from these insects, called _Cantharadine_. This organic product presents itself under the form of little shining flakes, without colour, soluble in ether or oil. One atom of this matter applied to the skin, and particularly to the lower lip, makes the epidermis rise instantaneously, and produces a small blister filled with a watery liquid. In spite of the corrosive principle which the _Cantharis_ contains, it is attacked, like other dried insects, by the _Dermestes_ and the _Anthrenus_, which feast on them without suffering the smallest inconvenience.

The _Stylopidæ_, for which Kirby,[122] in 1811, instituted a distinct Order, which he called _Strepsiptera_, in allusion to the contortion of the elytra, and to which Latreille[123] subsequently applied the name of _Rhipiptera_, are, perhaps, the most anomalous of all insects. Great diversity of opinion has existed respecting their affinities; but modern systematists, with but few exceptions, concur in referring them to the Order _Coleoptera_, and locating them in proximity to _Meloë_. In the larva state, all the known species of the family inhabit the bodies of hymenopterous insects of the genera _Andrena_, _Polistes_, &c., in this particular resembling the dipterous genus _Conops_, which inhabits the body of humble bees,[124] and apparently in no way inconveniencing their victims; a fact which has been accounted for on the supposition that their existence in the larva state is but short, and that their attacks being directed against the abdomen, and not the thorax, the seat of life in insects, their presence does not affect the activity of the victim. The larva has a soft fusiform body, surmounted by a somewhat globose head. While feeding, the head is towards the base of the abdomen; but on changing to a pupa, this position is reversed, and the head--at first of light brown, but which after a short time becomes black--thrust out between the plates of the abdomen.

[122] "On a new Order of Insects," _Linn. Trans._, vol. xi.

[123] In Cuvier, "Le Règne Animal," ed. i., tome iii., p. 584.

[124] See p. 69.

The imagos, which are of small size, namely, about the eighth of an inch long, are found during May and June. They have four wings, but the anterior pair, of hard texture, somewhat resembling elytra, but hardly answering to them in structure, are very poorly developed, and curled round the front pair of legs, hence the name bestowed, by Kirby, from [Greek: strepssis], a twisting, and [Greek: pteron], a wing; the posterior wings are fully developed, and fold up like a fan, whence the Order received the name of _Rhipiptera_ from Latreille. The eyes, the facettes of which are few in number, are placed on a footstalk, whence the name of the genus _Stylops_. The parts of the mouth connect the Strepsiptera with the mandibulated insects, although by some supposed to bear analogy by their functions to those parts in the Diptera. The male only is winged; the female is very like an apodal larva, the larva being an active hexapod.

The family _Stylopidæ_ is divided into four genera, of which two only, _Xenos_ and _Stylops_, were described by Kirby in the essay referred to above. First, _Xenos_, from [Greek: xenos], a guest, the most prolific in species, of which _Xenos Rossii_, sometimes called _vesparum_, may be taken as the type. Secondly, _Elenchus_, of which _Elenchus Walkeri_ is the type. Thirdly, _Stylops_ (Fig. 543), parasitical on various species of _Andrenæ_, of which _Stylops Melittæ_, having a fleshy abdomen and the wings longer than the body, may be considered typical: and lastly, _Halictophagus_, of which only one species, infesting _Halictus æratus_[125] named _Halictophagus Curtisii_, is known to exist, and which makes its appearance in the month of August.

[125] _Halictus_ and _Andrena_ are two genera of Bees.

These singular insects are found in various parts of the world--Europe, Australia, and America. They were discovered by Professor Peck almost simultaneously with Mr. Kirby's discovery in this country, and to whom he sent specimens of a species which has received the name of _Xenos Peckii_ lately, in New Zealand and elsewhere.

Siebold, in 1843, having obtained some eggs, was able to observe the larvæ, and he soon discovered that the females of Stylops, one of the Strepsiptera, were blind, had no legs, and always retained the appearance of larvæ, and that they never quitted the bodies of those insects, in which they pass a parasitic existence. George Newport paid great attention to the history of these curious insects, and when he wrote his article, "Insecta," in the "Cyclopædia of Anatomy and Physiology," four distinct genera of these minute parasites had already been discovered. One of the largest species (_Stylops Spencii_) is scarcely more than two lines in length, while the smallest species yet known is not more than two-thirds of a line, or scarcely a line in breadth with its wings expanded. They undergo metamorphosis; and the males, when they have become perfect insects, fly and roam about, but the females are condemned to a perfectly quiet life. The head and the thoracic segments of the bodies of these last are united completely, but the abdomen, which is very large, always remains soft, so that the whole of the body only appears to be formed of two portions. They are ovo-viviparous insects, and the young larvæ escape as such from the body of the mother. They are active creatures, and, being furnished with long legs, crawl over the hairs and skin of the hymenopterous insect they are parasitic upon. They behave like the larvæ of Meloë and Sitaris, whose peculiar methods of life have been noticed in our description of the Coleoptera. Clinging on to a wasp or a bee, they are carried off, and finally arrive in the nest or hive, as the case may be, and there they attack the larvæ. When once fixed upon the hymenopterous larvæ, they undergo a change of skin, and their shape then becomes totally different, and their legs are atrophied. But these parasites being exceedingly small, do not kill the larvæ; they suck their juices, after the manner of the Ichneumons, and do not interfere with the metamorphoses of the insects upon which they are parasitic. On the right hand, in the accompanying engraving (Fig. 544), there is a larva much magnified, lately born, and climbing upon the hair of one of the Hymenoptera, and on the left hand there is a perfect female insect, very much magnified, with ovo-viviparous larvæ within its abdomen, and between the two figures there is a representation of a larva of the natural size. It is evident, however, that ova may be expelled from the mother before they are hatched.

Packard describes the curious history of the female Stylops, which he found parasitic on one of the bees. He caught the bee, and on examining it he noticed a pale reddish-brown triangular mark on the abdomen, and this was the flattened head and thorax of a female Stylops. The creature is included in the body of the bee, and is nourished by its juices. The head and thorax of the parasite were noticed to be soldered into a single flattened mass, the baggy hind body being greatly enlarged, like that of the female white ant. On carefully drawing out the whole body from the bee the mass was found to be very extensible, soft, and baggy, and on examining it under a high power of the microscope, multitudes of very minute larvæ were observed, and they began to issue out from the body of the parent all alive, and not as eggs. The male of this _Stylops childreni_ is totally unlike its partner, having large hind wings, and being able to fly, as has already been noticed. It appears, then, that the larvæ are hatched or crawl out of the body of the mother on to the body of the bee, and are then transported to its nest; then they enter the body of the bee larva, and live upon its fatty matter. The male Stylops is turned into a pupa within the bee, and so is the female; but after the second metamorphosis the male flies off, leaving his wingless partner imprisoned for life, and she usually dies immediately after giving birth to her myriad offspring (Packard). The female respires by peculiarly arranged tracheæ, and absorbs nourishment through her skin as well as by means of an alimentary canal, which ends in a blind sac. All the beauties of the female, so far as they are visible to the male, consist in the tiny patch which appears just without the body of the unfortunate bee, and the ova collect in a space which opens between the united head and body and the abdomen.

The genus _Mylabris_ corresponds most in structure, in appearance, and in properties, to _Cantharis_, whose place they take in the East, in China, and in the south of Europe. They are found in clusters on the flowers of chicory, thistles, &c. The _Mylabris chicorii_, common enough in France, especially in the south, is of small size, whilst the other species are rather large. It is black, hairy, with a large yellowish spot at the base of each elytron, and two transverse bands of the same colour.

Another genus of this family is _Meloë_, with very short elytra, and without wings. They walk slowly and with difficulty on low plants, the female dragging along an enormous abdomen filled with eggs. They are generally observed in spring. In Germany they give them the name of _Maiwurm_ (Mayworm). Their succulence would expose them, without doubt, to the voracity of birds and of insect-eating Mammifers if they had not the power of exuding at will, in the moment of danger, from all their articulations, an unctuous humour of a reddish-yellow colour, the odour and probably also the caustic properties of which repel the aggressor. The females lay their eggs underground, and out of these come forth larvæ of a strange shape. Swallowed by cattle, they cause them to swell and die. It is for this reason that Latreille has given it as his opinion that these insects are the _Buprestis_ of the ancients, of which the law of Cornelius speaks, "Lex Cornelia de sicariis et veneficis." But the name of _Buprestis_ was applied by Linnæus to a genus of which we shall treat farther on, and it has been generally adopted by naturalists.

The commonest among the _Meloës_ is the _Meloë proscarabæus_, which is to be found in abundance, in the month of April, in the meadows near the bridge of Ivry in the environs of Paris. The metamorphoses of the insects of this family had remained for a long time surrounded with an impenetrable veil of mystery, but the researches of Newport in England, and of M. Fabre (of Avignon) in France, has made known in our days, phases, extremely curious, under which are accomplished the metamorphoses of the _Meloë cicatricosus_, and of the _Sitaris humeralis_, a species which belongs to the same family.[126] These observations, of which we are about to give a rapid summary, will probably help towards unravelling the first states of _Cantharis_.

[126] "Annales des Sciences Naturelles," 1857, 4e série, tome
vii., p. 300.

The _Sitaris humeralis_ (Fig. 545) takes no nourishment when arrived at the perfect state. When the female has been impregnated, she lays at the entrance of the nest of a solitary bee from 2,000 to 3,000 small whitish eggs, stuck together in shapeless masses. A month afterwards there come out of these eggs very small larvæ, of a shiny dark green, hard-skinned, armed with strong jaws, and long legs and antennæ (Fig. 546). These are the first larvæ. They remain motionless, and without taking food, till the following spring. At this period are hatched the male bees, which precede the appearance of the females by a month. As the bees come out of their nests, these larvæ hook themselves on to their hairs, and pass them to the females, at the coupling period. When the male bees have built the cells, and furnished them with honey, the female, as we know, deposits in each an egg. Immediately the larvæ of the _Sitaris_ let themselves fall on these eggs, open them, and suck their contents. Then they change their skin, and the second larva appears. This one gets into the honey, on which it feeds for six weeks. It is blind, whereas the first larva was provided with four eyes, no doubt to enable it to see the bees which were to serve as its conductors, in like 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 the _pseudo-nymph_ (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 _Ephemeræ_. The larvæ of the _Sitaris_ had for a long time been remarked clinging on to the hairs of the _Anthophoras_, but they were always taken for _Acari_, and they had been described as such.

The _Lampyridæ_ have the elytra weak and soft, like the insects of the preceding tribe. In their perfect state they frequent flowers. The larvæ 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 have for their object to reveal their presence to the opposite sex, for 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. Some chemical experiments have been made to ascertain the nature or the composition of the humour which produces this strange effect; but up to this moment, they have only enabled us to discover that the luminous action is more powerful in oxygen, and ceases in gases incapable of supporting combustion. In the most common species, the _Lampyris noctiluca_, or glow-worm, the phosphorescence is of a 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 larvæ much, only they have the head more conspicuous, and the thorax buckler-shaped, like the male. The larvæ feed on small molluscs, hiding in the snails' shells, after having devoured the inhabitant. They also possess the phosphorescent property in a less degree than the adult females. The female pupa resembles the larva; the pupa of the male, on the contrary, has the wings folded back under a thin skin. The perfect insect appears towards the autumn.

The Glow-worm (_Lampyris noctiluca_, Fig. 550) is of a brownish yellow. It is common in England. In a kindred species, the _Luciola Italica_, the two sexes are winged, of a tawny-brown, and equally phosphorescent. They are met with in great numbers in Italy, and the lawns are covered with them. Other insects of this family are without the faculty of emitting light; as, for example, the genus _Lycus_, of brilliant colours, which are met with in Africa and India. One of the finest is the _Lycus latissimus_.

_Drilus_ is another genus, comprising insects of very singular habits. The type is the _Drilus flavescens_. The male--a quarter of an inch long, black and hairy, with elytra of a testaceous yellow, and with pectinated antennæ--for a long time was alone known. The 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 understood. Mielzinsky, a Polish naturalist established at Geneva, found the _Drilus_ in the larva state in the shell of the _Helix nemoralis_. These larvæ devour the snail whose dwelling they occupy, as do the larvæ of the _Lampyris_. Mielzinsky saw them emerge, but obtained only females, which differed scarcely at all from the larvæ from which they proceeded. He made a separate genus of them, under the denomination of _Cochleoctonus_, and called the species _Vorax_. Later, 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 larvæ. 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, so unlike each other, belong to the same species.

The larva of the _Drilus flavescens_ 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 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 flavescens_ 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 Mauritanicus_. The larva of this insect lives at the expense of the animal of the _Cyclostoma Volzianum_, 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 he is able the fatal moment. But when, 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 _Eucinetides_, and the _Cebrionides_ belong to the same family. The first is exotic.

The _Elateridæ_ are rather large insects, often of hard texture, having the prosternum prolonged into a point (Figs. 551 and 552), and the antennæ 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 larvæ of the genus _Elateridæ_ (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 larvæ 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 _Elateridæ_, attaining to a length of two inches; and are inhabitants of Africa and Australia.

In America are found phosphorescent _Elateridæ_. These are the _Pyrophori_, 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 noctilucus_ (Fig. 554) is very common in Havannah, in Brazil, in Guyana, 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 battalion, 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 tookest it'"[127] The 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 living 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 refinement 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 _soirée_, 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 America to Paris, probably in some old piece of wood which happened to be on the vessel, caused great terror to the inhabitants of the Faubourg St. Antoine, when they saw it flying in the evening, glittering in the air. In 1864 a number of Cucuyos were brought from Mexico to Paris by M. Laurent, captain of the frigate _La Floride_. An experiment, made in the laboratory of the École Normal, showed that the spectrum of their light is continuous, without any black rays; it differs, besides, from the spectrum of the solar light by a greater intensity of the yellow colour. The light is produced probably as it is in the case of the _Lampyris_, by the slow combustion of a substance secreted by the animal. The Cucuyo can, nevertheless, at will, increase or diminish the splendour of this light by means of membranes which it superposes, like screens, in front of the phosphorescent bumps which it has on its thorax.

[127] "L'Insecte."

In the Indies, and in China, the women use for dressing their hair with, or as ear-rings, another Coleopteron of the same tribe, which begins even to be employed for this purpose by the women of the south of France. It is a _Buprestis_, of splendid colours, and of metallic brightness. Linnæus, as we said above, gave to it, wrongly, the name of _Buprestis_, which among the ancients served to designate a very different insect, the _Meloë_, of the family of the _Cantharidæ_; but modern naturalists have allowed this illegitimate title.

The _Buprestidæ_ walk heavily, but fly with the greatest ease during the heat of the sun, and settle on the trunks of trees exposed to its rays. In Europe, and especially in the North, they are very rare, and of very small size. They must be looked for on birch-trees, whose white colour seems to attract them. In the hottest parts of the world they are very abundant, of large dimensions, and adorned with sparkling colours. They do not jump, and are not endowed with the phosphorescent property. Their larvæ have no legs, are elongate, whitish, of a fleshy consistency, with the first ring of their bodies very much broadened. They live in the trunks of trees, between the bark and the wood, hollowing out for themselves irregular galleries, and remaining sometimes in this state for ten years before metamorphosing. Laporte de Castelnau and Gory have described and made drawings of about 1,300 species of _Buprestidæ_. Fig. 555 represents the _Buprestis imperialis_. The _Buprestis albosparsa_, the genera _Julodis_, the _Chrysochroas_, and the _Trachys_ belong also to the great family of _Buprestidæ_. The _Cleridæ_ are connected with the preceding. They have the thorax narrower than the elytra, and rather long; their integuments are less solid than those of the _Elateridæ_ and the _Buprestidæ_. The latter are phytophagous, the former carnivorous. The principal type of this family is the _Clerus formicarius_, russety, with the head and legs black, whose larva lives at the expense of the larvæ of the weevil. Another genus, the _Necrobia_, which lives on dried animal matter, has become celebrated, as it was the cause of the salvation of the greatest entomologist of France. The name of _Necrobia_ (from [Greek: nekros] and [Greek: biôs]) does not mean "which lives on dead bodies," but it means "life in death." Here is the story of which this name is destined to preserve the remembrance, and which Latreille himself has related in his "Histoire des Insectes." Before 1792, Latreille was known only from some memoirs which he had published on insects. He was then priest at Brives-la-Gaillarde, and was arrested with the curés of Limousin, who had not taken the oath. These unfortunates were then taken to Bordeaux in carts, to be transported to Guyana. Arrived at Bordeaux in the month of June, they were incarcerated in the prison of the Grand Séminaire till a ship should be ready to take them on board. In the meanwhile, the 9th Thermidor arrived, and caused the execution of the sentence which condemned the priests who had not taken the oath to transportation to be for a while suspended. However, the prisons emptied themselves but slowly, and those who had been condemned had none the less to go into exile, only their transportation had been put off till the spring.

"Latreille remained detained at the prison of the Grand Séminaire. In the same chamber which he occupied there was at the time an old sick bishop, whose wounds a surgeon came each morning to dress. One day as the surgeon was dressing the bishop's wounds, an insect came out of a crack in the boards. Latreille seized it immediately, examined it, stuck it on a cork with a pin, and seemed enchanted at what he had found.

"Is it a rare insect, then?" said the surgeon.

"Yes," replied the ecclesiastic.

"In that case you should give it to me."

"Why?"

"Because I have a friend who has a fine collection of insects, who would be pleased with it."

"Very well, take him this insect; tell him how you came by it, and beg him to tell me its name."

The surgeon went quickly to his friend's house. This friend was Bory de Saint Vincent, a naturalist who became celebrated afterwards, but who was very young at that time. He already occupied himself much with the natural sciences, and in particular with the classing of insects. The surgeon delivered to him the one found by the priest, but in spite of all his researches, he was unable to class it.

Next day the surgeon having seen Latreille again in his prison, was obliged to confess to him that in his friend's opinion this Coleopteron had never been described. Latreille knew by this answer that Bory de Saint Vincent was an adept. As they gave the prisoner neither pen nor paper, he said to his messenger, "I see plainly that M. Bory de Saint Vincent must know my name. You tell him that I am the Abbé Latreille, and that I am going to die at Guyana, before having published my 'Examen des Genres de Fabricius.'"

Bory, on receiving this piece of news, took active steps, and obtained leave for Latreille to come out of his prison, as a convalescent, his uncle Dayclas and his father being bail for him, and pledging themselves formally to deliver up the prisoner the moment they were summoned to do so by the authorities. The vessel which was to have conducted Latreille to exile, or rather to death, was getting ready whilst these steps were being taken, and while Bory and Dayclas were obtaining leave for him to come out of prison. This was quite providential, for it foundered in sight of Cordova, and the sailors alone were able to save themselves. A little time afterwards his friends managed to have his name scratched out from the list of exiles. It is thus that the _Necrobia ruficollis_ was the saving of Latreille.

The tribe of weevils is even much more numerous than that of the _Elateridæ_ and the _Buprestidæ_. One may know them by their head prolonged into a snout or trunk, by their rudimentary mouth, and by their elbowed antennæ. About twenty thousand species are said to exist. They feed on vegetables. Their larvæ are soft, whitish worms, without legs, with very small heads, and live in the interior of the stalks or seeds of plants, often occasioning enormous damage. They are one of the plagues of agriculture. Each of our dry vegetables, each variety of our cereals, has in this immense family its particular enemy.