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

We must still further mention here the Licas — beautiful insects of the same group, which are met with in South America, and whose males have an extraordinary head. They fly during the day round the great trees on which they live. Fig. 431 represents the Inca dathrata. The most commonly-known insect of the family with which we are now occupied is the cockchafer. The French word for cockchafer, hanneton, according to M. Mulsant, comes from the Latin, alitonus {i.e., having sonorous wings), which first became hallefon. Linn?eus gave them first the name o^ Melolontha, which they probably had among the Greeks, and which seems to be the case from this passage in Aristophanes, in his comedy of "The Clouds:" — "Let your spirit soar," says the Greek author, " let it fly whither it lists, like the Melolontha tied with a thread by the leg." We see that the ! habit of martyrising cockchafers is of very early date. The Common i Cockchafer (Fig. 432) is one of the greatest pests to agriculture. In ^1 its perfect state it devours the leaves of many trees, principally those

The insect wOi^ld. 446

of the elm; and so children call the fruit of the elm-tree by the name of " Pains d'Hanneton." But the destruction which ihey occasion in their perfect state is little when compared with that which is caused by their larvae — those white grubs so dreaded by agricul-turists.

Cockchafers make their appearance from the month of April, il

Fig. 431. — Inca clathrata.

the season is warm. But It is in the month of May that they show themselves in great quantities; and so they are called in Germany Maikafer (Maychafer). They are met with also in June. The duration of their life as a perfect insect is six weeks. They fear the heat of the day and the bright sunshine, so, during the day, they remain hooked on to the under surface of leaves. It is only early in the morning, and at sunset, that one sees the cockchafers fluttering round the trees which they frequent. They fly with rapidity, pro-

AA/ COLEOPTERA.

ducing a monotonous sound by the friction of their wings. But the cockchafer steers badly when it flies; it knocks itself at each instant against obstacles it meets with. It then falls heavily to the ground,

\ Fig. 432.— Cockchafer (^Melolontha V7clgar{s).

land becomes the plaything of children, who are constantly on the iook-out for them. There is a saying, "Etourdi comme un hannetoTi.'' What contributes still more to render the flight of these insects heavy and sustained only for a short time together is that they are obliged

to inflate themselves like balloons in order to rise into the air: it is a peculiarity which they share with the migratory locust. Before taking its flight, the cockchafer agitates its wings for some minutes, and inflates its abdomen with air. The French children, who

perceive this manoeuvre, say that the cockchafer ''compte ses ecus'' (is counting its money), and they sing to it this refrain, which has l3een handed down for many generations:—

'* Hanneton, vole, vole, Va-t'en a I'ecole."

A variation which we hear in the western provinces of France ii the following: — ** Barbot, vole, vole, vole, % Ton peie est a I'ecole, Qui m'a dit, si tu ne voles, II te coupera la gorge

Avec un grand couteau de Saint-George."

During the day the cockchafers remain under the leaves in a state of perfect immobility; for the heat which gives activity to other insects, seems, on the contrary, to stupefy them, and it is during the night only that they devour the leaves of elms, poplars, oaks, beech, birch-trees, &c. In years when their number is not very great, one hardly perceives the damage done by them; but at certain periods they appear in innumerable legions, and then whole parts of gardens or woods are stripped of their verdure, and present, in the middle of the summer, the appearance of a winter landscape. The trees thus stripped do not in general die; but they recover their former vigour with difticulty, and, in the case of orchard trees, remain one or two years without bearing fruit. It is principally the trees skirting woods, and situated along cultivated fields, which are exposed to the ravages of the cockchafer, because the larvae of these insects are developed in the fields. In the interior of forests they are never met with in great numbers. In certain years cockchafers multiply in such a frightful manner that they devastate the whole vegetation of a country. In the environs of Blois 14,000 cockchafers were picked up by children in a few days. At Fontainebleau they could have gathered as many in a certain year in as many hours. Sometimes they congregate in swarms, like locusts, and migrate from one locality to another, when they lay waste everything. To present an idea of the prodigious extant to which cockchafers increase under certain circumstances,

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we will give a few statistics: — In 1574, these insects were so abundant in England that they stopped many mills on the Severn. In 1688, in the county of Galway, in Ireland, they formed such a black cloud that the sky was darkened for the distance of a league, and the country people had great difficulty in making their hay in the places where they alighted. They destroyed the whole of the vegetation in such a way that the landscape assumed the desolate appearance of winter. Their voracious jaws made a noise which may be compared to that produced by the sawing of a large piece of wood, and in the evening the buzzing of their wings resembled the distant rolling of drums. The unfortunate Irish were reduced to the necessity of cooking their invaders, and, for the want of any other food, of eating them. In 1804, immense swarms of cockchafers, precipitated by a violent wind into the Lake of Zurich, formed on the shore a thick bank of bodies heaped up one on the other, the putrid exhalations from which poisoned the atmosphere. On May 18, 1832, at nine o'clock in the evening, a legion of cockchafers assailed a diligence on the road from Gournay to Gisors, just as it was leaving the village of Talmontiers; the horses, blinded and terrified, refused to advance, and the driver had to return as far as the village, to wait till this strange storm was over (Plate XI). M. Mulsant, in his " Monographie des Lamellicornes de la France," relates that in May, 1841, clouds of cockchafers traversed the Saône, from the south-east in the direction of the north-west, and settled in the vineyards of the Mâconnais. The streets of the town of Mâcon were so full of them that they were shovelled up with spades. At certain hours, one could not pass over the bridge without whirling a stick rapidly round and round, to protect oneself against their touch.

The coupling takes place towards the end of May, after which the males die; the females only surviving them for the time necessary to ensure the propagation of the species. The number of eggs which a female lays is from twenty to thirty. With her front leg she hollows out a hole in the ground from two to four inches in depth, and deposits her eggs, of a yellowish white and of the size of hemp-seed, therein. Her instinct leads her to choose soft, light, and well-manured soils, which are, at the same time, the best ventilated and the most fertile. We may conclude from this that cultivation and labour have made the cockchafer more common than it was formerly. It is the child of civilisation, the parasite of agriculture. In from four to six weeks after being laid, the little larvæ are hatched (Fig. 433), and immediately attack the roots of vegetables. They

THE INSECT WORLD.

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have a hard and horny head, and slender black legs, longer than in any other species of Scarahceides. Their body is composed of a whitish pulp under a transparent skin; the head and the mouth have

Fig. 433.— Larva of the Cockchafer {Melolontha vulgaris).

a reddish tinge. The length of their existence in this state is three, sometimes four years. From the egg laid in the month of June is hatched a larva, in the month of July. It increases in size during the last six months of the year, and continues to do so during the two

Fig. 434.~Pupa of the Cockchafer {Melolontha vulgaris).

following years, changing its skin many times during the period. Towards the end of the third year it changes into a pupa, after having surrounded itself with a cocoon consolidated with a glutinous froth and some threads of silk. The pupa (Fig. 434), is of a paie russety yeliow, with two little points at the extremity of its body; the elytra and the wings, lying down, cover the legs and the antenmv.

Towards the end of October the perfect insect is already marked out, but it is still soft and weak. It passes the winter in its hiding-place, hardens and becomes coloured at the end of the winter, and shows itself by degrees on the surface of the ground. In the month of April, three years after its birth, the cockchafer emerges from the earth, and commences its attack on the leaves of trees. This long duration of the development of the insect explains why we do not see them every year in the same number. When they have once appeared in great quantities, it is not for three years afterwards that we need expect to see their progeny again in proportionate numbers. It is, then, every three years that we have a cockchafer year like 1865, but in the intermediate years they are never very abundant. For the first year the little larvae do not eat much. They feed then principally on fragments of dung, and on vegetable detritus, and keep together in families. In winter they bury themselves deeply, so as to be secure against frost and floods. Next spring the want of a greater abundance of food forces them to disperse. They then make subterranean galleries in all directions, without, however, going far from the place where they were hatched. They begin attacking the roots which they find within their reach; the damage they do increasing with their size and the strength of their mandibles. Among roots, they seem to prefer those of the strawberry and of rose-trees; but they do not despise other vegetables, and attack legumes and cereals as well as bushes and plants. The ravages which they occasion are sometimes incalculable; market gardens are sometimes entirely devastated. Fields of lucerne have been seen partially destroyed by them; meadows of great extent lose their pasturage; oat fields die off before they have come to maturity; and many of the ears of corn fall before they are cut. In proportion as they increase in age and in strength — especially in their last year — do they attack also ligneous vegetation. When they have gnawed away the lateral roots of a young tree, the new shoots corresponding to them dry up. The larvae then attack the principal root, and thus bring about the death of the tree. There will be found round the roots of trees thus attacked immense numbers of these worms. M. Deschiens relates that he had seen six hectares of acorns, sown three times in the space of five years with a perfect result, entirely destroyed as many times by the larvae of the cockchafer. A nurseryman of Bourg-la-Reine suffered, in 1854, from the ravages of these terrible larvae, losses which he estimated at 30,000 francs. Others only preserved about a hundredth part of their plants. In Prussia they destroyed, in 1835, a considerable