Social Life in the Insect World Part 5

Let us return to the larva. Sooner or later, as we have seen, it falls to the ground, either by accident or intention. The tiny creature, no bigger than a flea, has preserved its tender newly-hatched flesh from contact with the rough earth by hanging in the air until its tissues have hardened. Now it plunges into the troubles of life.

I foresee a thousand dangers ahead. A mere breath of wind may carry this atom away, and cast it on that inaccessible rock in the midst of a rut in the road which still contains a little water; or on the sand, the region of famine where nothing grows; or upon a soil of clay, too tenacious to be tunnelled. These mortal accidents are frequent, for gusts of wind are frequent in the windy and already severe weather of the end of October.

This delicate organism requires a very soft soil, which can easily be entered, so that it may immediately obtain a suitable shelter. The cold days are coming; soon the frosts will be here. To wander on the surface would expose it to grave perils. It must contrive without delay to descend into the earth, and that to no trivial depth. This is the unique and imperative condition of safety, and in many cases it is impossible of realisation. What use are the claws of this tiny flea against rock, sandstone, or hardened clay? The creature must perish if it cannot find a subterranean refuge in good time.

Everything goes to show that the necessity of this first foothold on the soil, subject as it is to so many accidents, is the cause of the great mortality in the Cigale family. The little black parasite, the destroyer of eggs, in itself evokes the necessity of a large batch of eggs; and the difficulty which the larva experiences in effecting a safe lodgment in the earth is yet another explanation of the fact that the maintenance of the race at its proper strength requires a batch of three or four hundred eggs from each mother. Subject to many accidents, the Cigale is fertile to excess. By the prodigality of her ovaries she conjures the host of perils which threaten her offspring.

During the rest of my experiment I can at least spare the larvae the worst difficulties of their first establishment underground. I take some soil from the heath, which is very soft and almost black, and I pa.s.s it through a fine sieve. Its colour will enable me more easily to find the tiny fair-skinned larvae when I wish to inform myself of pa.s.sing events; its lightness makes it a suitable refuge for such weak and fragile beings. I pack it Pretty firmly in a gla.s.s vase; I plant in it a little tuft of thyme; I sow in it a few grains of wheat. There is no hole at the bottom of the vase, although there should be one for the benefit of the thyme and the corn; but the captives would find it and escape by it.

The plantation and the crop will suffer from this lack of drainage, but at least I am sure of recovering my larvae with the help of patience and a magnifying-gla.s.s. Moreover, I shall go gently in the matter of irrigation, giving only just enough water to save the plants from peris.h.i.+ng.

When all is in order, and when the wheat is beginning to shoot, I place six young larvae of the Cigale on the surface of the soil. The tiny creatures begin to pace hither and thither; they soon explore the surface of their world, and some try vainly to climb the sides of the vase. Not one of them seems inclined to bury itself; so that I ask myself anxiously what can be the object of their prolonged and active explorations. Two hours go by, but their wanderings continue.

What do they want? Food? I offer them some tiny bulbs with bundles of sprouting roots, a few fragments of leaves and some fresh blades of gra.s.s. Nothing tempts them; nothing brings them to a standstill.

Apparently they are seeking for a favourable point before descending into the earth. But there is no need for this hesitating exploration on the soil I have prepared for them; the whole area, or so it seems to me, lends itself excellently to the operations which I am expecting to see them commence. Yet apparently it will not answer the purpose.

Under natural conditions a little wandering might well be indispensable.

Spots as soft as my bed of earth from the roots of the briar-heather, purged of all hard bodies and finely sifted, are rare in nature. Coa.r.s.e soils are more usual, on which the tiny creatures could make no impression. The larva must wander at hazard, must make a pilgrimage of indefinite duration before finding a favourable place. Very many, no doubt, perish, exhausted by their fruitless search. A voyage of exploration in a country a few inches wide evidently forms part of the curriculum of young Cigales. In my gla.s.s prison, so luxuriously furnished, this pilgrimage is useless. Never mind: it must be accomplished according to the consecrated rites.

At last my wanderers grow less excited. I see them attack the earth with the curved talons of their fore-limbs, digging their claws into it and making such an excavation as the point of a thick needle would enter.

With a magnifying-gla.s.s I watch their picks at work. I see their talons raking atom after atom of earth to the surface. In a few minutes there is a little gaping well. The larva climbs downwards and buries itself, henceforth invisible.

On the morrow I turn out the contents of the vase without breaking the mould, which is held together by the roots of the thyme and the wheat. I find all my larvae at the bottom, arrested by the gla.s.s. In twenty-four hours they had sunk themselves through the entire thickness of the earth--a matter of some four inches. But for obstacle at the bottom they would have sunk even further.

On the way they have probably encountered the rootlets of my little plantation. Did they halt in order to take a little nourishment by implanting their proboscis? This is hardly probable, for a few rootlets were pressed against the bottom of the gla.s.s, but none of my prisoners were feeding. Perhaps the shock of reversing the pot detached them.

It is obvious that underground there is no other nourishment for them than the sap of roots. Adult or larva, the Cigale is a strict vegetarian. As an adult insect it drinks the sap of twigs and branches; as a larva it sucks the sap of roots. But at what stage does it take the first sip? That I do not know as yet, but the foregoing experiment seems to show that the newly hatched larva is in greater haste to burrow deep into the soil, so as to obtain shelter from the coming winter, than to station itself at the roots encountered in its pa.s.sage downwards.

I replace the ma.s.s of soil in the vase, and the six exhumed larvae are once more placed on the surface of the soil. This time they commence to dig at once, and have soon disappeared. Finally the vase is placed in my study window, where it will be subject to the influences, good and ill, of the outer air.

A month later, at the end of November, I pay the young Cigales a second visit. They are crouching, isolated at the bottom of the mould. They do not adhere to the roots; they have not grown; their appearance has not altered. Such as they were at the beginning of the experiment, such they are now, but rather less active. Does not this lack of growth during November, the mildest month of winter, prove that no nourishment is taken until the spring?

The young Sitares, which are also very minute, directly they issue from the egg at the entrance of the tubes of the Anthrophorus, remain motionless, a.s.sembled in a heap, and pa.s.s the whole of the winter in a state of complete abstinence. The young Cigales apparently behave in a very similar fas.h.i.+on. Once they have burrowed to such depths as will safeguard them from the frosts they sleep in solitude in their winter quarters, and await the return of spring before piercing some neighbouring root and taking their first repast.

I have tried unsuccessfully to confirm these deductions by observation.

In April I unpotted my plant of thyme for the third time. I broke up the mould and spread it under the magnifying-gla.s.s. It was like looking for needles in a haystack; but at last I recovered my little Cigales. They were dead, perhaps of cold, in spite of the bell-gla.s.s with which I had covered the pot, or perhaps of starvation, if the thyme was not a suitable food-plant. I give up the problem as too difficult of solution.

To rear such larvae successfully one would require a deep, extensive bed of earth which would shelter them from the winter cold; and, as I do not know what roots they prefer, a varied vegetation, so that the little creatures could choose according to their taste. These conditions are by no means impracticable, but how, in the large earthy ma.s.s, containing at least a cubic yard of soil, should we recover the atoms I had so much trouble to find in a handful of black soil from the heath? Moreover, such a laborious search would certainly detach the larva from its root.

The early subterranean life of the Cigale escapes us. That of the maturer larva is no better known. Nothing is more common, while digging in the fields to any depth, to find these impetuous excavators under the spade; but to surprise them fixed upon the roots which incontestably nourish them is quite another matter. The disturbance of the soil warns the larva of danger. It withdraws its proboscis in order to retreat along its galleries, and when the spade uncovers it has ceased to feed.

If the hazards of field-work, with its inevitable disturbance of the larvae, cannot teach us anything of their subterranean habits, we can at least learn something of the duration of the larval stage. Some obliging farmers, who were making some deep excavations in March, were good enough to collect for me all the larvae, large and small, unearthed in the course of their labour. The total collection amounted to several hundreds. They were divided, by very clearly marked differences of size, into three categories: the large larvae, with rudiments of wings, such as those larvae caught upon leaving the earth possess; the medium-sized, and the small. Each of these stages must correspond to a different age. To these we may add the larvae produced by the last hatching of eggs, creatures too minute to be noticed by my rustic helpers, and we obtain four years as the probable term of the larvae underground.

The length of their aerial existence is more easily computed. I hear the first Cigales about the summer solstice. A month later the orchestra has attained its full power. A very few late singers execute their feeble solos until the middle of September. This is the end of the concert. As all the larvae do not issue from the ground at the same time, it is evident that the singers of September are not contemporary with those that began to sing at the solstice. Taking the average between these two dates, we get five weeks as the probable duration of the Cigales' life on earth.

Four years of hard labour underground, and a month of feasting in the sun; such is the life of the Cigale. Do not let us again reproach the adult insect with his triumphant delirium. For four years, in the darkness he has worn a dirty parchment overall; for four years he has mined the soil with his talons, and now the mud-stained sapper is suddenly clad in the finest raiment, and provided with wings that rival the bird's; moreover, he is drunken with heat and flooded with light, the supreme terrestrial joy. His cymbals will never suffice to celebrate such felicity, so well earned although so ephemeral.

CHAPTER V

THE MANTIS.--THE CHASE

There is another creature of the Midi which is quite as curious and interesting as the Cigale, but much less famous, as it is voiceless. If Providence had provided it with cymbals, which are a prime element of popularity, it would soon have eclipsed the renown of the celebrated singer, so strange is its shape, and so peculiar its manners. It is called by the Provencals _lou Prego-Dieu_, the creature which prays to G.o.d. Its official name is the Praying Mantis (_Mantis religiosa_, Lin.).

For once the language of science and the vocabulary of the peasant agree. Both represent the Mantis as a priestess delivering oracles, or an ascetic in a mystic ecstasy. The comparison is a matter of antiquity.

The ancient Greeks called the insect [Greek: Mantis], the divine, the prophet. The worker in the fields is never slow in perceiving a.n.a.logies; he will always generously supplement the vagueness of the facts. He has seen, on the sun-burned herbage of the meadows, an insect of commanding appearance, drawn up in majestic att.i.tude. He has noticed its wide, delicate wings of green, trailing behind it like long linen veils; he has seen its fore-limbs, its arms, so to speak, raised towards to the sky in a gesture of invocation. This was enough: popular imagination has done the rest; so that since the period of cla.s.sical antiquity the bushes have been peopled with priestesses emitting oracles and nuns in prayer.

Good people, how very far astray your childlike simplicity has led you!

These att.i.tudes of prayer conceal the most atrocious habits; these supplicating arms are lethal weapons; these fingers tell no rosaries, but help to exterminate the unfortunate pa.s.ser-by. It is an exception that we should never look for in the vegetarian family of the Orthoptera, but the Mantis lives exclusively upon living prey. It is the tiger of the peaceful insect peoples; the ogre in ambush which demands a tribute of living flesh. If it only had sufficient strength its blood-thirsty appet.i.tes, and its horrible perfection of concealment would make it the terror of the countryside. The _Prego-Dieu_ would become a Satanic vampire.

Apart from its lethal weapon the Mantis has nothing about it to inspire apprehension. It does not lack a certain appearance of graciousness, with its slender body, its elegant waist-line, its tender green colouring, and its long gauzy wings. No ferocious jaws, opening like shears; on the contrary, a fine pointed muzzle which seems to be made for billing and cooing. Thanks to a flexible neck, set freely upon the thorax, the head can turn to right or left as on a pivot, bow, or raise itself high in the air. Alone among insects, the Mantis is able to direct its gaze; it inspects and examines; it has almost a physiognomy.

There is a very great contrast between the body as a whole, which has a perfectly peaceable aspect, and the murderous fore-limbs. The haunch of the fore-limb is unusually long and powerful. Its object is to throw forward the living trap which does not wait for the victim, but goes in search of it. The snare is embellished with a certain amount of ornamentation. On the inner face the base of the haunch is decorated with a pretty black spot relieved by smaller spots of white, and a few rows of fine pearly spots complete the ornamentation.

The thigh, still longer, like a flattened spindle, carries on the forward half of the lower face a double row of steely spines. The innermost row contains a dozen, alternately long and black and short and green. This alternation of unequal lengths makes the weapon more effectual for holding. The outer row is simpler, having only four teeth.

Finally, three needle-like spikes, the longest of all, rise behind the double series of spikes. In short, the thigh is a saw with two parallel edges, separated by a groove in which the foreleg lies when folded.

The foreleg, which is attached to the thigh by a very flexible articulation, is also a double-edged saw, but the teeth are smaller, more numerous, and closer than those of the thigh. It terminates in a strong hook, the point of which is as sharp as the finest needle: a hook which is fluted underneath and has a double blade like a pruning-knife.

A weapon admirably adapted for piercing and tearing, this hook has sometimes left me with visible remembrances. Caught in turn by the creature which I had just captured, and not having both hands free, I have often been obliged to get a second person to free me from my tenacious captive! To free oneself by violence without disengaging the firmly implanted talons would result in lacerations such as the thorns of a rosebush will produce. None of our insects is so inconvenient to handle. The Mantis digs its knife-blades into your flesh, pierces you with its needles, seizes you as in a vice, and renders self-defence almost impossible if, wis.h.i.+ng to take your quarry alive, you refrain from crus.h.i.+ng it out of existence.

When the Mantis is in repose its weapons are folded and pressed against the thorax, and are perfectly inoffensive in appearance. The insect is apparently praying. But let a victim come within reach, and the att.i.tude of prayer is promptly abandoned. Suddenly unfolded, the three long joints of the deadly fore-limbs shoot out their terminal talons, which strike the victim and drag it backwards between the two saw-blades of the thighs. The vice closes with a movement like that of the forearm upon the upper arm, and all is over; crickets, gra.s.shoppers, and even more powerful insects, once seized in this trap with its four rows of teeth, are lost irreparably. Their frantic struggles will never release the hold of this terrible engine of destruction.

The habits of the Mantis cannot be continuously studied in the freedom of the fields; the insect must be domesticated. There is no difficulty here; the Mantis is quite indifferent to imprisonment under gla.s.s, provided it is well fed. Offer it a tasty diet, feed it daily, and it will feel but little regret for its native thickets.

For cages I use a dozen large covers of wire gauze, such as are used in the larder to protect meat from the flies. Each rests upon a tray full of sand. A dry tuft of thyme and a flat stone on which the eggs may be laid later on complete the furnis.h.i.+ng of such a dwelling. These cages are placed in a row on the large table in my entomological laboratory, where the sun s.h.i.+nes on them during the greater part of the day. There I install my captives; some singly, some in groups.

It is in the latter half of August that I begin to meet with the adult insect on the faded herbage and the brambles at the roadside. The females, whose bellies are already swollen, are more numerous every day.

Their slender companions, on the other hand, are somewhat rare, and I often have some trouble in completing my couples; whose relations will finally be terminated by a tragic consummation. But we will reserve these amenities for a later time, and will consider the females first.

They are tremendous eaters, so that their entertainment, when it lasts for some months is not without difficulties. Their provisions must be renewed every day, for the greater part are disdainfully tasted and thrown aside. On its native bushes I trust the Mantis is more economical. Game is not too abundant, so that she doubtless devours her prey to the last atom; but in my cages it is always at hand. Often, after a few mouthfuls, the insect will drop the juicy morsel without displaying any further interest in it. Such is the ennui of captivity!

To provide them with a luxurious table I have to call in a.s.sistants. Two or three of the juvenile unemployed of my neighbourhood, bribed by slices of bread and jam or of melon, search morning and evening on the neighbouring lawns, where they fill their game-bags, little cases made from sections of reeds, with living gra.s.shoppers and crickets. On my own part, I make a daily tour of the paddock, net in hand, with the object of obtaining some choice dish for my guests.

These particular captures are destined to show me just how far the vigour and audacity of the Mantis will lead it. They include the large grey cricket (_Pachytylus cinerascens_, Fab.), which is larger than the creature which devours it; the white-faced Decticus, armed with powerful mandibles from which it is wise to guard one's fingers; the grotesque Truxalis, wearing a pyramidal mitre on its head; and the Ephippigera of the vineyards, which clashes its cymbals and carries a sabre at the end of its barrel-shaped abdomen. To this a.s.sortment of disobliging creatures let us add two horrors: the silky Epeirus, whose disc-shaped scalloped abdomen is as big as a s.h.i.+lling, and the crowned Epeirus, which is horribly hairy and corpulent.

I cannot doubt that the Mantis attacks such adversaries in a state of nature when I see it, under my wire-gauze covers, boldly give battle to whatever is placed before it. Lying in wait among the bushes it must profit by the prizes bestowed upon it by hazard, as in its cage it profits by the wealth of diet due to my generosity. The hunting of such big game as I offer, which is full of danger, must form part of the creature's usual life, though it may be only an occasional pastime, perhaps to the great regret of the Mantis.

Crickets of all kinds, b.u.t.terflies, bees, large flies of many species, and other insects of moderate size: such is the prey that we habitually find in the embrace of the murderous arms of the Mantis. But in my cages I have never known the audacious huntress to recoil before any other insect. Grey cricket, Decticus, Epeirus or Truxalis, sooner or later all are harpooned, held motionless between the saw-edges of the arms, and deliciously crunched at leisure. The process deserves a detailed description.

At the sight of a great cricket, which thoughtlessly approaches along the wire-work of the cover, the Mantis, shaken by a convulsive start, suddenly a.s.sumes a most terrifying posture. An electric shock would not produce a more immediate result. The transition is so sudden, the mimicry so threatening, that the unaccustomed observer will draw back his hand, as though at some unknown danger. Seasoned as I am, I myself must confess to being startled on occasions when my thoughts have been elsewhere. The creature spreads out like a fan actuated by a spring, or a fantastic Jack-in-the-box.

The wing-covers open, and are thrust obliquely aside; the wings spring to their full width, standing up like parallel screens of transparent gauze, forming a pyramidal prominence which dominates the back; the end of the abdomen curls upwards crosier-wise, then falls and unbends itself with a sort of swis.h.i.+ng noise, a _pouf! pouf!_ like the sound emitted by the feathers of a strutting turkey-c.o.c.k. One is reminded of the puffing of a startled adder.

Proudly straddling on its four hind-claws, the insect holds its long body almost vertical. The murderous fore-limbs, at first folded and pressed against one another on the thorax, open to their full extent, forming a cross with the body, and exhibiting the axillae ornamented with rows of pearls, and a black spot with a central point of white. These two eyes, faintly recalling those of the peac.o.c.k's tail, and the fine ebony embossments, are part of the blazonry of conflict, concealed upon ordinary occasions. Their jewels are only a.s.sumed when they make themselves terrible and superb for battle.