FEROCIOUS LARVÆ OF DRAGON-FLY.Page 120.
PART II.—THE LARVA.
CHAPTER I.
THE YOUNG LARVA.
The generality of insects, as has been before mentioned, are destined never to behold the birth of their progeny, nor to experience either the pleasures or the cares of parents surrounded by their families. Their anxieties cease when they have carefully stored up their eggs, and their existence is generally soon afterwards at an end. The insect world, therefore, presents us with but few opportunities of witnessing the display of a parental affection on the part of its members; but, as was mentioned in the conclusion of the last chapter, a few examples of the kind do exist,and, perhaps, the very fact of their being few in number contributes to make them the more interesting to us. We have seen a noble instance of self-devotion on the part of a poor spider in defence of her eggs. Let us now turn to some examples of the love of an insect mother for her young larva. If the reader will carefully search the twigs and leaves of the birch-tree in the month of July he may possibly succeed in finding the little insect, the field-bug, of which mention is about being made, and witness for himself the strange spectacle described in the following account from the great work on insects by De Geer. In order that it may be recognised, we have here adjoined a representation of the insect. Its colour is a greenish gray on the back, dotted all over with very minute black spots; the under portion of the insect is greenish yellow, with black spots. It lives upon the sap of the birch-tree.
The Field-bug.
The Field-bug.
"The mother," says De Geer, "was accompanied by a troop of little ones, sometimes as many as forty in number. She remained constantlywith them, generally on a twig or leaf. I noticed that the little ones and their mother did not always remain in the same place, and that as soon as the mother began to move to another position, all the little ones began to run after her, and stopped whenever the mother halted. She used to take them, as it were, for a walk from twig to twig, or from one leaf to another, parading up and down the branches of the tree, and she conducted them wherever she pleased, just as a hen does her chickens. It frequently afforded me great pleasure to observe their movements. One day I cut a young branch of the birch-tree inhabited by such an insect family, and I immediately saw the mother, apparently in great anxiety, begin to flap her wings violently, but without attempting to fly away, as though she would frighten away her enemy. At another time she would have immediately made her escape, thus plainly showing that she remained only in order to defend her young brood."
As if to furnish an instance of precisely the opposite import, the cruel and murderous father of this interesting little family is one of the greatest enemies the poor mother has to contend against.This hard-hearted parent does not hesitate whenever he falls in with one of his children to seize him and eat him up! If the mother spies him at this horrible feast she immediately attacks him in the manner described; and does her utmost to deter him from his cannibal propensities, by placing herself in an attitude of determined resistance before him. Was ever mother's love more plainly manifested than this love? No other instance of an affection so strange and strong is to be found in the tribe to which she belongs.
The care of the earwig not only extends to her eggs, but also to her young larvæ. "In the beginning of June," writes the author last quoted, "I found under a stone a female earwig, surrounded by a number of little creatures which I discovered to be her tiny family. She did not attempt to leave them, and they frequently ran and crouched under her, just as chickens under the wing of a hen. I took them up and placed them under a sand-glass, under which I had put a little fresh earth. They did not bore into the earth; and it was most curious to see them running for shelter under the mother, and pushing about between her feet, while she remained perfectlyquiet. I fed them with pieces of ripe apple, which the mother seized and ate with great avidity, detaching morsels of it by means of her teeth, and swallowing them. The young ones also ate a little of it, but with less avidity."
When the eggs of the spider mentioned in the last chapter as so devotedly attached to its treasure as to prefer death to parting with them, are hatched, they make their way out of the bag by an opening in it, being assisted by the mother in this difficult task. De Geer indeed states that this is the reason why the mother clings so tenaciously to the bag of eggs, as if she knew that her assistance in extricating her young from it was necessary. But this is not altogether correct, as they are able to make their way out by themselves in due time. When the young larvæ have come forth from the shell they run towards the mother, and climb upon her body; some get on her head, some on her back, and some on her limbs. In this manner she carries them about, and is said to feed them until they become strong enough to shift for themselves. "I have more than once been gratified," (writes one of the authors of the Introduction to Entomology,) "by a sight of this interesting spectacle;and when I nearly touched the mother, thus covered by hundreds of progeny, it was most amusing to see them all leap from her back, and run away in all directions."
For another instance of affection almost maternal for the young and helpless larvæ, let us take a peep into an ant's nest. So soon as ever the young larvæ emerge from the eggs they require the unremitting attention of the best and most careful nurses in order to rear them. They must be kept clean, fed, and taken for an airing as regularly as the day returns. By means of their tongues, which are incessantly used in licking them, their coats are kept of the most snowy white. They are fed three or four times a day by their nurses, who take care to masticate the food for them, and thus prepare it for their tender mouths. But the most strange part is their regularly being taken out for the benefit of the air and warmth. Some of the ants at the top of the nest watch for the first beams of the welcome sun, and, as soon as they pour upon the nest, they hasten down below in a great bustle to wake up the nurses, and bid them take the young ones out of their chambers and bring them up to the light, which these indefatigable antsquickly set about to do. After basking there all day long the nurses take care not to expose the delicate constitutions of the larvæ to the chill evening air; and soon as the sun begins to sink towards the horizon they carefully take them up and carry them to the warm deep cell below. For fear, perhaps, of their taking cold, they never allow them to be taken out in raw, damp, or frosty weather. It must not be forgotten, however, that these ants are not the parents of the larvæ; they are only the nurses.
But it becomes us now to pursue the more immediate subject of these remarks, and ask the reader's attention to a few particulars about thelarva. It is a great pity, for the sake of a clear perception of the facts of insect history, that there is a sad confusion of names in use among the majority of persons in speaking of the different forms and changes of insects. Who would imagine that caterpillar, grub, maggot, and larva, signified one and the same stage of the life of an insect? This abuse of terms cannot but render the knowledge of any science less easily retained than it would otherwise be, for the question is continually arising in the mind—If these all mean the same,why is not one term enough to express them? Let us then renounce those of uncertain meaning, and when we wish to give a name to the insect just emerged from its eggshell, let us call it by its proper name, theLarva.[C]
The larva, then, is the first form assumed by the insect on quitting its shell. No more a little inactive object lies before us, as in the egg and its slumbering tenant, but a sharp fellow, full of life, and soon walking off the field of the microscope, should we happen to be looking at it in that way, or from our book or table, should it be there placed by us for observation. By what hidden and mysterious power this has been effected who can tell? It was not heat alone that could animate the contents of the shell, nor could all a mother's care do more than preserve it from injury. It is very possible that chemistry hadsomeshare in it, and when the tiny being first awoke in the shell theoxygen of the air undoubtedly was necessary to its health, and the fulfilment of its early functions, but no more. Not chemistry, nor electricity, nor heat, nor any other known force could effect this wonderful change of apparently inanimate fluid into a lively, active, and well-organized being; much less could either of these give it its definite form, causing one larva to differ from another in its characters. No, we cannot tell how it has taken place, nor what has wrought the change; but we know the author of it—even Him who from the beginning created all things, and established those principles which, though hidden from our eyes, work out the marvels of the created world. It is enough for us to know and to remember this. Should we attempt more, we should probably fall under the Scripture reproof, "Professing themselves to be wise, they became fools."
Speaking generally, insects in the larva form appear as fleshy worms, having long and round bodies, marked with rings, and provided with a head and a certain number of legs, mostly six. How different in this condition, from the ballroom gaiety of the butterfly, or the elegant robesof the lace-wing flies. To look at a number of larvæ, all crawling over one another, and bearing perhaps not the most loving behaviour to each other as they scramble about, who would dream that, in a little while, those slowly moving bodies will be whirled through the air faster than our feet can pursue, or even than the eye can follow? Who also, but one well versed in the knowledge of insects, could venture to say what insect could be formed by this or that larva, now so little resembling winged insects at all?
Larvæ unlike the future Insects.
Larvæ unlike the future Insects.
Larvæ like the future Insects.
Larvæ like the future Insects.
In studying the forms and appearances of various larvæ, we shall find that some of them bear a tolerably close resemblance to the future insect; while others, on the contrary, do not resemble their future condition at all; and had we to decideto what tribe of insects they belonged, merely judging by their shape and character, we should be sorely perplexed to do so, and if we did, we should often in all probability be very far wrong. We need not go far for an illustration, first, of a larva like the perfect insect, and next, for one totally unlike it. Taking a candle and exploring into some snug hole near the kitchen fire-place, we shall not be long, probably, before we extricate a number of the larvæ of the cricket. Those of the bug also are very like the perfect insect; so also are young spiders, cockroaches and grasshoppers. These all resemble more or less perfectly the insect in its complete form.
Even amongst the larvæ not resembling the perfect insect, a little attention will enable us to perceive a sort of general resemblance between those of different genera and species, which we may call the Larva family likeness. This consists in the form of the body, in a number of instances; but in all in the ring-like marks or segments of the body, as they are called, which arethirteenin number. If the reader will take the trouble to count the rings in the larvæ of different insects, he will generally find that they are thirteen in number.The general resemblance of larvæ to one another may also be noticed. The larva is, in every instance, destitute of wings. In many cases, larvæ are provided with feet, in many others they have none. And in some instances, they have no distinct head, as in the larva of the blow fly.
By far the larger number of larvæ belong to this class; that is, they do not resemble the perfect insect. Do not resemble! could any one believe that these strange, and some of them awful looking larvæ everbecamebutterflies? yet they all belong to that tribe of insects.
In order to give a clear conception of the structure of a larva, we may briefly mention the names of its various parts. First then, there is aheadof various shapes, sometimes of the shape of a heart, sometimes round or triangular. Attached to the head are the twoantennæ; or, as they are commonly called,feelers, most probably an incorrect expression, as it appears that insects may possiblyhearas well as feel by their means. At the side of the head are theeyes, which are formed much more simply than those of the perfect insect. Next is themouth, provided with its upper and lower pair of jaws. Then there is thebodyand itslegs; and lastly, there is in many larvæ, living in the water, atail, which, strange to say, is provided with a delicate tube, through which the larva breathes. A beautiful instance of such an appendage to the body of the larva, is represented in the adjoining cut;the various parts of the larva are also represented in the accompanying figure.
Diagram of a Larva.
Diagram of a Larva.
We may now enter upon a few particulars connected with the general history of insects in the larva form.
CHAPTER II.
HABITS OF THE LARVA.
Generally, for a little while after the larva has emerged from the shell, it is in a very weak and languid condition. The effort of extricating itself from its little prison-house, seems to leave it almost without strength; and for a period which varies in different insects, it lies helpless and almost motionless at the mercy of any wandering adversary, and might be demolished without resistance. But this hour of weakness, except in a few cases, is not prolonged. In the course of an hour or two, or even much less in some instances, the larva revives, takes heart, and begins by eating whatever food may happen to lie in its way; and now the larva becomes a terror to the world of insects, or even, indirectly, to man and to nations. Instead of simply eating, in order to live, like most other beings, it only livesto eat; it has no other duty to perform at present but to eat as fast and as much as it possibly can in a certain time; and it must be confessed, the larva, generally speaking, leaves little to be desired on the score of a sharp appetite. Unlike other creatures who allow themselves a certain period between their meals, the larva sets to its feast and does not leave the table until it has devoured all its contents,—upon which it immediately begins again elsewhere. Nogourmandin the world, whether among human beings or brutes, can compare with the insect in this form for the amount of food consumed. Morning, noon, and night, is to it only a continued round of feasting; and, as may well be imagined, the larva grows very rapidly accordingly. Some larvæ consume animal, others vegetable food; or, in the language of science, some arecarnivorous, some aregraminivorousorherbivorous, and some will eat anything almost that comes before them—these would be called, and very appropriately so,omnivorous.
Let us speak of carnivorous larvæ first. The larvæ which have carnivorous propensities render themselves often truly terrible to the insect world around them. The most mighty warrior that everlived in his whole career never slew half so many of his own species as the larva of a beautiful fly does ofaphidesin a few hours. Well does Réaumur call them the "lions of the aphides," and thus does he describe their method of proceeding:—
Lion of the Aphides.
"There is no beast of prey in nature who hunts so entirely at his ease as does this larva. Resting upon a twig or a leaf, he is surrounded on every side by the insects on which he feeds; often, indeed, they touch his sides, and he is able to catch hundreds of them without changing his position. Not only do the poor little aphides not fly from him, but they may be often seen creeping over the body of their enemy. It is only after the larva has eaten up the greater number of his prey around him, that he has any need to remove to a spot as thickly inhabited by them as that in which he has been making his cruel ravages. In order to observe the manner in which he attacks them, the best plan is to take him, put him between two leaves, and shut him up in a box for ten or twelve hours to sharpen his appetite. After this fast he must be placed on some spot where the aphides are found in abundance. Immediately he begins exploring around for prey, which he doessimply by the sense of touch, as he does not appear to be able to see. At length an unhappy insect comes within his reach. Brandishing a trident with which he is armed, he immediately transfixes the insect, just as we take up a morsel of food upon a fork!" The little creature is then sucked into a sort of cavity like the neck of a bottle, where it is retained by a couple of pins until its juices are emptied by the destroyer, when he casts it away, now nothing more of it being left but a dry, shrivelled, empty skin. The aphis-lion, however, loses no time, and presently seizes another, which he pierces and sucks dry as quickly as the last.[D]When very hungry he will devour one a minute. Réaumur says, "I have seen him eat twenty of these insects one afteranother in twenty minutes; nor did this satisfy him: for in the course of two hours he devoured more than a hundred insects with which I supplied him!" These larvæ do repose a little, but never for long, for they are seldom without some prey in hand. "I have seen," adds the last author, "twigs of the elder seven or eight inches in length entirely covered with these insects, (theaphides,) and in four days' time there remained not one alive."
This larva is a rare specimen of courage, as well as of destructive powers; for when it is quite young it often seizes upon an insect twice as big as itself. It is very amusing to see the unequal contest between the little but courageous foe, and his great, bulky, and stupid adversary. Immediately the larva thrusts its trident into the body of the enemy, who, stupid as he is, does not like the sensation of the wound in his side, and makes off as fast as he can. The lion-hearted larva follows him up and wrestles with him, and at length actually boards him, to use a sailor's term, clambering up his sides, and, in triumph, piercing him through and slaying him. What is perhaps most singular of all, the larvæ of some species of theseflies not only slay their victims, but actually clothe themselves, after the manner of Hercules on his victory over the Nemæan lion, with the skins of their prey!
It is almost to be regretted that the insect world has not had the privilege of having its combats sung by the poets. Who can forget the animated scenes, painted in such life-like colours by Homer and Virgil, of the conflicts, hand to hand, of the heroes of their verse? But the history of insects supplies us with more singular and more interesting deeds of fight than have ever yet been fabled by poets, or commemorated in song. In the instance we are about to quote, the larva of the ant-lion is the crafty Giant Grim, who lives by entrapping, as we have before said, poor wayfaring travellers. Like those giants of old, of whom we read in books a little more wonderful than true, this subtle and powerful enemy lies deeply ensconced in his subterraneous cavern, patiently abiding the time when his unsuspecting prey shall fall into his power. His trap is depicted on the opposite page.
An Ant-lion in its Trap.
This insect is naturally a very helpless being, it can only walk at a slow pace, and strange to add, it can only walk backwards, and not forwards!Yet its food is the juice of insect bodies. How, then, is it to seize upon them circumstanced so unfavourably as it is, having neither swiftness nor ability to direct its motions sufficiently actively to fit it for such a task? It succeeds by an artifice of the most refined character. Nothing daunted by what we might call its natural disadvantages, the insect sets bravely to work to construct a trap for its prey; and the manner in which this is performed may well strike us with wonder, and raise our admiration up to Him who has so marvellously endowed this humble being with wisdom and skill. It first takes care to choose out a proper site forthe work it is about, and in this always selects a soil composed of fine, loose, and dry sand, well aware that, as we shall presently see, no other would be fit for its purpose. Generally it chooses such a soil under the shelter of an old wall, where the rain cannot easily penetrate and ruin its work. In so doing it shows its wisdom; for thither, when the heat of the sun is great, or when the rain-drops fall heavily, crowds of insects come for shelter, and fall into its cruel embrace.
Circular Ditch of the Ant-lion.
The site being chosen, the next important step is to mark out the bounds of its habitation, and with this view the insect begins digging a circular ditch, walking backwards until it has completed the circle. This defines the outer limits of its trap, and is a sort of guide line to it in its future operations. Then it sets about the more proper task of excavating its trap. Would that our readers could see this insect at work! Of all the wonderfulsights presented to us in the insect world there is none to equal it in interest, none so calculated to enlist our sympathies on the part of the patient, skilful, and unwearied little labourers of this kingdom of nature. Guided by the line it has marked out, the workman steps into the circle, and sets to work with a hearty good will, and with a degree of diligence and excavating skill that would put our railroad "navigators" to the blush. Shower after shower of sand is seen flying up and beyond the boundary described, with the most unintermitting diligence, until the insect has completed the circle again; arrived there, it turns round and excavates back again until it arrives at the same point. But it may perhaps be asked, where are its tools, and by what means does it succeed in casting up these loads of earth? We fear that at best any written description will hardly do justice to our ingenious labourer; its method, however, is as follows:—It uses the head as the spade, or rather shovel, and in the strangest manner it fills the shovel with one of its feet with a load of sand, and then by a quick movement of the head tosses it out of the cavity. By working in alternate directions it manages so as never toover-fatigue one leg, for on its return the leg previously in use is at rest, while the one on the opposite side is now called into duty. The insect thus works on until its trap is completely excavated, the task occupying a variable time; sometimes being finished in half an hour, sometimes even in less, but occasionally occupying several hours, the little labourer being obliged to rest a certain time. Réaumur, who has given a fascinating account of these insects, writes, "I have had at times hundreds of ant-lions in a large box, and I have often been amused with filling up their traps. Some of them would immediately begin to form another; but the greater number in the warm long days of summer deferred executing the work until the sun began to go down. They seldom worked in the heat of the day; but in cold or cloudy weather they would excavate at any hour."
We well know what perplexity a chain of rocky hills causes to a railroad engineer, and what vast outlays of money, labour, and time are necessary in order to overcome the obstacle thus presented to the path of the engine and its train. But it may be safely said that we can furnish a parallel instanceof difficulty and of patient, all-surmounting exertion from the history of the insect before us. M. Bonnet was curious to know what it would do if a stone or some such obstacle were met with in the process of its excavations, and one day had the gratification of observing the behaviour of the insect under these trying circumstances. Not being able to cast it out with its head, the insect determined to carry it out, if possible, on its back. With this view it contrived by various manœuvres to place the stone upon its back and to balance it there. This was the least difficult part of the undertaking. The insect had to climb up an inclined plane upon soil, chosen with other views purposely by itself, as shifting and unsteady as possible, and not only so, but to preserve the balance of the stone with which it was encumbered. Undaunted by these difficulties it made the attempt, but the first step brought down a shower of sand, and tumbled the little rock to the bottom. Again and again did the heroic insect attempt the same feat, and with the same ill success, and we might have thought we beheld a realization of the fable of Sisyphus and the rolling-stone, in the vain endeavours of the insect to get rid of its encumbrance. Five or sixtimes did the insect repeat its endeavours, and at last, after one or two narrow escapes, the stone was fairly lodged on the outside of the trap, and the insect returned to its subterraneous recess at the bottom of the cell in triumph.
The traps vary in size in proportion to the age of the insects which construct them. The young insects only form very small ones; but as even from the moment of their birth they are destined to toil for their food, they do not wait in idleness and hunger because they cannot make large efforts, but are content to make little traps not more than a few parts of an inch in diameter. Thus they set us the needful example of not despising to do small things because our strength is not yet equal to the performance of as much as we could desire. The diameter of the trap formed by a full-grown insect is about three inches; the depth about two.
When its labours are over, it has been well remarked, the insect now only requires patience—but it must have a good deal of it! It generally buries itself, all but its jaws, in the sand at the bottom, and here awaits its victims. If it requires much patience, surely it also needs to have much powerof endurance of hunger, for it may wait for days sometimes without catching any prey. Frequently, when this is the case, it marches out of its trap, and tries its fortune in some more favourable spot. But see! an ant who has been out foraging for the young ants at home is hastening back laden with sweet treasures, when suddenly she finds her path arrested by what appears to her to be a deep but smooth precipice. To plunge down and rise on the opposite side is a shorter cut, in her estimation, than to go round; or perhaps she is led by curiosity to wish to explore this singular cavity, and she plants her feet on its treacherous edge, causing a few grains of sand to roll down and give notice to the wary giant below that a victim is at hand. A step back, and her life would be saved; but no, she leaves the bank, trusts herself to the unfaithful soil of the sides of the precipice, and instantly rolls down in a cloud of dust to the bottom. Terror has now laid hold of her, and with all speed she strives to clamber up the unsteady sides. For a moment escape appears possible, but the Argus-eyed monster below starts up into activity, and piling upon his head a huge load of sand, he shoots it after the escaping ant, and once more brings herdown covered with dust into his embrace. The terrible jaws are instantly closed upon the unhappy insect, and in a few minutes her existence is at an end, the savage enemy shaking her violently, or dashing her quivering frame against the earth.
Singular to add, the ant-lion loves not dead prey, and will indignantly cast it out of its trap. Says Réaumur, "They appear so much to delight in the glory of a victory, that they disdain to touch an insect who is not, to say the least, in a condition to contend with them!" It certainly is not that the food when offered to it dead is not fresh enough that it is thus treated; for if only killed an instant before the insect still refuses to touch it. Réaumur is disposed to believe that, like our sportsmen, these interesting but cruel insects destroy prey more for the pleasure of exhibiting their superior skill, than to appease their hunger. But it is rather uncharitable even to the ant-lion, to say so much as this. When the insect has sucked all the juices out of its victim's body, it casts it out of its trap, and the earth around, strewed with dead bodies, is thus the silent witness to the destroying powers of the giant within.
This singular insect, whose exploits have detained us so long, remains in its larva form two years, growing daily in size until it has completed its existence as a larva, and must then enter upon another condition of life. It is to be regretted that it is not to be found in England, or at least it has not been for some time discovered in our island; but it is common in France and other parts of the continent, and would well repay the trouble of being brought over. As the insect is very patient of hunger, it might easily be conveyed in a little wooden box, half filled with fine sand, and its proceedings could be readily watched by placing it under a bell-glass, or in a little glass case, introducing a few ants or spiders for its food from time to time.
The insect exhibits to us a wonderful instance of what we may call, after the example of Dr. Paley, the principle of compensation in nature. It can neither run nor fly with the speed necessary to overtake its prey who are swifter of foot than itself. But God never created it to starve, and has endowed it with a rare combination of faculties by which it is enabled to live in the midst of plenty if not even of luxuriance.So it is in a thousand other cases in nature. So it is indeed in Providence likewise. If He sends us trials, "He also makes a way to escape that we may be able to bear them." If our day is to be dark and cloudy, and to call for the exercise of much faith and patience, there is still the same provision made; "as thy day so shall thy strength be." If our lot in life is one of hardship He can, and if it is sought of him aright He will, and He does bear us up, revive our drooping strength, and enable us to go on our way rejoicing.
Cells of Sand-Wasp.
Let us go on to speak now of some other carnivorous larva. If in the month of July we can find out a spot where we can detect the traces of the labours of the sand-wasp, of whom mention has been made at page 15, and cutting out a little mass of the sand-rock containing several of their burrows, then take the trouble to open gently one of the cells formed by these insects, we shall see a carnivorous larva in as happy a condition as a fox in a hen-roost, or a mouse in the midst of a cheese! The best way to obtain access to this securely imbedded and luxurious larva, is to moisten the mass of sand with a little water, and then slice it gently down with an old knife until we come tothe cells. They are here represented. At the bottom of each we shall see the larvæ which have sprung from the eggs deposited in the manner before described, after the arduous and affectionate labours of the parent. Then above each is a heap of caterpillars, arranged with beautiful neatness, and larvæ and caterpillars are both fast locked in their prison house by the firm stopping with which the parent wasp has closed the mouth of the cells. These caterpillars are all alive, and are rolled into a ring-like form, but are so chained down that they cannot move in the least degree. The poor prisoners, like the sheep in the slaughter-yard, are only waiting their turn to be killed and devoured. The larva soon after it is hatched finds himself in the midst of a well-stored larder, and has nothingto do but eat, which he does not long delay doing. He devours at his ease, and revels in the dainty fresh food which the care of his parent had laid up. When he has eaten all his prisoners up, and grown to his full size, he lays down to sleep, to awake again in another and a far different form.
Larva of Wood-boring Wasps.
Sometimes the reader may have the opportunity, it may be, of finding out the nest of the wood-boring wasp, and he may in June or July, perhaps, succeed in discovering another instance of a larva in a happy state of plenty. The larva is sure to be found at the bottom, and above it will be piled a heap of insects for its food. What is remarkable about this store of food is, that the insects thus made prisoners are not dead, for they would, if so, soon become corrupted, and unfit for the diet of the larva; they are in a sort of half stupified condition,in all probability very like that induced by the late plan of breathing ether and other vapours to render persons insensible to pain, while surgically operated on. Since this plan has been introduced, we read in some of the newspapers—we may question with what truth—that the butchers in Albany (America,) give ether to the oxen before killing them, so as to make them insensible to the pain of the death-blow! But the wasps in question have for ages been in the habit of effecting the same end by stinging their captives, the poison not sufficing to kill them, nor yet permitting them to be actively alive.
The insects thus stored up for the larva cost the parent many a conflict in their capture. And here we may interest the reader by describing the exploits of a warrior wasp, abundant in the Isle of France. It is curious that in the Isle of France the common bee is not to be found as a native of the woods, while, in the Isle of Bourbon, it is very common, and furnishes an abundance of wax and honey. This is explained by supposing that the warriors of whom we are about to speak destroy the bees, and have thus prevented their multiplying in the island in question. Truly, like thebanditti of whom we read in books, these wasps are splendidly attired, although not in the spoils of those they have robbed. Their head, chest, and body is of a resplendent lustre; now green, or, seen in another position, blue, and glistening with all the lustre of an exquisite varnish; their antennæ are black, their eyes of a brownish yellow, and their legs partly bronze-coloured, and partly of a beautiful violet. They are strong and swift of wing, and are possessed of a terrible lance, the thrusts of which even man cannot endure without far more pain and inflammation than attends an ordinary sting.
The foe with whom these magnificently-dressed warriors have to contend, is a kind of insect allied to the cockroach, which, in our kitchens, has acquired the incorrect title of "black beetle." This insect is detested by the inhabitants of the island, for its ravages upon almost everything of value or delicacy, and is not less hated by the sailor for its destructiveness on ship-board. It is calledKakerlac, and is much larger than the cockroaches, which are the plague and terror of our cooks. Imagine that one of these great and odious insects is marching along the highway.The warrior wasp has also been making his expeditions for prey abroad, when suddenly his eager eye catches sight of the kakerlac hastening to some new scene of depredation. The warrior instantly alights, and the kakerlac stops, thinking perhaps to intimidate its adversary by its size and ferocious aspect. Both insects glare at one another;—
——"each other from afarThey view, and rushing on, begin the war.They launch their spears; then hand to hand they meet,The trembling soil resounds beneath their feet;Their bucklers clash, thick blows descend from high,And flashes of fire from their hard helmets fly.Courage conspires with chance, and both engageWith equal fortune yet, and mutual rage."
——"each other from afarThey view, and rushing on, begin the war.They launch their spears; then hand to hand they meet,The trembling soil resounds beneath their feet;Their bucklers clash, thick blows descend from high,And flashes of fire from their hard helmets fly.Courage conspires with chance, and both engageWith equal fortune yet, and mutual rage."
Virgil's description, though scarcely accurate in all points, gives us a lively image of this insect combat. The kakerlac, however, is the Turnus, and the warrior wasp the Æneas of the fight. The wasp is the first to attack, and darts upon the other, seizing it by the muzzle with its strong jaws, then bending its body so as to bring its tail under the abdomen of the kakerlac, the lance with its charge of poison is deep-plunged into the body of the unhappy foe, imbuing a deadly venom into its system. Having made this thrust, thewarrior looses the foe, and soars in triumph a little way into the air, satisfied of a successful issue.
The wretched kakerlac, after a few brief convulsions, lies paralysed on the ground unable to stir a step from the spot where it encountered its terrible adversary. Fully aware of this, the victorious wasp, after taking a few turns, as if to proclaim the downfall of the Giant Kakerlac to the surrounding neighbourhood, returns to the scene where the conflict was fought. The kakerlac, unable to resist the victor, and being naturally, though a great devourer, a very faint-hearted creature, lies immovable while the wasp seizes the prostrate foe by the head, and in a sort of triumphal march drags it along the road to its nest. But though the kakerlac was not a difficult enemy to overcome, the weight and size of its body are a sore burden to the victor wasp. The way to the nest is long, tedious, and rugged. After a hard pull over all sorts of obstacles the wasp becomes completely breathless, and is obliged to let go, and for a rest it generally rises into the air, probably with a view of reconnoitring future difficulties, and of ascertaining the bestroute to pursue. Thus, after alternately dragging along the body of its victim and rising up to spy out the path, at length the conqueror succeeds in bringing the carcase home.
Here, however, arises another difficulty. To attempt to get the body of the huge kakerlac in, is just as if one were to attempt to get an elephant through a small street-door. What is to be done? The wasp enters the hole backwards, and, seizing the head of the kakerlac, endeavours with all its might to drag it in, but all in vain. Many times it repeats these efforts with the same want of success; and now it appears that its labours in bringing hither the corpse, and its dangers in the battle, were all for nought, for the great body cannot be put in the place the wasp had designed for it. As if exasperated with the difficulties, out comes the wasp in fury, and falling upon the body of the kakerlac, hews off the large wing-cases, together with several of the limbs, and goes back into the hole again to repeat the attempt to get it in. Success at length crowns its efforts; by little and little the body becomes lost to sight, and finally disappears altogether from view, being carried down to the very bottomof the nest. Here the larva, as soon as hatched, feeds upon it, thrives, and grows, and falls asleep, awaiting the time when itself shall awake to follow in the steps of the glittering and formidable warrior who, with the boldness of an amazon and affection of the tenderest of mothers, supplied it with nourishment during its hours of infancy.
This may be thought a scene of sad carnage, but the following will, perhaps, appear even more so. What should we say, if deep in the forests of some wild uncultivated country was found a den, the bottom of which was strewed with skulls, with bones, and mangled limbs? What fearful scenes should we not suspect to have taken place in this dark and horrid place; and as we shuddered in looking round upon its walls, as the once witnesses of terrible deeds, we might even fancy we heard the cry of the poor traveller, whose last agonies were seen by no eye but that of the monster who had waylaid and murdered him? Such a den may be found in the forest, made horrible by the cut-off heads, limbs, and wings of insects—it is the habitation of the carnivorous larva of a wasp. Nay more, as is seen in the engraving, the insect monster actually works up the cut-off wings and limbs intoa sort of covering for itself, and finally buries itself in a shroud partly made of the spoils of former victims.
The Larva of a Wasp in its coat of wings and limbs.
Perhaps the carnivorous larva of the tiger-beetle, orcicindela, is as ferocious a being as any in this state. In this respect, indeed, it resembles the perfect insect, whose title sufficiently indicates its swiftness, cunning, and blood-thirsty nature. "These larvæ," writes Mr. Westwood, "burrow cylindric retreats in the earth, to the depth of a foot or more, employing their legs and jaws in loosening the particles of sand and earth, which they carry to the surface upon their broad, saucer-like head, ascending by the assistance of the two hooks upon the back, somewhat after the fashion of a sweep going up a chimney! Having completed this burrow, they station themselves, by means of their legs and back hooks, at its mouth, their large flattened head and great segment filling the hole." Here they remain all day long, and many an insect might pass close by, little dreaming of the terrible foe who lay under that trap-door. Presently comes a spider scrambling over the ground in haste to mount up a branchon which to hang one of its web lines; the treacherous trap-door is in its direct path. Its feet rest on it; instantly the trap drops, and the poor insect falls into the dark den, and is caught in the powerful jaws of the artful larva. Truly, there is something even to man a little intimidating in the sight of such a monster as is represented here; how much more to the unfortunate insect who happens to be caught in its embrace, and having only time to just catch a glimpse of its fearful captor, is dragged down in a cloud of dust to be devoured in darkness at the bottom of the den. Yet this also, like other cruel creatures, is in reality a very timid larva, and instantly on the approach of danger, drops to the bottom of the cell, where, if we have courage to pursue it, we shall find it much in the attitude in which it is here represented. The singular pair of hooks on its back are used as the flukes of an anchor to sustain the insect in the position it assumes at the mouth of the cell.