Social Life in the Insect World Part 13

One thing I do see more clearly after all my experiments and research: the tactics of the Philanthus. As a witness of its ferocious feasting, the true motive of which was unknown to me, I treated it to all the unfavourable epithets I could think of; called it a.s.sa.s.sin, bandit, pirate, robber of the dead. Ignorance is always abusive; the man who does not know is full of violent affirmations and malign interpretations. Undeceived by the facts, I hasten to apologise and express my esteem for the Philanthus. In emptying the stomach of the bee the mother is performing the most praiseworthy of all duties; she is guarding her family against poison. If she sometimes kills on her own account and abandons the body after exhausting it of honey, I dare not call her action a crime. When the habit has once been formed of emptying the bee's crop for the best of motives, the temptation is great to do so with no other excuse than hunger. Moreover--who can say?--perhaps there is always some afterthought that the larvae might profit by the sacrifice. Although not carried into effect the intention excuses the act.

I therefore withdraw my abusive epithets in order to express my admiration of the creature's maternal logic. Honey would be harmful to the grubs. How does the mother know that honey, in which she herself delights, is noxious to her young? To this question our knowledge has no reply. But honey, as we have seen, would endanger the lives of the grubs. The bees must therefore be emptied of honey before they are fed to them. The process must be effected without wounding the victim, for the larva must receive the latter fresh and moist; and this would be impracticable if the insect were paralysed on account of the natural resistance of the organs. The bee must therefore be killed outright instead of being paralysed, otherwise the honey could not be removed.

Instantaneous death can be a.s.sured only by a lesion of the primordial centre of life. The sting must therefore pierce the cervical ganglions; the centre of innervation upon which the rest of the organism is dependent. This can only be reached in one way: through the neck. Here it is that the sting will be inserted; and here it is inserted in a breach in the armour no larger than a pin's head. Suppress a single link of this closely knit chain, and the Philanthus reared upon the flesh of bees becomes an impossibility.

That honey is fatal to larvae is a fact pregnant with consequences.

Various predatory insects feed their young with honey-makers. Such, to my knowledge, are the _Philanthus coronatus_, Fabr., which stores its burrows with the large Halictus; the _Philanthus raptor_, Lep., which chases all the smaller Halictus indifferently, being itself a small insect; the _Cerceris ornata_, Fabr., which also kills Halictus; and the _Polaris flavipes_, Fabr., which by a strange eclecticism fills its cells with specimens of most of the Hymenoptera which are not beyond its powers. What do these four huntresses, and others of similar habits, do with their victims when the crops of the latter are full of honey? They must follow the example of the Philanthus or their offspring would perish; they must squeeze and manipulate the dead bee until it yields up its honey. Everything goes to prove as much; but for the actual observation of what would be a notable proof of my theory I must trust to the future.

CHAPTER XIV

THE GREAT PEAc.o.c.k, OR EMPEROR MOTH

It was a memorable night! I will name it the Night of the Great Peac.o.c.k.

Who does not know this superb moth, the largest of all our European b.u.t.terflies[3] with its livery of chestnut velvet and its collar of white fur? The greys and browns of the wings are crossed by a paler zig-zag, and bordered with smoky white; and in the centre of each wing is a round spot, a great eye with a black pupil and variegated iris, resolving into concentric arcs of black, white, chestnut, and purplish red.

Not less remarkable is the caterpillar. Its colour is a vague yellow. On the summit of thinly sown tubercles crowned with a palisade of black hairs are set pearls of a turquoise-blue. The burly brown coc.o.o.n, which is notable for its curious tunnel of exit, like an eel-pot, is always found at the base of an old almond-tree, adhering to the bark. The foliage of the same tree nourishes the caterpillar.

On the morning of the 6th of May a female emerged from her coc.o.o.n in my presence on my laboratory table. I cloistered her immediately, all damp with the moisture of metamorphosis, in a cover of wire gauze. I had no particular intentions regarding her; I imprisoned her from mere habit; the habit of an observer always on the alert for what may happen.

I was richly rewarded. About nine o'clock that evening, when the household was going to bed, there was a sudden hubbub in the room next to mine. Little Paul, half undressed, was rus.h.i.+ng to and fro, running, jumping, stamping, and overturning the chairs as if possessed. I heard him call me. "Come quick!" he shrieked; "come and see these b.u.t.terflies!

Big as birds! The room's full of them!"

I ran. There was that which justified the child's enthusiasm and his hardly hyperbolical exclamation. It was an invasion of giant b.u.t.terflies; an invasion hitherto unexampled in our house. Four were already caught and placed in a bird-cage. Others--numbers of them--were flying across the ceiling.

This astonis.h.i.+ng sight recalled the prisoner of the morning to my mind.

"Put on your togs, kiddy!" I told my son; "put down your cage, and come with me. We shall see something worth seeing."

We had to go downstairs to reach my study, which occupies the right wing of the house. In the kitchen we met the servant; she too was bewildered by the state of affairs. She was pursuing the huge b.u.t.terflies with her ap.r.o.n, having taken them at first for bats.

It seemed as though the Great Peac.o.c.k had taken possession of my whole house, more or less. What would it be upstairs, where the prisoner was, the cause of this invasion? Happily one of the two study windows had been left ajar; the road was open.

[Ill.u.s.tration: THE GREAT PEAc.o.c.k OR EMPEROR MOTH.]

Candle in hand, we entered the room. What we saw is unforgettable. With a soft _flic-flac_ the great night-moths were flying round the wire-gauze cover, alighting, taking flight, returning, mounting to the ceiling, re-descending. They rushed at the candle and extinguished it with a flap of the wing; they fluttered on our shoulders, clung to our clothing, grazed our faces. My study had become a cave of a necromancer, the darkness alive with creatures of the night! Little Paul, to rea.s.sure himself, held my hand much tighter than usual.

How many were there? About twenty. To these add those which had strayed into the kitchen, the nursery, and other rooms in the house, and the total must have been nearly forty. It was a memorable sight--the Night of the Great Peac.o.c.k! Come from all points of the compa.s.s, warned I know not how, here were forty lovers eager to do homage to the maiden princess that morning born in the sacred precincts of my study.

For the time being I troubled the swarm of pretenders no further. The flame of the candle endangered the visitors; they threw themselves into it stupidly and singed themselves slightly. On the morrow we could resume our study of them, and make certain carefully devised experiments.

To clear the ground a little for what is to follow, let me speak of what was repeated every night during the eight nights my observations lasted.

Every night, when it was quite dark, between eight and ten o'clock, the b.u.t.terflies arrived one by one. The weather was stormy; the sky heavily clouded; the darkness was so profound that out of doors, in the garden and away from the trees, one could scarcely see one's hand before one's face.

In addition to such darkness as this there were certain difficulties of access. The house is hidden by great plane-trees; an alley densely bordered with lilacs and rose-trees make a kind of outer vestibule to the entrance; it is protected from the _mistral_ by groups of pines and screens of cypress. A thicket of evergreen shrubs forms a rampart at a few paces from the door. It was across this maze of leaf.a.ge, and in absolute darkness, that the b.u.t.terflies had to find their way in order to attain the end of their pilgrimage.

Under such conditions the screech-owl would not dare to forsake its hollow in the olive-tree. The b.u.t.terfly, better endowed with its faceted eyes than the owl with its single pupils, goes forward without hesitation, and threads the obstacles without contact. So well it directs its tortuous flight that, in spite of all the obstacles to be evaded, it arrives in a state of perfect freshness, its great wings intact, without the slightest flaw. The darkness is light enough for the b.u.t.terfly.

Even if we suppose it to be sensitive to rays unknown to the ordinary retina, this extraordinary sight could not be the sense that warns the b.u.t.terfly at a distance and brings it hastening to the bride. Distance and the objects interposed make the suggestion absurd.

Moreover, apart from illusory refractions, of which there is no question here, the indications of light are precise; one goes straight to the object seen. But the b.u.t.terfly was sometimes mistaken: not in the general direction, but concerning the precise position of the attractive object. I have mentioned that the nursery on the other side of the house to my study, which was the actual goal of the visitors, was full of b.u.t.terflies before a light was taken into it. These were certainly incorrectly informed. In the kitchen there was the same crowd of seekers gone astray; but there the light of a lamp, an irresistible attraction to nocturnal insects, might have diverted the pilgrims.

Let us consider only such areas as were in darkness. There the pilgrims were numerous. I found them almost everywhere in the neighbourhood of their goal. When the captive was in my study the b.u.t.terflies did not all enter by the open window, the direct and easy way, the captive being only a few yards from the window. Several penetrated the house downstairs, wandered through the hall, and reached the staircase, which was barred at the top by a closed door.

These data show us that the visitors to the wedding-feast did not go straight to their goal as they would have done were they attracted by any kind of luminous radiations, whether known or unknown to our physical science. Something other than radiant energy warned them at a distance, led them to the neighbourhood of the precise spot, and left the final discovery to be made after a vague and hesitating search. The senses of hearing and smell warn us very much in this way; they are not precise guides when we try to determine exactly the point of origin of a sound or smell.

What sense is it that informs this great b.u.t.terfly of the whereabouts of his mate, and leads him wandering through the night? What organ does this sense affect? One suspects the antennae; in the male b.u.t.terfly they actually seem to be sounding, interrogating empty s.p.a.ce with their long feathery plumes. Are these splendid plumes merely items of finery, or do they really play a part in the perception of the effluvia which guide the lover? It seemed easy, on the occasion I spoke of, to devise a conclusive experiment.

On the morrow of the invasion I found in my study eight of my nocturnal visitors. They were perched, motionless, upon the cross-mouldings of the second window, which had remained closed. The others, having concluded their ballet by about ten o'clock at night, had left as they had entered, by the other window, which was left open night and day. These eight persevering lovers were just what I required for my experiment.

With a sharp pair of scissors, and without otherwise touching the b.u.t.terflies, I cut off their antennae near the base. The victims barely noticed the operation. None moved; there was scarcely a flutter of the wings. Their condition was excellent; the wound did not seem to be in the least serious. They were not perturbed by physical suffering, and would therefore be all the better adapted to my designs. They pa.s.sed the rest of the day in placid immobility on the cross-bars of the window.

A few other arrangements were still to be made. In particular it was necessary to change the scene; not to leave the female under the eyes of the mutilated b.u.t.terflies at the moment of resuming their nocturnal flight; the difficulty of the search must not be lessened. I therefore removed the cage and its captive, and placed it under a porch on the other side of the house, at a distance of some fifty paces from my study.

At nightfall I went for a last time to inspect my eight victims. Six had left by the open window; two still remained, but they had fallen on the floor, and no longer had the strength to recover themselves if turned over on their backs. They were exhausted, dying. Do not accuse my surgery, however. Such early decease was observed repeatedly, with no intervention on my part.

Six, in better condition, had departed. Would they return to the call that attracted them the night before? Deprived of their antennae, would they be able to find the captive, now placed at a considerable distance from her original position?

The cage was in darkness, almost in the open air. From time to time I visited it with a net and lantern. The visitors were captured, inspected, and immediately released in a neighbouring room, of which I closed the door. This gradual elimination allowed me to count the visitors exactly without danger of counting the same b.u.t.terfly more than once. Moreover, the provisional prison, large and bare, in no wise harmed or endangered the prisoners; they found a quiet retreat there and ample s.p.a.ce. Similar precautions were taken during the rest of my experiments.

After half-past ten no more arrived. The reception was over. Total, twenty-five males captured, of which one only was deprived of its antennae. So of the six operated on earlier in the day, which were strong enough to leave my study and fly back to the fields, only one had returned to the cage. A poor result, in which I could place no confidence as proving whether the antennae did or did not play a directing part. It was necessary to begin again upon a larger scale.

Next morning I visited the prisoners of the day before. What I saw was not encouraging. A large number were scattered on the ground, almost inert. Taken between the fingers, several of them gave scarcely a sign of life. Little was to be hoped from these, it would seem. Still, I determined to try; perhaps they would regain their vigour at the lover's hour.

The twenty-four prisoners were all subjected to the amputation of their antennae. The one operated on the day before was put aside as dying or nearly so. Finally the door of the prison was left open for the rest of the day. Those might leave who could; those could join in the carnival who were able. In order to put those that might leave the room to the test of a search, the cage, which they must otherwise have encountered at the threshold, was again removed, and placed in a room of the opposite wing, on the ground floor. There was of course free access to this room.

Of the twenty-four lacking their antennae sixteen only left the room.

Eight were powerless to do so; they were dying. Of the sixteen, how many returned to the cage that night? Not one. My captives that night were only seven, all new-comers, all wearing antennae. This result seemed to prove that the amputation of the antennae was a matter of serious significance. But it would not do to conclude as yet: one doubt remained.

"A fine state I am in! How shall I dare to appear before the other dogs?" said Mouflard, the puppy whose ears had been pitilessly docked.

Had my b.u.t.terflies apprehensions similar to Master Mouflard's? Deprived of their beautiful plumes, were they ashamed to appear in the midst of their rivals, and to prefer their suits? Was it confusion on their part, or want of guidance? Was it not rather exhaustion after an attempt exceeding the duration of an ephemeral pa.s.sion? Experience would show me.

On the fourth night I took fourteen new-comers and set them apart as they came in a room in which they spent the night. On the morrow, profiting by their diurnal immobility, I removed a little of the hair from the centre of the corselet or neck. This slight tonsure did not inconvenience the insects, so easily was the silky fur removed, nor did it deprive them of any organ which might later on be necessary in the search for the female. To them it was nothing; for me it was the unmistakable sign of a repeated visit.

This time there were none incapable of flight. At night the fourteen shavelings escaped into the open air. The cage, of course, was again in a new place. In two hours I captured twenty b.u.t.terflies, of whom two were tonsured; no more. As for those whose antennae I had amputated the night before, not one reappeared. Their nuptial period was over.

Of fourteen marked by the tonsure two only returned. Why did the other twelve fail to appear, although furnished with their supposed guides, their antennae? To this I can see only one reply: that the Great Peac.o.c.k is promptly exhausted by the ardours of the mating season.

With a view to mating, the sole end of its life, the great moth is endowed with a marvellous prerogative. It has the power to discover the object of its desire in spite of distance, in spite of obstacles. A few hours, for two or three nights, are given to its search, its nuptial flights. If it cannot profit by them, all is ended; the compa.s.s fails, the lamp expires. What profit could life hold henceforth? Stoically the creature withdraws into a corner and sleeps the last sleep, the end of illusions and the end of suffering.

The Great Peac.o.c.k exists as a b.u.t.terfly only to perpetuate itself. It knows nothing of food. While so many others, joyful banqueters, fly from flower to flower, unrolling their spiral trunks to plunge them into honeyed blossoms, this incomparable ascetic, completely freed from the servitude of the stomach, has no means of restoring its strength. Its buccal members are mere vestiges, useless simulacra, not real organs able to perform their duties. Not a sip of honey can ever enter its stomach; a magnificent prerogative, if it is not long enjoyed. If the lamp is to burn it must be filled with oil. The Great Peac.o.c.k renounces the joys of the palate; but with them it surrenders long life. Two or three nights--just long enough to allow the couple to meet and mate--and all is over; the great b.u.t.terfly is dead.

What, then, is meant by the non-appearance of those whose antennae I removed? Did they prove that the lack of antennae rendered them incapable of finding the cage in which the prisoner waited? By no means. Like those marked with the tonsure, which had undergone no damaging operation, they proved only that their time was finished. Mutilated or intact, they could do no more on account of age, and their absence meant nothing. Owing to the delay inseparable from the experiment, the part played by the antennae escaped me. It was doubtful before; it remained doubtful.

My prisoner under the wire-gauze cover lived for eight days. Every night she attracted a swarm of visitors, now to one part of the house, now to another. I caught them with the net and released them as soon as captured in a closed room, where they pa.s.sed the night. On the next day they were marked, by means of a slight tonsure on the thorax.

The total number of b.u.t.terflies attracted on these eight nights amounted to a hundred and fifty; a stupendous number when I consider what searches I had to undertake during the two following years in order to collect the specimens necessary to the continuation of my investigation.

Without being absolutely undiscoverable, in my immediate neighbourhood the coc.o.o.ns of the Great Peac.o.c.k are at least extremely rare, as the trees on which they are found are not common. For two winters I visited all the decrepit almond-trees at hand, inspected them all at the base of the trunk, under the jungle of stubborn gra.s.ses and undergrowth that surrounded them; and how often I returned with empty hands! Thus my hundred and fifty b.u.t.terflies had come from some little distance; perhaps from a radius of a mile and a quarter or more. How did they learn of what was happening in my study?