Chapter III. The Method of The Calicurgi
Jean-Henri Fabre More Hunting Wasp
Spider Wasp (Calicurgus Hyalinatus)
The non-armoured victims, vulnerable by the sting over almost their whole body, ordinary caterpillars and Looper caterpillars, Cetonia- and Anoxia-larvae, whose only means of defence, apart from their mandibles, consists of rollings and contortions, called for the testimony of another victim, the Spider, almost as ill-protected, but armed with formidable poison-fangs. How, in particular, will the Ringed Calicurgus set to work in operating on the Black-bellied Tarantula, the terrible Lycosa, who with a single bite kills the Mole or the Sparrow and endangers the life of man? How does the bold Pompilus overcome an adversary more powerful than herself, better-equipped with virulent poison and capable of making a meal of her assailant? Of all the Hunting Wasps, none risks such unequal conflicts, in which appearances would proclaim the aggressor to be the victim and the victim the aggressor.
The problem was one deserving patient study. True, I foresaw, from the Spider's organization, a single sting in the centre of the thorax; but that did not explain the victory of the Wasp, emerging safe and sound from her tussle with such a quarry. I had to see what occurred. The chief difficulty was the scarcity of the Calicurgus. It is easy for me to obtain the Tarantula at the desired moment: the part of the plateau in my neighbourhood left untilled by the vine-growers provides me with as many as are necessary. To capture the Pompilus is another matter. I have so little hope of finding her that special quests are regarded as useless. To search for her would perhaps be just the way not to find her. Let us rely on the uncertainties of chance. Shall I get her or shall I not?
I've got her. I catch her unexpectedly on the flowers. Next day I supply myself with half a dozen Tarantulae. Perhaps I shall be able to employ them one after the other in repeated duels. As I return from my Lycosa-hunt, luck smiles upon me again and crowns my desires. A second Calicurgus offers herself to my net; she is dragging her heavy, paralysed Spider by one leg, in the dust of the highway. I attach great value to my find: the laying of the egg has become a pressing matter; and the mother, I believe, will accept a substitute for her victim without much hesitation. Here then are my two captives, each under her bell-glass with her Tarantula.
I am all eyes. What a tragedy there will be in a moment! I wait, anxiously…But…but…what is this? Which of the two is the assailed? Which is the assailant? The characters seem to be inverted. The Calicurgus, unable to climb up the smooth glass wall, strides round the ring of the circus. With a proud and rapid gait, her wings and antennae vibrating, she goes and returns. The Lycosa is soon seen. The Calicurgus approaches her without the least sign of fear, walks round her and appears to have the intention of seizing one of her legs. But at that moment the Tarantula rises almost vertically on her four hinder legs, with her four front legs lifted and outspread, ready for the counterstroke. The poison-fangs gape widely; a drop of venom moistens their tips. The very sight of them makes my flesh creep. In this terrible attitude, presenting her powerful thorax and the black velvet of her belly to the enemy, the Spider overawes the Pompilus, who suddenly turns tail and moves away. The Lycosa then closes her bundle of poisoned daggers and resumes her natural pose, standing on her eight legs; but, at the slightest attempt at aggression on the Wasp's part, she resumes her threatening position.
She does more: suddenly she leaps and flings herself upon the Calicurgus; swiftly she clasps her and nibbles at her with her fangs. Without wielding her sting in self-defence, the other disengages herself and merges unscathed from the angry encounter. Several times in succession I witness the attack; and nothing serious ever befalls the Wasp, who swiftly withdraws from the fray and appears to have received no hurt. She resumes her marching and countermarching no less boldly and swiftly than before.
Is this Wasp invulnerable, that she thus escapes from the terrible fangs? Evidently not. A real bite would be fatal to her. Big, sturdily built Acridians succumb (1); how is it that she, with her delicate organism, does not! The Spider's daggers, therefore, make no more than an idle feint; their points do not enter the flesh of the tight-clasped Wasp. If the strokes were real, I should see bleeding wounds, I should see the fangs close for a moment on the part seized; and with all my attention I cannot detect anything of the kind. Then are the fangs powerless to pierce the Wasp's integuments? Not so. I have seen them penetrate, with a crackling of broken armour, the corselet of the Acridians, which offers a far greater resistance. Once again, whence comes this strange immunity of the Calicurgus held between the legs and assailed by the daggers of the Tarantula? I do not know. Though in mortal peril from the enemy confronting her, the Lycosa threatens her with her fangs and cannot decide to bite, owing to a repugnance which I do not undertake to explain.
Obtaining nothing more than alarums and excursions of no great seriousness, I think of modifying the gladiatorial arena and approximating it to natural conditions. The soil is very imperfectly represented by my work-table; and the Spider has not her fortress, her burrow, which plays a part of some importance both in attack and in defence. A short length of reed is planted perpendicularly in a large earthenware pan filled with sand. This will be the Lycosa's burrow. In the middle I stick some heads of globe-thistle garnished with honey as a refectory for the Pompilus; a couple of Locusts, renewed as and when consumed, will sustain the Tarantula. These comfortable quarters, exposed to the sun, receive the two captives under a wire-gauze dome, which provides adequate ventilation for a prolonged residence.
My artifices come to nothing; the session closes without result. A day passes, two days, three; still nothing happens. The Pompilus is assiduous in her visits to the honeyed flower-clusters; when she has eaten her fill, she clambers up the dome and makes interminable circuits of the netting; the Tarantula quietly munches her Locust. If the other passes within reach, she swiftly raises herself and waves her off. The artificial burrow, the reed-stump, fulfills its purpose excellently. The Lycosa and the Pompilus resort to it in turns, but without quarrelling. And that is all. The drama whose prologue was so full of promise appears to be indefinitely postponed.
I have a last resource, on which I base great hopes: it is to remove my two Calicurgi to the very site of their investigations and to install them at the door of the Spider's lodging, at the top of the natural burrow. I take the field with an equipment which I am carrying across the country for the first time: a glass bell-jar, a wire-gauze cover and the various implements needed for handling and transferring my irascible and dangerous subjects. My search for burrows among the pebbles and the tufts of thyme and lavender is soon successful.
Here is a splendid one. I learn by inserting a straw that it is inhabited by a Tarantula of a size suited to my plans. The soil around the aperture is cleared and flattened to receive the wire-gauze, under which I place a Pompilus. This is the time to light a pipe and wait, lying on the pebbles…Yet another disappointment. Half an hour goes by; and the Wasp confines herself to travelling round and round the netting as she did in my study. She gives no sign of greed when confronted with the burrow, though I can see the Tarantula's diamond eyes glittering at the bottom.
The trellised wall is replaced by the glass wall, which, since it does not allow her to scale its heights, will oblige the Wasp to remain on the ground and at last to take cognizance of the shaft, which she seems to ignore. This time we have done the trick!
After a few circuits of her cage, the Calicurgus notices the pit yawning at her feet. She goes down it. This daring confounds me. I should never have ventured to anticipate as much. That she should suddenly fling herself upon the Tarantula when the latter is outside her stronghold, well and good; but to rush into the lair, when the terrible monster is waiting for you below with those two poisoned daggers of hers! What will come of such temerity? A buzzing of wings ascends from the depths. Run to earth in her private apartments, the Lycosa is no doubt at grips with the intruder. That hum of wings is the Calicurgus' paean of triumph, until it be her death-song. The slayer may well be the slain. Which of the two will come up alive?
It is the Lycosa, who hurriedly scampers out and posts herself just over the orifice of the burrow, in her posture of defence, her fangs open, her four front legs uplifted. Can the other have been stabbed? Not at all, for she emerges in her turn, not without receiving on the way a cuff from the Spider, who immediately regains her lair. Dislodged from her basement a second and yet a third time, the Tarantula always comes up unwounded; she always awaits her adversary on her threshold, administers punishment and reenters her dwelling. In vain do I try my two Pompili alternately and change the burrow; I do not succeed in observing anything else. Certain conditions not realized by my stratagems are lacking to complete the tragedy.
Discouraged by the repetition of my futile attempts, I throw up the game, the richer however by one fact of some value: the Calicurgus, without the least fear, descends into the Tarantula's den and dislodges her. I imagine that things happen in the same fashion outside my cages. When expelled from her dwelling, the Spider is more timid and more vulnerable to attack. Moreover, while hampered by a narrow shaft, the operator would not wield her lancet with the precision called for by her designs. The bold irruption shows us once again, more plainly than the tussles on my table, the Lycosa's reluctance to sink her fangs into her enemy's body. When the two are face to face at the bottom of the lair, then or never is the moment to have it out with the foe. The Tarantula is in her own house, with all its conveniences; every nook and corner of the bastion is familiar to her. The intruder's movements are hampered by her ignorance of the premises. Quick, my poor Lycosa, quick, a bite; and it's all up with your persecutor! But you refrain, I know not why, and your reluctance is the saving of the rash invader. The silly Sheep does not reply to the butcher's knife by charging with lowered horns. Can it be that you are the Pompilus' Sheep?
My two subjects are reinstalled in my study under their wire-gauze covers, with bed of sand, reed-stump burrow and fresh honey, complete. Here they find again their first Lycosae, fed upon Locusts. Cohabitation continues for three weeks without other incidents than scuffles and threats which become less frequent day by day. No serious hostility is displayed on either side. At last the Calicurgi die: their day is over. A pitiful end after such an enthusiastic beginning.
Shall I abandon the problem? Why, not a bit of it! I have encountered greater difficulties, but they have never deterred me from a warmly-cherished project. Fortune favours the persevering. She proves as much by offering me, in September, a fortnight after the death of my Tarantula-huntresses, another Calicurgus, captured for the first time. This is the Harlequin Calicurgus (C. scurra, LEP.), who sports the same gaudy costume as the first and is almost of the same size.
Now what does this newcomer, of whom I know nothing, want? A Spider, that is certain; but which? A huntress like this will need a corpulent quarry: perhaps the Silky Epeira (E. serica), perhaps the Banded Epeira (E. fasciata), the largest Spiders in the district, next to the Tarantula. The first of these spreads her large upright net, in which Locusts are caught, from one clump of brushwood to another. I find her in the copses on the neighbouring hills. The second stretches hers across the ditches and the little streams frequented by the Dragon-flies. I find her near the Aygues, beside the irrigation-canals fed by the torrent. A couple of trips procures me the two Epeirae, whom I offer to my captive next day, both at the same time. It is for her to choose according to her taste.
The choice is soon made: the Banded Epeira is the one preferred. But she does not yield without protest. On the approach of the Wasp, she rises and assumes a defensive attitude, just like that of the Lycosa. The Calicurgus pays no attention to threats: under her harlequin's coat, she is violent in attack and quick on her legs. There is a rapid exchange of fisticuffs; and the Epeira lies overturned on her back. The Pompilus is on top of her, belly to belly, head to head; with her legs she masters the Spider's legs; with her mandibles she grips the cephalothorax. She curves her abdomen, bringing the tip of it beneath her; she draws her sting and…
One moment, reader, if you please. Where is the sting about to strike? From what we have learnt from the other paralysers, it will be driven into the breast, to suppress the movement of the legs. That is your opinion; it was also mine. Well, without blushing too deeply at our common and very excusable error, let us confess that the insect knows better than we do. It knows how to assure success by a preparatory manoeuvre of which you and I had never dreamt. Ah, what a school is that of the animals! Is it not true that, before striking the adversary, you should take care not to get wounded yourself? The Harlequin Pompilus does not disregard this counsel of prudence. The Epeira carries beneath her throat two sharp daggers, with a drop of poison at their points; the Calicurgus is lost if the Spider bites her. Nevertheless, her anaesthetizing demands perfect steadiness of the lancet. What is to be done in the face of this danger which might disconcert the most practised surgeon? The patient must first be disarmed and then operated on.
And in fact the Calicurgus' sting, aimed from back to front, is driven into the Epeira's mouth, with minute precautions and marked persistency. On the instant, the poison-fangs close lifelessly and the formidable quarry is powerless to harm. The Wasp's abdomen then extends its arc and drives the needle behind the fourth pair of legs, on the median line, almost at the junction of the belly and the cephalothorax. At this point the skin is finer and more easily penetrable than elsewhere. The remainder of the thoracic surface is covered with a tough breast-plate which the sting would perhaps fail to perforate. The nerve-centres, the source of the leg-movements, are situated a little above the wounded point, but the back-to-front direction of the sting makes it possible to reach them. This last wound results in the paralysis of all the eight legs at once.
To enlarge upon it further would detract from the eloquence of this performance. First of all, to safeguard the operator, a stab in the mouth, that point so terribly armed, the most formidable of all; then, to safeguard the larva, a second stab in the nerve-centres of the thorax, to suppress the power of movement. I certainly suspected that the slayers of robust Spiders were endowed with special talents; but I was far from expecting their bold logic, which disarms before it paralyses. So the Tarantula-huntress must behave, who, under my bell-glasses, refused to surrender her secret. I now know what her method is; it has been divulged by a colleague. She throws the terrible Lycosa upon her back, pricks her prickers by stinging her in the mouth and then, in comfort, with a single thrust of the lancet, obtains paralysis of the legs.
I examine the Epeira immediately after the operation and the Tarantula when the Calicurgus is dragging her by one leg to her burrow, at the foot of some wall. For a little while longer, a minute at most, the Epeira convulsively moves her legs. So long as these throes continue, the Pompilus does not release her prey. She seems to watch the progress of the paralysis. With the tips of her mandibles she explores the Spider's mouth several times over, as though to ascertain if the poison-fangs are really innocuous. When all movement subsides, the Pompilus makes ready to drag her prey elsewhere. It is then I take charge of it.
What strikes me more than anything else is the absolute inertia of the fangs, which I tickle with a straw without succeeding in rousing them from their torpor. The palpi, on the other hand, their immediate neighbours, wave at the least touch. The Epeira is placed in safety, in a flask, and undergoes a fresh examination a week later. Irritability has in part returned. Under the stimulus of a straw, I see her legs move a little, especially the lower joints, the tibiae and tarsi. The palpi are even more irritable and mobile. These different movements, however, are lacking in vigour and coordination; and the Spider cannot employ them to turn over, much less to escape. As for the poison-fangs, I stimulate them in vain: I cannot get them to open or even to stir. They are therefore profoundly paralysed and in a special manner. The peculiar insistence of the sting when the mouth was stabbed told me as much in the beginning.
At the end of September, almost a month after the operation, the Epeira is in the same condition, neither dead nor alive: the palpi still quiver when touched with a straw, but nothing else moves. At length, after six or seven weeks' lethargy, real death supervenes, together with its comrade, putrefaction.
The Tarantula of the Ringed Calicurgus, as I take her from the owner at the moment of transportation, presents the same peculiarities. The poison-fangs are no longer irritable when tickled with my straw: a fresh proof, added to those of analogy, to show that the Lycosa, like the Epeira, has been stung in the mouth. The palpi, on the other hand, are and will be for weeks highly irritable and mobile. I wish to emphasise this point, the importance of which will be recognized presently.
I found it impossible to provoke a second attack from my Harlequin Calicurgus: the tedium of captivity did not favour the exercise of her talents. Moreover, the Epeira sometimes had something to do with her refusals; a certain ruse de guerre which was twice employed before my eyes may well have baffled the aggressor. Let me describe the incident, if only to increase our respect a little for these foolish Spiders, who are provided with perfected weapons and do not dare to make use of them against the weaker but bolder assailant.
The Epeira occupies the wall of the wire-gauze cage, with her eight legs wide-spread upon the trelliswork; the Calicurgus is wheeling round the top of the dome. Seized with panic at the sight of the approaching enemy, the Spider drops to the ground, with her belly upwards and her legs gathered together. The other dashes forward, clasps her round the body, explores her and prepares to sting her in the mouth. But she does not bare her weapon. I see her bending attentively over the poisoned fangs, as though to investigate their terrible mechanism; she then goes away. The Spider is still motionless, so much so that I really believe her dead, paralysed unknown to me, at a moment when I was not looking. I take her from the cage to examine her comfortably. No sooner is she placed on the table than behold, she comes to life again and promptly scampers off! The cunning creature was shamming death beneath the Wasp's stiletto, so artfully that I was taken in. She deceived an enemy more cunning than myself, the Pompilus, who inspected her very closely and took her for a corpse unworthy of her dagger. Perhaps the simple creature, like the Bear in the fable of old, already noticed the smell of high meat.
This ruse, if ruse it be, appears to me more often than not to turn to the disadvantage of the Spider, whether Tarantula, Epeira or another. The Calicurgus who has just put the Spider on her back after a brisk fight knows quite well that her prostrate foe is not dead. The latter, thinking to protect itself, simulates the inertia of a corpse; the assailant profits by this to deliver her most perilous blow, the stab in the mouth. Were the fangs, each tipped with its drop of poison, to open then; were they to snap, to give a desperate bite, the Pompilus would not dare to expose the tip of her abdomen to their deadly scratch. The shamming of death is exactly what enables the huntress to succeed in her dangerous operation. They say, O guileless Epeirae, that the struggle for life has taught you to adopt this inert attitude for purposes of defence. Well, the struggle for life was a very bad counsellor. Trust rather to common sense and learn, by degrees, at your own cost, that to hit back, above all if you can do so promptly, is still the best way to intimidate the enemy (2).
The remainder of my observations on these insects under glass is little more than a long series of failures. Of two operators on Weevils, one, the Sandy Cerceris (C. arenaria), persistently scorned the victims offered; the other, Ferrero's Cerceris (C. Ferreri), allowed herself to be empted after two days' captivity. Her tactical method, as I expected, is precisely that of the Cleonus-huntress, the Great Cerceris, with whom my investigations commenced. When confronted with the Acorn-weevil, she seizes the insect by the snout, which is immensely long and shaped like a pipe-stem, and plants her sting in its body to the rear of the prothorax, between the first and second pair of legs. It is needless to insist: the spoiler of the Cleoni has taught us enough about this mode of operation and its results.
None of the Bembex-wasps, whether chosen among the huntresses of the Gadfly or among the lovers of the House-fly rabble, satisfied my aspirations. Their method is as unknown to me now as at the distant period when I used to watch it in the Bois des Issards (3). Their impetuous flight, their love of long journeys are incompatible with captivity. Stunned by colliding with the walls of their glass or wire-gauze prison, they all perish within twenty-four hours. Swifter in their movements and apparently satisfied with their honeyed thistle-heads, the Spheges, huntresses of Crickets or Ephippigers, die as quickly of nostalgia. All I offer them leaves them indifferent.
Nor can I get anything out of the Eumenes, notably the biggest of them, the builder of gravel cupolas, Amedeus' Eumenes. All the Pompili, except the Harlequin Calicurgus, refuse my Spiders. The Palarus, who preys upon an indefinite number of the Hymenopteron clan, refuses to tell me if she drinks the honey of the Bees, as does the Philanthus, or if she lets the others go without manipulating them to make them disgorge. The Tachytes do not vouchsafe their Locusts a glance; Stizus ruficornis promptly gives up the ghost, disdaining the Praying Mantis which I provide for her.
What is the use of continuing this list of checks? The rule may be gathered from these few examples: occasional successes and many failures. What can be the reason? With the exception of the Philanthus, tempted from time to time by a bumper of honey, the predatory Wasps do not hunt on their own account; they have their victualling-time, when the egg-laying is imminent, when the family calls for food. Outside these periods, the finest heads of game might well leave these nectar-bibbers indifferent. I am careful therefore, as far as possible, to capture my subjects at the proper season; I give preference to mothers caught upon the threshold of the burrow with their prey between their legs. This diligence of mine by no means always succeeds. There are demoralized insects which, once under glass, even after a brief delay, no longer care about the equivalent of their prize.
All the species do not perhaps pursue their game with the same ardour; mood and temperament are more variable even than conformation. To these factors, which are of the nicest order, we may add that of the hour, which is often unfavourable when the subject is caught at haphazard on the flowers, and we shall have more than enough to explain the frequency of the failures. After all, I must beware of representing my failures as the rule: what does not succeed one day may very well succeed another day, under different conditions. With perseverance and a little skill, any one who cares to continue these interesting studies will, I am sure, fill up many gaps. The problem is difficult but not impossible.
I will not quit my bell-jars without saying a word on the entomological tact of the captives when they decide to attack. One of the pluckiest of my subjects, the Hairy Ammophila, was not always provided with the hereditary dish of her family, the Grey Worm. I offered her indiscriminately any bare-skinned caterpillars that I chanced to find. Some were yellow, some green, some brown with white edges. All were accepted without hesitation, provided that they were of suitable size. Tasty game was recognized wonderfully under very dissimilar liveries. But a young Zeuzera-caterpillar, dug out of the branches of a lilac-tree, and a silkworm of small dimensions were definitely refused. The over-fed products of our silkworm-nurseries and the mystery-loving caterpillar which gnaws the inner wood of the lilac inspired her with suspicion and disgust, despite their bare skin, which favoured the sting, and their shape, which was similar to that of the victims accepted.
Another ardent huntress, the Interrupted Scolia, refused the Cetonia-grub, which is of like habits with the Anoxia-larva; the Two-banded Scolia also refused the Anoxia. The Philanthus, the headlong murderess of Bees, saw through my trickery when I confronted her with the Virgilian Bee, the Eristalis (E. tenax). She, a Philanthus, take this Fly for a Bee! What next! The popular idea is mistaken; antiquity too is mistaken, as witness the „Georgics,“ which make the putrid remains of a sacrificed Bull give birth to a swarm; but the Wasp makes no mistake. In her eyes, which see farther than ours, the Eristalis is an odious Dipteron, a lover of corruption, and nothing more.
1. Locusts and Grasshoppers.
2. Fabre does not believe in the actual shamming of death by animals. Cf. „The Glow-worm and Other Beetles,“ by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chapters 8 to 15.
3. Cf. „The Hunting Wasps“: chapters 14 to 18.