More Hunting Wasps

by Jean-Henri Fabre

"At the moment of the bite, the sensation was sharp enough to deserve the name of pain; and this continued for five or six minutes more, but not so forcibly. I might compare it with the sensation produced by the stinging-nettle. A whitish tumefaction almost immediately surrounded the two pricks; and the circumference, within a radius of about an inch, was coloured an erysipelas red, accompanied by a very slight swelling. In an hour and a half, it had all disappeared, except the mark of the pricks, which persisted for several days, as any other small wound would have done. This was in September, in rather cool weather. Perhaps the symptoms would have displayed somewhat greater severity at a warmer season."

Without being serious, the effect of the Segestria's poison is plainly marked. A sting causing sharp pain and swelling, with the redness of erysipelas, is no trifling matter. While Duges' experiment reassures us in so far as we ourselves are concerned, it is none the less the fact that the Cellar Spider's poison is a terrible thing for insects, whether because of the small size of the victim, or because it acts with special efficacy upon an organization which differs widely from our own. One Pompilus, though greatly inferior to the Segestria in size and strength, nevertheless makes war upon the Black Spider and succeeds in overpowering this formidable quarry. This is Pompilus apicalis, VAN DER LIND, who is hardly larger than the Hive-bee, but very much slenderer. She is of a uniform black; her wings are a cloudy brown, with transparent tips. Let us follow her in her expeditions to the old wall inhabited by the Segestria: we will track her for whole afternoons during the July heats; and we will arm ourselves with patience, for the perilous capture of the game must take the Wasp a long time.

The Spider-huntress explores the wall minutely; she runs, leaps and flies; she comes and goes, flitting to and fro. The antennae quiver; the wings, raised above the back, continually beat one against the other. Ah, here she is, close to a Segestria's funnel! The Spider, who has hitherto remained invisible, instantly appears at the entrance to the tube; she spreads her six fore-legs outside, ready to receive the huntress. Far from fleeing before the terrible apparition, she watches the watcher, fully prepared to prey upon her enemy. Before this intrepid demeanour the Pompilus draws back. She examines the coveted game, walks round it for a moment, then goes away without attempting anything. When she has gone, the Segestria retires indoors, backwards. For the second time the Wasp passes near an inhabited funnel. The Spider on the lookout at once shows herself on the threshold of her dwelling, half out of her tube, ready for defence and perhaps also for attack. The Pompilus moves away and the Segestria reenters her tube. A fresh alarm: the Pompilus returns; another threatening demonstration on the part of the Spider. Her neighbour, a little later, does better than this: while the huntress is prowling about in the neighbourhood of the funnel, she suddenly leaps out of the tube, with the lifeline which will save her from falling, should she miss her footing, attached to her spinnerets; she rushes forward and hurls herself in front of the Pompilus, at a distance of some eight inches from her burrow. The Wasp, as though terrified, immediately decamps; and the Segestria no less suddenly retreats indoors.

Here, we must admit, is a strange quarry: it does not hide, but is eager to show itself; it does not run away, but flings itself in front of the hunter. If our observations were to cease here, could we say which of the two is the hunter and which the hunted? Should we not feel sorry for the imprudent Pompilus? Let a thread of the trap entangle her leg; and it is all up with her. The other will be there, stabbing her in the throat. What then is the method which she employs against the Segestria, always on the alert, ready for defence, audacious to the point of aggression? Shall I surprise the reader if I tell him that this problem filled me with the most eager interest, that it held me for weeks in contemplation before that cheerless wall? Nevertheless, my tale will be a short one.

On several occasions I see the Pompilus suddenly fling herself on one of the Spider's legs, seize it with her mandibles and endeavour to draw the animal from its tube. It is a sudden rush, a surprise attack, too quick to permit the Spider to parry it. Fortunately, the latter's two hind-legs are firmly hooked to the dwelling; and the Segestria escapes with a jerk, for the other, having delivered her shock attack, hastens to release her hold; if she persisted, the affair might end badly for her. Having failed in this assault, the Wasp repeats the procedure at other funnels; she will even return to the first when the alarm is somewhat assuaged. Still hopping and fluttering, she prowls around the mouth, whence the Segestria watches her, with her legs outspread. She waits for the propitious moment; she leaps forward, seizes a leg, tugs at it and springs out of reach. More often than not, the Spider holds fast; sometimes she is dragged out of the tube, to a distance of a few inches, but immediately returns, no doubt with the aid of her unbroken lifeline.

The Pompilus' intention is plain: she wants to eject the Spider from her fortress and fling her some distance away. So much perseverance leads to success. This time all goes well: with a vigorous and well-timed tug the Wasp has pulled the Segestria out and at once lets her drop to the ground. Bewildered by her fall and even more demoralized by being wrested from her ambush, the Spider is no longer the bold adversary that she was. She draws her legs together and cowers into a depression in the soil. The huntress is there on the instant to operate on the evicted animal. I have barely time to draw near to watch the tragedy when the victim is paralysed by a thrust of the sting in the thorax.

Here at last, in all its Machiavellian cunning, is the shrewd method of the Pompilus. She would be risking her life if she attacked the Segestria in her home; the Wasp is so convinced of it that she takes good care not to commit this imprudence; but she knows also that, once dislodged from her dwelling, the Spider is as timid, as cowardly as she was bold at the centre of her funnel. The whole point of her tactics, therefore, lies in dislodging the creature. This done, the rest is nothing.

The Tarantula-huntress must behave in the same manner. Enlightened by her kinswoman, Pompilus apicalis, my mind pictures her wandering stealthily around the Lycosa's rampart. The Lycosa hurries up from the bottom of her burrow, believing that a victim is approaching; she ascends her vertical tube, spreading her fore-legs outside, ready to leap. But it is the Ringed Pompilus who leaps, seizes a leg, tugs and hurls the Lycosa from her burrow. The Spider is henceforth a craven victim, who will let herself be stabbed without dreaming of employing her venomous fangs. Here craft triumphs over strength; and this craft is not inferior to mine, when, wishing to capture the Tarantula, I make her bite a spike of grass which I dip into the burrow, lead her gently to the surface and then with a sudden jerk throw her outside. For the entomologist as for the Pompilus, the essential thing is to make the Spider leave her stronghold. After this there is no difficulty in catching her, thanks to the utter bewilderment of the evicted animal.

Two contrasting points impress me in the facts which I have just set forth: the shrewdness of the Pompilus and the folly of the Spider. I will admit that the Wasp may gradually have acquired, as being highly beneficial to her posterity, the instinct by which she first of all so judiciously drags the victim from its refuge, in order there to paralyse it without incurring danger, provided that you will explain why the Segestria, possessing an intellect no less gifted than that of the Pompilus, does not yet know how to counteract the trick of which she has so long been the victim. What would the Black Spider need to do to escape her exterminator? Practically nothing: it would be enough for her to withdraw into her tube, instead of coming up to post herself at the entrance, like a sentry, whenever the enemy is in the neighbourhood. It is very brave of her, I agree, but also very risky. The Pompilus will pounce upon one of the legs spread outside the burrow for defence and attack; and the besieged Spider will perish, betrayed by her own boldness. This posture is excellent when waiting for prey. But the Wasp is not a quarry; she is an enemy and one of the most dreaded of enemies. The Spider knows this. At the sight of the Wasp, instead of placing herself fearlessly but foolishly on her threshold, why does she not retreat into her fortress, where the other would not attack her? The accumulated experience of generations should have taught her this elementary tactical device, which is of the greatest value to the prosperity of her race. If the Pompilus has perfected her method of attack, why has not the Segestria perfected her method of defence? Is it possible that centuries upon centuries should have modified the one to its advantage without succeeding in modifying the other? Here I am utterly at a loss. And I say to myself, in all simplicity: since the Pompili must have Spiders, the former have possessed their patient cunning and the other their foolish audacity from all time. This may be puerile, if you like to think it so, and not in keeping with the transcendental aims of our fashionable theorists; the argument contains neither the subjective nor the objective point of view, neither adaptation nor differentiation, neither atavism nor evolutionism. Very well, but at least I understand it.

Let us return to the habits of Pompilus apicalis. Without expecting results of any particular interest, for in captivity the respective talents of the huntress and the quarry seem to slumber, I place together, in a wide jar, a Wasp and a Segestria. The Spider and her enemy mutually avoid each other, both being equally timid. A judicious shake or two brings them into contact. The Segestria, from time to time, catches hold of the Pompilus, who gathers herself up as best she can, without attempting to use her sting; the Spider rolls the insect between her legs and even between her mandibles, but appears to dislike doing it. Once I see her lie on her back and hold the Pompilus above her, as far away as possible, while turning her over in her fore-legs and munching at her with her mandibles. The Wasp, whether by her own adroitness or owing to the Spider's dread of her, promptly escapes from the terrible fangs, moves to a short distance and does not seem to trouble unduly about the buffeting which she has received. She quietly polishes her wings and curls her antennae by pulling them while standing on them with her fore-tarsi. The attack of the Segestria, stimulated by my shakes, is repeated ten times over; and the Pompilus always escapes from the venomous fangs unscathed, as though she were invulnerable.