THE GOLD BEETLES: THEIR NUPTIAL HABITS

It is admitted that, as an ardent destroyer of caterpillars and Slugs, the Gold Beetle has pre-eminently earned his title of “Gardener”: he is the watchful keeper of our kitchen-gardens and our flower-borders. If my enquiries add nothing to his established reputation in this respect, they will at least, in what follows, display the insect in an as yet unsuspected light. The ferocious eater, the ogre devouring any prey not beyond his powers, is eaten in his turn. And by whom? By his own kin and many others.

We will begin by naming two of his enemies, the Fox and the Toad, who, in hard times, for lack of anything better, do not disdain such lean and caustic mouthfuls. When telling the story of the Trox, I described how the excreta of the Fox, which are easily recognized by the Rabbit’s-fur whereof they largely consist, are sometimes encrusted with Gold Beetles’ wing-cases: the ordure is adorned with sheets of gold. This testifies to the bill of fare. It is not highly nourishing nor particularly plentiful and it tastes bitter; but, after all, a few Carabi help to stay the appetite a little.

As regards the Toad, I have similar evidence. In summer, in the garden-paths, from time to time I happen on some curious objects whose origin at first leaves me quite undecided. They are small black sausages, the thickness of my little finger, which crumble very easily after drying in the sun. We recognize a conglomeration of Ants’ heads and nothing besides, unless it be some remnants of slender leg. What can this singular product be, this granular amalgam consisting of hundreds and hundreds of heads packed close together?

One’s mind turns to a ball disgorged by the Owl after the nourishing part has been sorted by the stomach. Further reflection discards the idea: a nocturnal bird of prey, though fond of insects, does not feed on such tiny game as this. To catch on the sticky tip of the tongue such very small fry and to collect them one by one calls for a consumer endowed with plenty of time and patience. Who is it? Could it be the Toad? I see no other in the enclosure to whom I can attribute a salmagundy of Ants. Experiment will solve the riddle for us.

I have an old acquaintance in the garden and I know where he lives. We often meet at the hour of my evening rounds. He looks at me with his gold-yellow eyes and gravely passes on to attend to his business. He is a Toad big enough to fill a saucer, a veteran respected by the whole household. We call him the Philosopher. I apply to him to elucidate the question of the conglomerations of Ants’ heads.

I imprison him in a cage, without any food, and wait until the contents of his sated paunch undergo the labours of digestion. Things do not take very long. After a few days’ time, the prisoner presents me with a specimen of black ordure, moulded into a cylinder, exactly resembling those which I observe on the paths of the enclosure. It is, like the others, an amalgam of Ants’ heads. I restore the Philosopher to liberty. Thanks to him, the problem which puzzled me so greatly is solved: I know for certain that the Toad is a great eater of Ants, a very small quarry, it is true, but easy to collect and inexhaustible.

It is not always a free choice on his part. He prefers larger mouthfuls when available. He lives mainly on Ants because they abound in the enclosure, whereas the other insects running on the surface of the ground are comparatively scarce. If occasionally the glutton finds more sumptuous fare, he appreciates the feast all the more highly.

In evidence of these unusual banquets, I will mention certain dejecta found in the enclosure and composed almost entirely of Gold Beetles’ wing-cases. The remainder of the product, the paste joining the golden scales together, consisted of Ants’ heads, the authentic work of the consumer. So the Toad feeds on Carabi when he has the opportunity. He, our garden helper, robs us of another helper no less valuable. The useful, from our point of view, destroys the useful: a little lesson which should modify our ingenuous belief that all things are created for our service.

There is worse to come. The Gold Beetle, the policeman who, in our gardens, keeps an eye on the misdeeds of the caterpillar and the Slug, is guilty of the vice of cannibalism. One day, in the shadow of the plane-trees outside my door, I see one passing very busily. The pilgrim is welcome: he will increase by one the colony in my vivarium. As I capture him, I perceive that the tips of his wing-cases are slightly damaged. Is this the result of a fight between rivals? There is nothing to tell me. The great thing is that the Beetle should not be handicapped by a serious injury. I examine him, find that he is unwounded and fit for service and put him among the twenty-five occupants of the glass cage.

Next day, I look for the new inmate. He is dead. His comrades have attacked him during the night and cleaned out his abdomen, which was inadequately protected by the injured wing-cases. The operation was very neatly done, without any mutilation. Legs, head, corselet are all in their right places; only the abdomen has a wide opening through which its contents have been removed. What we see is a sort of golden shell formed of two connected wing-cases. An Oyster-shell emptied of its mollusc looks no cleaner.

This result astonishes me, for I take very good care that the cage is never without provisions. The Snail, the Cockchafer, the Praying Mantis, the Earthworm, the caterpillar and other favourite dishes alternate in my refectory in more than sufficient quantities. My Gold Beetles therefore had not the excuse of hunger in devouring a brother whose damaged armour lent itself to easy attack.

Can it be their custom to finish off the wounded and to ransack the stomach of an injured kinsman? Pity is unknown among the insects. At the sight of the desperate struggles of a crippled relation, not one of the same race will stop, not one will try to help him. With carnivorous insects, matters may take an even more tragic turn. Sometimes the passers-by will run up to the invalid. Do they do so in order to assist him? Not at all: they do it to see what he tastes like and, if they find him good, to cure his ills thoroughly by devouring him.

It is therefore possible that the Carabus with the damaged wing-cases tempted his comrades by the sight of his partly denuded body. They saw in their helpless brother a prey which it was lawful to dissect. But do they respect one another when there is no previous injury? At first sight, everything would seem to show that their relations are very peaceful. There is never any scuffling between the feasters at their meals, nothing but mouth-to-mouth robberies. Nor are there any quarrels during the long siestas under the cover of the board. Half-buried in the cool earth, my five-and-twenty specimens quietly slumber and digest their food, at no great distance one from the other, each in his little trench. If I take away the shelter, they awake, make off, run hither and thither, constantly meeting without molesting one another.

Profound peace therefore prevails and seems likely to last for ever when, on inspecting the cage during the first heats of June, I find a dead Carabus. His limbs are intact; he is very neatly reduced to a mere golden husk; he shows us once more what we saw in the helpless Beetle who was lately devoured; he reminds us of the shell of the eaten Oyster. I examine the remains. But for the huge breach in the abdomen, all is as it should be. So the insect was in good health when the others gutted it.

A few days later, yet another Carabus is slain and treated like the others, with all the various pieces of the armour undisturbed. If we lay him on his belly, he seems as though intact; if we lay him on his back, he is hollow, without a scrap of flesh left inside his carapace. A little later I find another empty relic, then another, and yet another, until my menagerie is rapidly diminishing. If this frenzied slaughter continues, I shall soon have nothing left in the vivarium.

Can it be that my Gold Beetles, worn out by age, die a natural death or that the females batten on the corpses, or is the population being reduced at the expense of hale and hearty subjects? It is not easy to elucidate the matter, for the disembowelling usually takes place at night. Nevertheless, by exerting vigilance, I twice succeed in observing the autopsy by daylight.

In the middle of June, before my eyes a female sets to work upon a male, whom I recognize as such by his rather smaller size. The operation begins. Lifting the ends of the wing-cases, the assailant seizes her victim by the tip of the abdomen, on the dorsal surface. Eagerly she tugs and munches. The captive, though in the pink of condition, does not defend himself, does not turn round. He pulls his hardest in the opposite direction, to release himself from the terrible mandibles; he moves this way or that, according as he is dragging his aggressor or being dragged by her; and here his resistance ends. The combat lasts a quarter of an hour. Other Beetles passing by, stop, as though to say:

“My turn next.”

At last, redoubling his efforts, the male frees himself and escapes. No doubt, if he had not succeeded in getting away, he would have had his belly gutted by the fearsome dame.

A few days later I witness a similar scene, but this time the tragedy is completed. Once more it is a female who seizes a male from behind. The bitten one submits with no more protest than his vain efforts to release himself. The skin at last gives way, the wound widens, the viscera are rooted out and swallowed by the matron, who empties the carapace with her head buried in her compeer’s belly. The tremors of the poor wretch’s legs announce his approaching end. The murderess takes no notice and continues to rummage as far up as the narrow entrance to the thorax allows her to go. Nothing is left of the deceased but the wing-cases, packed boat-wise, and the fore-part of the body, which is not disjointed. The empty remains are abandoned where they lie.

So must have perished the Gold Beetles, always males, whose relics I find from time to time in the cage; thus the survivors too must perish. Between the middle of June and the first of August, the inmates, numbering twenty-five at the outset, are reduced to five females. All the twenty males have disappeared, ripped open and drained dry. And by whom? Apparently by the females.

This is borne out by the two assaults which chance permitted me to witness; twice, in broad daylight, I saw the female devour the male after opening his belly under the wing-cases, or at least trying to do so. As for the rest of the murders, though direct observation be lacking, I have one very valuable piece of evidence. As we have seen, the captive does not retaliate, does not defend himself; he merely strives to escape by pulling as hard as he can.

If it were a simple fight, an ordinary scuffle such as life’s rivalries may lead to, the Beetle attacked would obviously turn round, since he is in a position to do so; in a close tussle, he would retort on the aggressor and give bite for bite. His strength enables him to wage a battle which might turn to his advantage; and the fool allows his rump to be gnawed with impunity. It looks as though an invincible repugnance prevents him from retaliating by eating a bit of her who is eating him.

This tolerance reminds me of the Languedocian Scorpion,1 who, after his wedding, allows himself to be devoured by his mate without using his weapon, the poisoned sting which is quite capable of killing the virago; it reminds me of the Praying Mantis’ swain, who is sometimes reduced to a mere stump and, in spite of all, continues his unfinished work while he is being chewed in little mouthfuls, without the least expression of revolt.2 These are nuptial rites against which the male is not entitled to protest.

The males in my collection of Gold Beetles, from the first to the last eviscerated, tell us of similar habits. They are the victims of their mates when these have had their fill of matrimony. During four months, from April to July, couples form daily, sometimes only tentatively, sometimes and more often concluding in effective pairing. There is no end to it with these fiery temperaments.

The Carabus is expeditious in his love-affairs. A male passing in the crowd flings himself upon a female, the first that comes, without any previous flirting. The she thus bestridden lifts her head a little as a sign of acquiesence, while her rider whips her neck with the tips of his antennæ. When the coupling is finished—and it does not take long—the two separate abruptly, recuperate their strength by a mouthful of the Snail served up for their food, after which they both get married again, the wedding being repeated so long as males remain available. After feasting, a brutal wooing; after the wooing, more feasting: this sums up the Gold Beetle’s life.

The ladies in my menagerie were not in proportion to the number of suitors: there were five females to twenty males. No matter: there was no rivalry, no exchange of blows; a most peaceful use and abuse was made of the passing fair. With this mutual tolerance, sooner or later, many times over and according to the chance of the encounters, each one finds the wherewithal to satisfy his ardour.

I should have preferred a more evenly divided assembly. Luck, not choice, gave me that which I had at my disposal. I collected in early spring all the Gold Beetles that I could find under the stones around, without distinction of sex, which is not easy to recognize merely by external characteristics. Afterwards, as I reared them in my cages, I learnt that a slight excess in size was the distinctive sign of the females. My menagerie, so unequal in the numerical relation of the sexes, was therefore a fortuitous result. It seems likely that this proportion of males does not exist under natural conditions.

On the other hand, such numerous groups are never seen at liberty, sheltered under the same stone. The Gold Beetle leads an almost solitary life; it is rare to find two or three gathered at one spot. The assembly in my menagerie is therefore exceptional, although it does not lead to disorder. There is plenty of room in the glass cage for distant rambles and for all the usual diversions. He who wants to be alone remains alone; he who wants company soon finds it.

For that matter, captivity does not seem to trouble them unduly, as is shown by the frequent feasting and their daily repeated mating. They could thrive no better if at liberty in the fields: perhaps they would not thrive so well, for food is not so abundant there as in the cage. As regards comfort, therefore, the prisoners are in a normal condition favouring the preservation of their usual habits.

Only, meetings of kinsfolk occur more often here than in the open. This, no doubt, affords the females better opportunities to persecute the males for whom they have no further use, to grab them by the rump and disembowel them. This hunting of the bygone lovers is aggravated but certainly not innovated by the too close vicinity: such customs are never improvised.

When the mating is over, a female meeting a male in the open must then treat him as fair game and munch him up in order to close the matrimonial rites. I have turned over many stones but have never chanced upon this spectacle; no matter: what I saw in the cage is enough to convince me. What a world the Gold Beetle lives in, where the matron devours her partner when she no longer needs him to fertilize her ovaries! And how lightly do the laws of creation hold the males, to allow them to be butchered in this way!

Are these fits of cannibalism following upon love widely distributed? For the moment I know only three really characteristic examples: those of the Praying Mantis, the Languedocian Scorpion and the Golden Carabus. The horror of the lover converted into prey is also found in the Locustian tribe, though accompanied by less brutality, for the victim devoured is now a dead and not a living insect. The female of the White-faced Decticus3 is quite willing to nibble a leg of the defunct male. The Green Grasshopper4 behaves likewise.

To a certain degree the nature of the diet acts as an excuse: Dectici and Grasshoppers are first and foremost carnivores. Coming upon a corpse of their own species, the matrons consume it more or less thoroughly, even if it be that of last night’s lover. Considered as game, one is as good as another.

But what shall we say of the vegetarians? As the laying-season approaches, the Ephippiger turns upon her companion, still full of life, and bites him, makes a hole in his belly and eats as much of him as her appetite allows. The easy-going Cricket suddenly develops a shrewish character: she beats the mate who lately wooed her in such impassioned serenades; she rends his wings, breaks his fiddle and even goes so far as to tear a few mouthfuls from the musician.5 So it seems probable that this mortal aversion of the female for the male after the pairing is fairly common, especially among the carnivorous insects. What is the reason of these atrocious habits? If circumstances favour me, I shall not fail to investigate it.

Of the whole colony in the cage I have five females left at the beginning of August. Their conduct has changed greatly since the eating of the males. Food has become indifferent to them. They no longer run up to the Snail, whom I serve half-stripped of his shell; they scorn the plump Mantis and the Caterpillar, their erstwhile delights; they doze under the shelter of the board and rarely show themselves. Can this mean preparation for the laying? I enquire into this day by day, being most anxious to see the first appearance of the little larvæ, an artless first appearance, deprived of all solicitude, as I foresee from the lack of industry in the mother.

I wait in vain: there is no laying. Meanwhile the cool nights of October arrive. Four females perish, this time by a natural death.

The survivor takes no notice of them. She refuses them burial in her stomach, a burial at one time accorded to the males, dissected alive. She cowers as deep down in the ground as the scanty earth of the cage permits. In November, when Mont Ventoux is white with the first snows, she grows torpid in her hiding-place. Let us henceforth leave her in peace. She will live through the winter, everything seems to tell us, and produce her eggs next spring.