THE MASKED BUG

I met with this insect unexpectedly and in circumstances that hardly seemed to promise an interesting discovery. A certain enquiry into the spoilers of dead meat, an enquiry set forth elsewhere,1 had brought me to the village butcher’s. What will not one do in the hope of securing an idea! The hunt after this rare quarry led me to the workshop of the slaughterer, an excellent man, for that matter, who did me the honours of his establishment to the best of his ability.

I wanted to see not the actual shop, so hateful to look upon, but the shed or what not in which the offal was collected. The butcher took me to the garret, dimly lit by a dormer-window which was left open night and day, in all weathers, to air the place. Continuous ventilation was not unwelcome [217]in that nauseous atmosphere, above all at the hottest time of year, when my visit was paid. The mere recollection of that garret is revolting to my senses.

Here, on a stretched cord, some blood-stained sheepskins are drying; in one corner is a heap of stinking tallow, in another are bones, horns and hoofs. These rags and tatters of death answer my purpose capitally. Under the shovelfuls of fat which I turn over, the Dermestes and her grub are swarming by the thousand; Clothes-moths flit indolently to and fro; and Flies with big red eyes keep on buzzing in and out of the hollow bones that still hold a little marrow. I expected this population, the habitual inmates of carrion refuse. But here is one which I did not anticipate: On the whitewashed wall are certain black patches of unsightly insects, gathered in motionless groups. Among them I recognize the Masked Bug, or Masked Reduvius (R. personatus, lin.), a large Bug of some celebrity. There are nearly a hundred of them, divided into separate flocks.

The butcher watches me as I capture my discovery and put it into a box, and is surprised [218]to see me fearlessly handling the repulsive creature. It is more than he would ever venture to do.

“It comes and plasters itself against the wall,” he tells me, “and there it stays. If I sweep it off, next day it’s back, as sure as fate. I don’t say it does any harm. It doesn’t spoil my hides, it doesn’t touch my fats. What does it come here for every summer? I don’t know.”

“I don’t know either,” I reply, “but I shall try to find out; and, when I know, I can tell you about it, if you’d like me to. It may have something to do with the preservation of your hides. We shall see.”

Behold me then, as I leave this offal-store, the shepherd of a chance-met flock. They are not much to look at. Covered with dust, black as pitch, flat, like the true Bugs that they are, standing awkwardly high on their legs, lanky and skinny: no, they do not inspire confidence. The head is so small that there is only just room for the eyes, reticulated domes whose great prominence seems to indicate good powers of vision by night. It is set on an absurd neck which looks as though it had been strangled [219]with a bow-string. The corselet is jet-black, with burnished prominences.

Let us turn it over. The beak is monstrous. Its base covers all of the face that is not occupied by the eyes. It is not the usual rostrum, the drill of the sap-sucking Hemiptera; it is a rude implement, an elbowed tool, crooked like a bent forefinger. What can the creature do with this barbarous weapon? When it is feeding I see a black thread, as fine as a hair, issuing from the beak. This is the slender scalpel: the rest is the sheath and the stout handle. This rude equipment tells us that the Reduvius is an executioner.

What sort of exploits can we expect from it? Stabbing and murdering: actions of little interest, because of their frequency. But we must make a considerable allowance for the unexpected; interesting details sometimes lie dormant and spring up suddenly amid squalid surroundings. Perhaps the Reduvius has in store for us facts worthy of record. Let us try to rear him.

His weapon, a stout yataghan, tells us that the Reduvius is a murderer. What victim does he require? This is the rearing [220]problem before us. It so happens that some time ago I saw the dingy-looking Bug at grips with the smallest of our Cetoniæ, so well-named the Pall-bearing Cetonia,2 because of her white spots on a black background. This accidental observation sets me on the right track. I house my flock in a large glass jar with a bed of sand, and as food I serve up the Cetonia aforesaid, which is common in spring on the flowers in the enclosure, but scarce at this time of year. The victim is very readily accepted. Next day I find her dead. One of the Reduvii, with his probe implanted in the joint of the neck, is working at the corpse and draining it dry.

In the absence of Cetoniæ I fall back upon any sort of game suited to the size of my boarders; and I find that any sort answers my purpose, irrespective of the different entomological orders. The usual dish, because it is the easiest for me to capture, consists of Locusts of medium size, though they are sometimes larger than the consumer. Often, too, for the same reason that he is easily obtained, it includes a Forest Bug, [221]Pentatoma nigricorna. In short, my charges’ diet does not give me much trouble: anything will do, provided that the prey does not exceed the powers of the assailant.

I was anxious to witness the attack, but I never managed to do so. As the big, prominent eyes of the Reduvius warned me, it takes place at night, at unseasonable hours. However early my inspection, I find the game lifeless, bereft of all power of movement. The hunter is feasting upon his prey and lingers over it for some part of the morning. Then, after many different applications of the probe, now at one point and now at another, when the victims are completely drained of moisture, the blood-suckers abandon the dead bodies, gather into a flock, and do not move all day long, lying flat on the sand at the bottom of the jar. On the following night, if I renew the victuals, the same massacres are repeated.

When the prey is a non-armoured insect, a Locust, for example, I have sometimes noted pulsations in the victim’s abdomen. Death, therefore, is not sudden and overwhelming; nevertheless, the quarry must be very quickly made incapable of resistance.[222]

I have confronted the Reduvius with a big-jawed Decticus, a Platycleis3 five or six times the size of his executioner. Next day the colossus was sucked dry by the dwarf as quickly as a Fly would have been. A terrible stab had paralysed him. Where was the blow delivered and how did it take effect?

There is nothing to tell us that the Reduvius is a bravo versed in the art of murder, acquainted, like the Paralysing Wasps, with the anatomy of his victims and the secrets of their nerve-centres. No doubt he drives his stiletto at random into any part where the skin is soft enough. He kills by injecting venom. His rostrum is a poisoned dagger, like that of the Gnat, but much more virulent.

It is said, indeed, that the Masked Bug’s bite is painful. Wishing myself to test its effects, so that I might speak with authority, I have tried, but in vain, to get myself bitten. When placed on my finger and pestered, the insect refused to unsheath its weapon. Frequent handling of my specimens, without [223]the use of tweezers, was no more successful. On the evidence of others, then, and not from my own experience, I believe the Reduvius’ bite to be a serious matter.

It must be so, intended as it is to kill, swiftly an insect that is not always devoid of vigour. To the victim surprised when asleep it must mean the shooting pain and sudden numbness which the Wasp’s sting would produce. The blow is struck here or there, at random. It is possible that the bandit, once the wound has been inflicted, keeps his distance for a while and waits for the limbs to cease kicking before sitting down to devour the corpse. Spiders who have caught a dangerous prey in their webs are wont to take this precaution. They withdraw a little to one side and await the last convulsions of the fettered victim.

Though the details of the murder escape me, I know how the dead insect is exploited. I can witness the performance any morning, as often as I wish. The Reduvius projects from the clumsy scabbard, crooked like a fore-finger, a delicate black lancet, which is at once a probe and a suction-pump. The [224]implement is driven into any point of the victim’s body, provided that it be covered with skin. Then comes absolute immobility; the banqueter does not budge.

Meanwhile the lancets of the sucker are working, sliding one against the other, acting as a pump, imbibing the victim’s life-blood. In like fashion the Cicada drinks the sap of her tree. When she has drained one part of the bark, she moves on and sinks another well. The Reduvius does the same; he drains his prey at several points. He goes from the back of the head to the abdomen, from the abdomen to the neck, from the neck to the thorax and the joints of the legs. Everything is done economically.

I watch with interest the tactics of a Bug exploiting his Locust. Twenty times over I see him changing his point of attack and stopping for a longer or shorter time according to the wealth encountered. He ends up with a haunch, attacked at the joint. The barrel is emptied of its juices until it becomes translucent. If the quarry’s skin is diaphanous, the same degree of exhaustion may be perceived throughout the body. Thanks to the action of the infernal pump, a young [225]Praying Mantis an inch long becomes transparent as a moulted skin.

These blood-sucking appetites remind me of our Bed-bug, who makes himself so obnoxious by exploring the sleeper, selecting a convenient spot, leaving it for another and a more profitable, and again moving on, until, swollen to the size of a currant, he withdraws at the first glimmer of daylight. The Reduvius aggravates this method: he first benumbs his victim and then drains it dry. Only the legendary vampire of romance achieves a like degree of frightfulness.

Now, what was the insect-sucker doing in a butcher’s loft? He certainly did not find there the victims which I procure for him: Locusts, young Mantes, Grasshoppers, Chrysomelæ,4 all lovers of foliage and the sunlight. These passionate lovers of open-air joys would never venture into the dark and nauseating offal-store. What, then, do these black squads clinging to the wall live upon? Such a crowd needs food, and plenty of it. Where is it?[226]

In the heap of fats, of course! Here a Dermestes (D. Frischii, kugel)5 swarms promiscuously with her hairy larvæ. The supply is inexhaustible, and it is probably that the Reduvii hastened hither attracted by this abundance. Let us then change the bill of fare, let us substitute Dermestes.

I have just what is needed at my disposal without rushing off to the butcher’s for a supply. In the garden, at this moment, supported on reed tripods, there are certain aerial retting-vats in which Moles, Snakes, Lizards, Toads, Fish and so on attract interminable visits from the undertakers of the neighbourhood. The most numerous is a Dermestes, precisely the same as the one in the tallow-loft. This is the very thing I want.

I serve this Dermestes to my Reduvii, I serve him up lavishly. A frenzied massacre takes place. Every morning the sand in the jar is strewn with corpses, many of which are still lying beneath the murderer’s beak. The conclusion is obvious: the Reduvius kills the Dermestes whenever the opportunity [227]occurs; without having an exclusive taste for this sort of game, he bleeds it, more or less eagerly, when he comes across it.

I shall communicate this result to the worthy fellow to whom I owe the ingredients of this story. I shall tell him:

“Leave them alone, the ugly creatures whom you see sleeping on the walls of your loft; don’t drive them away with your broom. They are doing you a service; they wage war upon the others, the Dermestes, who are so destructive to hides.”

It may well be that the abundance of Dermestes, an easy prey, was not the motive which attracted the Reduvii to the butcher’s garret. Elsewhere, out of doors, there is no lack of game, in great variety and no less appreciated. Why do the Bugs prefer to gather here? I suspect that they wish to establish a family. The laying-season cannot be far away; and the Reduvius has come with the particular object of providing food and lodging for her offspring. In fact, at the end of June I obtain the first eggs in my jars. For a fortnight the Bugs continue to lay abundantly. A few mothers, reared [228]separately, enable me to estimate their fecundity. I count up thirty to forty eggs for each mother.

Here we no longer see the orderliness dear to the Forest-bugs, who arrange their eggs on a leaf so methodically, in rows of beads. Far from representing an extremely accurate piece of work, the Masked Bug’s batch of eggs is strewn, clumsily, at random. The eggs are isolated, adhering neither to one another nor to their support. In my rearing-jars they are scattered over the surface of the sand. Granular specks of which the mother has taken no care whatever, not even troubling to fasten them anywhere, they roll hither and thither, at the least breath of air. A plant is not more heedless of its seeds, which go where the wind blows them.

These greatly neglected eggs are nevertheless not without beauty of form; they are oval, amber-red, smooth and glossy and about a millimetre6 in length. Near one of the ends there is a fine, dark, circular line, marking a sort of cap. The Forest-bug’s egg has taught us the meaning of this circle. [229]It is the line along which the lid of the casket will open. We have before us for the second time the tiny miracle of an egg shaped like a casket, which, on hatching, opens without breaking, by the fall of a little lid which is thrust back by the tiny creature in the act of birth.

If I can manage to see how the moveable cap is lifted, I shall obtain the most interesting detail of the Masked Bug’s history; I shall have the equivalent of the young Forest-bug bursting the ceiling of his shell by means of a sharp-angled mitre actuated by the hydraulic pulsations of the head. Let us stint neither time nor patience: the exodus of a Bug from his egg is a most notable sight.

If the problem has its attractive side, it also presents difficulties. You have to be on the spot just at the very moment when the lid gives way, which entails a wearisome vigilance. You also want plenty of light; and it must be daylight, or the refinements of this very delicate operation would escape us. The habits of the Reduvius give me cause to fear that the eggs may be hatched at night: [And the future will teach me [230]only too well how fully my fears are founded.] No matter: we will not give in. Perhaps fortune will smile upon me. And, lens in hand, for a fortnight, at all hours, from morning to night, I keep watch over a hundred eggs which I have divided among several glass tubes.

In the Forest-bug’s egg the approach of hatching is announced by a black line in the form of a broad arrow, or reversed anchor, which appears not far from the lid and is no other than the liberating mechanism. The tiny beast covers its head with its pointed mitre. Here there is nothing of the sort. From first to last, the Masked Bug’s egg retains its uniform amber colouring, without any sign of an inner lock.

Meanwhile, by the middle of July, the hatchings are becoming numerous. Every morning I find in my tubes a collection of tiny open pots, unbroken and amber-coloured as at the beginning. The lid, a concave dome of exquisite accuracy, is lying on the sand beside the empty egg-shell; sometimes it remains hanging from the edge of the orifice. The young Bugs, pretty little snow-white creatures, are gambolling nimbly [231]amidst the untenanted pots. I always come too late; what I wanted to see by sunlight is over.

As I suspected, the opening of the lid is effected in the darkness of the night. Alas, for want of sufficient light the solution of the problem which interests me so greatly will escape me! The Reduvius will keep her secret; I shall see nothing.… But yes, I do see something; for perseverance has unexpected resources. A week full of failures has already gone by, when, unexpectedly, in the brilliant light of nine o’clock in the morning, a few late-comers suddenly begin to open their boxes. Had the house caught fire just then, I doubt whether I should have stirred a limb. The sight held me rooted to the floor. Let the reader judge for himself.

Unprovided with the thread-like rivets employed by the Pentatoma, the Reduvius’ lid adheres to the shell by its mere position and a perfect fit. I see it lifting at one side and hinging on the other with a slowness that defies the magnifying powers of the lens. What is happening in the egg seems to be a long and laborious process. But the [232]lid opens wider; and through the chink I see something glistening. This is an iridescent pellicle, which protrudes, and, as it does so, pushes back the lid. Now a spherical blister emerges from the shell, gradually growing larger, like a soap-bubble blown from a straw. Pushed farther and farther back by the expansion of this bladder, the lid falls off.

Then the bomb explodes: that is to say, the capsule, inflated beyond the limits of its resistance, bursts open at the top. This envelope, an extremely thin membrane, usually adheres to the edge of the orifice, where it forms a high white rim. At other times the explosion detaches it and shoots it out of the shell. Under these conditions it is a delicate goblet, hemispherical, with torn edges, and with its lower part continued by a fine, twisted stem.

It is finished; the thoroughfare is open. The tiny insect can now emerge by bursting through the pellicle caught in the opening, or by dislodging it; or it may find an absolutely free passage, when the burst bladder has left the egg. It is all simply miraculous. To escape from his box, the Pentatoma invented [233]the three-ribbed mitre and the hydraulic ram; the Reduvius has invented the explosive bomb. The first goes to work gently; the second, a brutal dynamiter, blows the roof off his prison with a bomb.

With what explosive, and how is the liberating shell loaded? At the moment of rupture nothing visible bursts from the bubble; nothing liquid moistens the torn edge. The contents, therefore, were assuredly gaseous. The rest escapes me. One observation, which I was unable to repeat, is not enough in this delicate matter. Reducing it to mere probabilities I will propose the following explanation:

The tiny animal is wrapped in a tightly closed tunic which embraces it snugly. This is a temporary skin, a sheath which the new-born larva will shed on leaving the egg. This sheath is connected with an appendage, a capsule placed under the lid. The twisted stem hanging from the burst bubble when it is shot out of the egg represents the communicating duct.

Very slowly, as the little creature takes shape and grows, this bladder-like reservoir receives the products of the respiration [234]which takes place under the cover of the tunic or “overall.” Instead of dispersing outside, through the egg-shell, the carbonic acid gas incessantly resulting from the vital process of oxidization accumulates in this sort of gasometer, filling and distending it and pressing upon the lid. When the little Bug is mature and on the point of hatching, the increased activity of its respiration completes the inflation, which has doubtless been proceeding ever since the earliest development of the germ. At last, yielding to the increasing pressure of the gas-filled capsule, the lid becomes unfastened. The Chick in its shell has its air-chamber: the young Reduvius has its bomb of carbonic acid gas: it releases itself by breathing.

The singular hatching-processes of the Pentatoma and the Reduvius are obviously not isolated cases. The egg with a removable lid must be employed by other Hemiptera; it may even be that this is a fairly general device. Each genus has its own methods of opening its box, its own system of springs and levers. What a mechanism to find in the egg of a Bug, and how fertile [235]in surprises! What an interesting harvest to be reaped, with patience and a good pair of eyes!

Let us now watch the little Reduvius’ emergence. The lid fell off a few moments ago. The tiny insect, white all over, comes forth, tightly swaddled. The tip of its abdomen still remains within the opening, which, with its rim of skin, the remnant of the bomb, serves it as a supporting girdle. It struggles, swaying to and fro and leaning backwards. This gymnastic exercise, increasing the creature’s flexibility, is intended to undo the swaddling-clothes at the seams. Sleeves, breeches, gaiters, shirt-front, cap: little by little the whole is torn off, not without effort on the fettered pigmy’s part; it is all cast aside and disappears in tatters. Behold the new-born insect at liberty! It skips away to some distance from the egg. With its long, fine, waving antennæ it interrogates space, enquiring into this mighty world. Often, when the lid still adheres to some point of the opening, it carries this bit away with it, on its back or its rump. You would think it was going to the wars, bearing the umbo of antiquity, the round, [236]convex buckler. What does it want with this armour? Has it seized upon it as a means of defence? Not at all. The cover of the beaker happened to come into contact with it and at once stuck to it, even firmly, for nothing short of the approaching moult will detach the disk. This detail tells us that the little creature exudes a fluid capable of acting as an adhesive in respect of any light objects encountered on its passage—with what results we shall presently see.

With shield on back or without this panoply, standing high on its legs and sporting a long pair of horns, the new-born insect crosses the threshold of the egg; it roams about in sudden fits and starts, presenting the appearance of a minute Spider. Two days later, before taking any food, it undergoes a moult. The gormandizer, once he has eaten his fill, undoes a button to make room for the belated dainties concluding the meal. The Bug, who has as yet eaten nothing, splits his coat from top to bottom, throws it away, and puts on a new skin. He even changes his belly before sitting down to table. He used to wear a short, stumpy abdomen; he now has a plump, round [237]paunch. The time has come for feasting.

A restaurant-keeper with no experience of the proper bill of fare, what shall I provide? I remember a passage in Linnæus7 touching the Reduvius. The master says:

“Consumit cimices lectularios huius larva, horrida, personata.” “Its horrid, masked larva sucks the Bed-bugs.”

This game seems to me out of proportion for the moment: the little creatures in my jars, weak and tiny as they are, would never dare to tackle such a quarry. There is another objection: the moment I want Bugs, I am unlikely to find any. Let us try something else.

The adult has eclectic tastes; it hunts the most varied prey. The larva might well do likewise. I offer Midges. They are absolutely refused. In the garret whence my flock originated, what could they have found that was easily obtained, without scuffling, so dangerous at that tender age? They would have found tallow, bones, hides, and nothing else. Let us give them tallow.

This time all goes well. My little creatures [238]settle down on the fatty substance, driving their suckers into it, drinking deeply of the stinking olein, and then retire to digest their meal in the sand, wherever they please. They thrive. I see them growing from day to day. In a fortnight they are plump, and, what is more, disguised beyond recognition. Their whole bodies, including the legs, are encrusted with sand.

This mineral bark began to form directly after the moult. The little creatures became speckled with earthy particles, thinly scattered at random. At present the envelope is continuous. Let matters take their course, and this wrap will become a sordid overall. Then the larva will really deserve the epithets which Linnæus bestows upon it: horrida, personata, the horrible insect that dons a mask and wears a dusty domino.

Should it occur to us to regard this tatter-demalion costume as an intentional piece of work, a ruse de guerre, a means of dissimulation whereby to approach its prey, we may undeceive ourselves: the Reduvius does not industriously make itself an overcoat; nor does it wear one with the object of concealing [239]itself. It all happens of itself, without any sort of art, like the mechanism whose secret was revealed to us by the lid of the egg, worn as a buckler. The insect exudes a certain unctuous humour, derived perhaps from the tallow on which it feeds. To this varnish, the dust through which it passes adheres without any further trouble on the insect’s part. The Reduvius does not dress itself; it dirties itself; it turns into a pellet of dust, a walking bit of filth, because it emits a sticky sweat.

One word more as to its diet. Linnæus, obtaining his information I know not where, makes the Reduvius our auxiliary against the Bed-bug. Since then, the books, monotonously echoing one another, have repeated the eulogy; it is accepted as a tradition that the Masked Reduvius makes war upon our nocturnal bloodsucker. This would certainly constitute a magnificent claim on our gratitude. But is it really the truth? I take the liberty of rebelling against tradition. That the Reduvius is sometimes found slaying Bed-bugs is very likely: my own captives were satisfied with Forest-bugs. They accepted them, however, without clamouring [240]for them; and they readily dispensed with them, seeming to prefer Locusts or any other insects.

Let us not then hasten to generalize and to look upon the Reduvius as a licensed consumer of the stinking pest of our beds. I see an important objection to this special vocation. Comparatively large in size, the Reduvius could not slip into the narrow chinks that shelter the Bed-bug. A fortiori, to track the Bed-bug to its lair is impracticable for the larva, hampered by its overcoat of dust, unless it invade our beds at the time when the other is running over us and selecting its morsel. Nothing justifies our presuming this intimacy with the sleeper; no one, that I know of, has surprised the Reduvius or its larva in the act of investigating our beds.

The masked larva does not deserve to be extolled for a few accidental captures. Its diet is quite different from what Linnæus tells us and the compilers keep on repeating. In its infancy it feeds on fatty matters, as my rearing-experiments prove. When it grows big it varies its victuals with insects, of no matter what order, as does the adult. [241]For it a butcher’s garret is an abode of bliss, where it finds a supply of fats, and, later, Flesh-flies, Dermestes, and other insects that batten on dead things. In the dark and ill-swept corners of our houses it gleans the particles of fat that fall from our kitchen-table; it catches unawares the drowsy Fly, the small, homeless Spider. This is enough to ensure its welfare.

Here is one more tradition to be deleted from our books, without much injury, however, to the insect’s reputation. If the Masked Bug ceases to appear in history as the executioner of the Bed-bug, it will henceforth cut a more respectable figure as the inventor of the box that is opened by the explosion of a bomb.