Insect Adventures 3

	Insect Adventures 3

“Among your kitchen utensils,” I said, “you have a pot in daily use; but it has lost its lid, which was knocked over and broken by the cat playing on the shelves. To-morrow is market-day and one of you will be going to Orange to buy the week’s provisions. Would she undertake, without a measure of any kind, with the sole aid of memory, which we would allow her to refresh by a careful examination of the object before starting, to bring back exactly what the pot wants, a lid neither too large nor too small, in short, the same size as the top?” It was admitted with one accord that nobody would accept such a commission without taking a measure with her, or at least a bit of string giving the width. Our memory for sizes is not accurate enough. She would come back from the town with something that “might do”; and it would be the merest chance if this turned out to be the right size. [Illustration: “What pattern that she carries in her mind guides her scissors?”] Well, the Leaf-cutting Bee is even less well off than ourselves. She has no mental picture of her pot, because she has never seen it; she is not able to pick and choose in the crockery dealer’s heap, which acts as something of a guide to our memory by comparison; she must, without hesitation, far away from her home, cut out a disk that fits the top of her jar. What is impossible to us is child’s play to her. Where we could not do without a measure of some kind, a bit of string, a pattern or a scrap of paper with figures upon it, the little Bee needs nothing at all. In housekeeping matters she is cleverer than we are. The insect excels us in practical geometry. I look upon the Leaf-cutter’s pot and lid as an addition to the many other marvels of instinct that cannot be explained by mechanics; I submit it to the consideration of science; and I pass on. [Illustration] CHAPTER VII THE COTTON-BEES AND RESIN-BEES There are many Bees who, like the Leaf-cutters, do not make their own dwellings, but use shelters made by the work of others. Many of the Osmia-bees seize the old homes of the Masons; other honey-gatherers use earthworm galleries, snail-shells, dry brambles which have been made into hollow tubes by the mining Bees, and even the homes of the Digger Wasps burrowed in the sand. Among these borrowers are the Cotton-bees, who fill the reeds with cottony satchels, and the Resin-bees, who plug up snail-shells with gum and resin. There is a reason for such arrangement. The Bees who work hard to make their homes, such as the Mason-bee, who scrapes hard clay and makes a large cement mansion, the Carpenter-bee, who bores dead wood to a depth of nine inches, and the Anthophora, who digs corridors and cells in the banks hardened by the sun, have no time left to spend in furnishing their cells elaborately. On the other hand, the Bees who take possession of ready-made homes, are artists in interior decorations. There is the Leaf-cutting Bee, who makes her leafy baskets with such skill; the Upholsterer-bee, who hangs her cells with poppy-petals, and the Cotton-bee, who makes the most beautiful purses of cotton. We have only to look at the Cotton-bee’s nests, to realize that the insect who makes these could not be a digger, too. When newly-felted, and not yet sticky with honey, the wadded purse is very elegant, of a dazzling white. No bird’s-nest can compare with it in fineness of material or in gracefulness of form. How, with the little bales of cotton brought up one by one in her mouth, can the Bee manage to mat all together into one material and then to work this into a thimble-shaped wallet? She has no other tools to work with than those owned by the Mason-bees and the Leaf-cutting Bees; namely, her jaws and her feet. Yet what very different results are obtained! It is hard to see the Cotton-bees in action, since they work inside the reeds when making the nests. However, I will describe the little that I saw. The Bee procures her cotton from many different kinds of plants, such as thistles, mulleins, the woolly sage and everlastings. She uses only the plants that are dead and dry, however, never fresh ones. In this way she avoids mildew, which would make its appearance in her nests in the mass of hairs still filled with sap. [Illustration] She alights on the plant she wishes to use, scrapes it with her mouth, and then passes the tiny flake to her hind-legs, which hold it pressed against the chest, mixes with it still more down, and makes the whole into a little ball. When this is the size of a pea, it goes back to the mouth, and the insect flies off, with her bale of cotton in her mouth. If we have the patience to wait, we shall see her coming back again and again to the same plant, until her bags are all made. The Cotton-bee uses different grades of cotton for the different parts of her work. She is like the bird, who furnishes the inside of her nest with wool to make it soft for the little birds, and strengthens the outside with sticks. The Bee makes her cells, the grubs’ nurseries, of the very finest down, the cotton gathered from a thistle; she makes the barrier plug at the entrance of stiff, prickly hairs, such as the coarse bristles scraped from a mullein-leaf. I do not see her making the cells inside the bramble, but I catch her preparing the plug for the top. With her fore-legs she tears the cotton apart and spreads it out; with her jaws she loosens the hard lumps; with her forehead she presses each new layer of the plug upon the one below. This is a rough task; but probably her general way of working is the same for the finer cells. Some Cotton-bees after making the plug go even further and fill up the empty space at the end of the bramble with any kind of rubbish that they can find: little pieces of gravel, bits of earth, grains of sawdust, mortar, cypress-catkins, or broken leaves. The pile is a real barricade, and will keep any foe from breaking in. The honey with which the Cotton-bee whose nest I examined filled the cells was pale-yellow, all of the same kind and only partly liquefied, so that it would not trickle through the cotton bag. On this honey the egg is laid. After a while the grub is hatched and finds its food all ready. It plunges its head in the honey, drinks long draughts, and grows fat. We will leave it there, knowing that after a while it will build a cocoon and turn into a Cotton-bee. Another interesting Bee who uses a ready-made home is the Resin-bee. In the stone-heaps which have been left from the quarries, we often find the Field-mouse sitting on a grass mattress, nibbling acorns, almonds, olive-stones, apricot-stones, and snail-shells. When he is gone, he has left behind him, under the overhanging stones, a heap of empty shells. Among these, there is always a hope of finding a few plugged up with resin, the nests of this sort of Bee. The Osmia-bees also use snail-shells, but they plug them up with clay. [Illustration] It is hard to tell the Resin-bees’ nests, because the insect often makes its home at the very inside of the spiral, a long way from the mouth. I hold up a shell to the light. If it is quite transparent, I know that it is empty and I put it back to be used for future nests. If the second whorl is opaque, does not let the light through, the spiral contains something. What? Earth washed in by the rain? Remnants of the dead Snail? That remains to be seen. With a little pocket-trowel I make a wide window in the middle of the final whorl. If I see a gleaming resin floor, with incrustations of gravel, the thing is settled: I have a Resin-bee’s nest. [Illustration] The Bee picks out the particular whorl of the shell which is the right size for her nest. In large shells, the nest is near the back; in smaller shells, at the very front, where the passage is widest. She always makes a partition of a mosaic formed of bits of gravel set in gum. I did not know at first what this gum was. It is amber-colored, semi-transparent, brittle, soluble in spirits of wine, and burns with a sooty flame and a strong smell of resin. These characteristics told me that the Bee uses the resinous drops that ooze from the trunks of various cone-bearing trees. There are plenty of junipers in the neighborhood, and I think that these form the main part of this Bee’s materials. If there were pines, cypresses, and other cone-bearing trees near, she would probably use those. After the lid of resin and gravel, the Bee stops up the shell still further with bits of gravel, catkins and needles of the juniper, and other odds and ends, including a few rare little land-shells. This is the secondary barrier, to make the shell still safer for her nest. The Cotton-bee uses the same sort of barrier in the bramble. The Resin-bee uses it only in the larger shells, where there is much vacant space; in the smaller ones, where her nest reaches nearly to the entrance, she does without it. The cells come next, farther back in the spiral. There are usually only two. The front room, which is the larger, contains a male, which in this kind of Bee is larger than the female; the smaller back room houses a female. It is extraordinary how the mother Bee knows the sex of the egg she is laying. This matter has never been explained to the satisfaction of scientists. The Resin-bee makes a mistake in choosing large shells and not filling them up to the very entrance. The Osmia-bee also makes her nest in snail-shells; she often seizes upon the empty rooms in the Resin-bee’s house and fills them with her mass of cells. She then stops up the entrance with a thick clay stopper. When July comes, this house with the two families of tenants becomes the scene of a tragic conflict. The Resin-bees, in the back rooms, on attaining the adult state, burst their swaddling bands, bore their way through the resin partitions, pass through the gravel barricade and try to release themselves. Alas, the strange family ahead blocks the way! The Osmia inmates are still in the grub stage; they mean to stay in their cells till the next spring. The Resin-bees cannot get out through this second row of clay-stoppered cells; they give up all hope and perish behind the wall of earth. If their mother had only foreseen this danger, the disaster would never have happened; but instinct has failed her for once. Misfortune has not taught the Resin-bees anything through all the generations; and this contradicts the theory of those scientists who say that animals learn through experience. [Illustration] CHAPTER VIII THE HAIRY SAND-WASPS A slender waist, a slim shape; an abdomen tapering very much at the upper part and fastened to the body as though by a thread; black raiment with a red sash across the belly: there you have a short description of the burrowing Sand-Wasps, who hunt Caterpillars. The Sand-Wasps choose for their burrows a light soil, easily tunneled, in which the sand is held together with a little clay and lime. Edges of paths, sunny banks where the grass is rather bare—these are the favorite spots. In spring, quite early in April, we see the Hairy Sand-Wasp there. Its burrow is a straight up-and-down hole, like a well, about as thick as a goose-quill and about two inches deep. At the bottom is a solitary cell, to hold the egg. The Sand-Wasp digs by herself, quietly, without hurrying, without any joyous enthusiasm. As usual, the front feet serve as rakes and the jaws do duty as mining-tools. When some grain of sand is very hard to remove, you hear rising from the well a sort of shrill grating sound made by the quivering of the insect’s wings and of her whole body. Every little while the Wasp appears in the open with a load of dirt in her teeth, some bit of gravel which she usually flies away with and drops at a distance of a few inches, so as not to litter the place. Some of these grains the Sand-Wasp does not treat as she does the rest. Instead of flying off and dropping them far from the work yard, she removes them on foot and lays them near her burrow. She has a special use for them. When her home is dug, she looks at this little heap of stones to see if there is any there to suit her. If there is not, she explores the neighborhood until she finds what she wants, a small flat stone a little larger in diameter than the mouth of her hole. She carries off this slab in her jaws and lays it, as a temporary door, over the opening of the burrow. To-morrow, when she comes back from hunting, the Wasp will know how to find her home, made safe by this heavy door; she will bring back a paralyzed caterpillar, grasped by the skin of its neck and dragged between her legs; she will lift the slab, which looks exactly like the other little stones around, and which she alone is able to identify; she will let down the game to the bottom of her well, lay her egg and close the house for good by sweeping into the hole all the rubbish, which she has kept near by. The Hairy Sand-Wasp hunts a particular sort of prey, a kind of large Caterpillar called the Gray Worm, which spends most of its time underground. How does she then get hold of it? We shall see. One day I was returning from a walk when I saw a Hairy Sand-Wasp very busy at the foot of a tuft of thyme. I at once lay down on the ground, close to where she was working. My presence did not frighten the Wasp; in fact, she came and settled on my sleeve for a moment, decided that her visitor was harmless, since he did not move, and returned to her tuft of thyme. As an old stager, I knew what this tameness meant: the Wasp was too busy to bother about me. [Illustration] The insect scratched the ground at the foot of the plant, where the root joined the stem, pulled up slender grass rootlets and poked her head under the little clods which she had lifted. She ran hurriedly this way and that around the thyme, looking at every crevice. She was not digging herself a burrow but hunting the game hidden underground; she was like a Dog trying to dig a Rabbit out of his hole. Presently, excited by what was happening overhead, a big Gray Worm made up his mind to leave his lair and come up to the light of day. That settled him: the Wasp was on the spot at once, gripping him by the skin of his neck and holding tight in spite of his contortions. Perched on the monster’s back, the Wasp bent her abdomen and deliberately, without hurrying, like a clever surgeon, drove her lancet-sting into the back surface of each of the victim’s rings or segments, from the first to the last. Not a ring was left without receiving a stab; all, whether with legs or without, were dealt with in order, from front to back. [Illustration] The Wasp’s skill would make science turn green with envy! She knows by instinct what man hardly ever knows; she knows her victim’s nervous system and exactly what nerve centers to strike to make it motionless without killing it. Where does she receive this knowledge? From the power that rules the world, and guides the ignorant by the laws of its inspiration. I will tell you about another encounter of a Sand-Wasp with a Gray Worm which I witnessed. It was in May, when I detected a Sand-Wasp giving a last sweep of the rake to her burrow, on the smooth, hard path. She had paralyzed her Caterpillar, probably, and left it a few yards away from the home while she made ready the entrance. At last the cave is pronounced spick and span, and the doorway thought wide enough to admit the bulky prey. The Sand-Wasp sets off in search of her captive. She finds it easily. It is a Gray Worm, lying on the ground: but, alas, the Ants have found it, too; they have already invaded it. The Wasp now scorns it. She will not have anything to do with a Worm which she must share with Ants. To drive them away is impossible; for each one sent to the right-about, ten would return to the attack. So the Wasp seems to think; for she goes on with her hunting, without indulging in useless strife. She explores the soil within a radius of ten feet from the nest, on foot, little by little, without hurrying; she lashes the ground continually with her antennæ curved like a bow. For nearly three hours, in the heat of the sun, I watch her search. What a difficult thing a Gray Worm is to find, for a Wasp who needs it just at that moment! It is no less difficult for man. I have a plan. I wish to give the Wasp a Worm in order to see how she paralyzes it. Favier, my old soldier friend, is there, gardening. I call out to him: “Come here, quick; I want some Gray Worms!” I explain the thing to him. He understands at once and goes in search. He digs at the foot of the lettuces, he scrapes among the strawberry-beds, he inspects the iris-borders. I know his sharp eyes and his intelligence; I have every confidence in him. Meanwhile, time passes. “Well, Favier? Where’s that Gray Worm?” “I can’t find one, sir.” “Bother! Then come to the rescue, you others! Claire, Aglae, all of you! Hurry up, hunt and find!” The whole family is put at work. All its members become very active. But nothing turns up: three hours pass and not one of us has found the Caterpillar. The Sand-Wasp does not find it either. I see her hunting persistently in spots where the earth is slightly cracked. She wears herself out in clearing-operations; with a great effort she removes lumps of earth the size of an apricot-stone. These spots are soon given up, however. Then a suspicion comes to me: perhaps the Gray Worm, foreseeing a gathering storm, has dug its way lower down. The huntress Wasp very well knows where it lies, but cannot get it out from its deep hiding-place. Wherever the Sand-Wasp scratches, there must a Gray Worm be; she leaves the place only because she cannot dig deep enough. It was very stupid of me not to have thought of this earlier. Would such an experienced huntress pay any attention to a place where there is really nothing? What nonsense! I make up my mind to help her. The insect, at this moment, is digging a tilled and absolutely bare spot. It leaves the place, as it has already done with so many others. I myself continue the work, with the blade of a knife. I do not find anything, either; and I leave it. The insect comes back and again begins to scratch at a certain part of my excavations. I understand: “Get out of that, you clumsy fellow!” the Wasp seems to say. “I’ll show you where the thing lives!” I dig at the spot she indicates and unearth a Gray Worm. Well done, my clever Sand-Wasp! Did I not say that you would never have raked at an empty burrow? [Illustration] Following the same system, I obtain a second Gray Worm, followed by a third and a fourth. The digging is always done at bare spots that have been turned by the pitchfork a few months earlier. There is absolutely nothing to show the presence of the Caterpillar from without. Well, Favier, Claire, Aglae, and the rest of you, what have you to say? In three hours you have not been able to dig me up a single Gray Worm, whereas this clever huntress supplies me with as many as I want, once that I have thought of coming to her assistance! THE ATTACK I leave the Wasp her fifth Worm, which she unearths with my help. I will tell in numbered paragraphs the various acts of the gorgeous drama that passes before my eyes. I am lying on the ground, close to the slaughterer, and not one detail escapes me. 1. The Sand-Wasp seizes the Caterpillar by the back of the neck with the curved pincers of her jaws. The Gray Worm struggles violently, rolling and unrolling its body. The Wasp is quite unconcerned: she stands aside and thus avoids the shocks. Her sting strikes the Caterpillar at the joint between the first ring and the head, in the middle of the under side, at a spot where the skin is more delicate. This is the most important blow, the one which will master the Gray Worm and make it more easy to handle. [Illustration: “The gorgeous drama.”] 2. The Sand-Wasp now leaves her prey. She flattens herself on the ground, with wild movements, rolling on her side, twitching and dangling her limbs, fluttering her wings, as though in danger of death. I am afraid that the huntress has received a nasty wound in the contest. I am overcome with emotion at seeing the plucky Wasp finish so piteously. But suddenly the Wasp recovers, smooths her wings, curls her antennæ, and returns briskly to the attack. What I had taken for the convulsions of approaching death was the wild enthusiasm of victory. The Wasp was congratulating herself on the way she had floored the enemy. 3. The Wasp grips the Caterpillar by the skin of the back, a little lower than before, and pricks the second ring, still on the under side. I then see her gradually going back along the Gray Worm, each time seizing the back a little lower down, clasping it with the jaws, those wide pincers, and each time driving the sting into the next ring. In this way are wounded the first three rings, with the true legs; the next two rings, which are legless; and the four rings, with the pro-legs, which are not real legs, but simply little protuberances. In all, nine stings. After the first prick of the needle, the Gray Worm offers but a feeble resistance. 4. Lastly, the Sand-Wasp, opening the forceps of her jaws to their full width, seizes the Caterpillar’s head and crunches it, squeezing it with a series of leisurely movements, without creating a wound. She pauses after each squeezing as if to learn the effect produced; she stops, waits, and begins again. This handling of the brain cannot be carried too far, or the insect would die; and strange to say, the Wasp does not wish to kill the Caterpillar. The surgeon has finished. The poor patient, the Worm, lies on the ground on its side, half doubled up. It is motionless, lifeless, unable to resist when the Wasp drags it to the burrow, unable to harm the grub that is to feed upon it. This is the purpose of the Wasp’s proceedings. She is procuring food for her babies, which are as yet non-existent. She will drag the Caterpillar to her burrow and lay an egg upon it. When the grub comes out of the egg, it will have the Caterpillar to feed upon. But suppose this Caterpillar were active? One movement of his body would crush the egg against the wall of the cell. No, the Caterpillar must be motionless; but it must not be dead, for if it were, it would speedily decay and be unfit eating for the fastidious little grub. The Wasp, therefore, drives her poisoned sting into the nerve-centers of every segment whose movement could hurt the grub-baby. She does better than that. The victim’s head is still unhurt, the jaws are at work; they might easily, as the Caterpillar is dragged to the burrow, grip some bit of straw in the ground and stop progress. The Caterpillar, therefore, must be rendered torpid, and the Wasp does this by munching his head. She does not use her sting on the brain, because that would kill the Caterpillar; she merely squeezes it enough to make the Caterpillar unconscious. Though we admire the wonderful skill of the Wasp, we cannot help feeling sorry for the victim, the poor Gray Worm. If we were farmers, however, we should not waste any pity on the Worm. These Caterpillars are a dreadful scourge to agricultural crops, as well as to garden produce. Curled in their burrows by day, they climb to the surface at night and gnaw the base or collar of plants. Everything suits them: ornamental plants and edible plants alike, flower-beds, market-gardens, and plants in fields. When a seedling withers without apparent cause, draw it to you gently; and the dying plant will come up, but maimed, cut from its root. The Gray Worm has passed that way in the night; its greedy jaws have cut the plant. It is as bad as the White Worm, the grub of the Cockchafer. When it swarms in a beet-country, the damage amounts to millions. This is the terrible enemy against which the Sand-Wasp comes to our aid. Let us not feel too sorry for it! [Illustration] CHAPTER IX THE WASP AND THE CRICKET At the end of July the Yellow-winged Wasp tears the cocoon that has protected her till then and flies out of her underground cradle. During the whole of August she is often seen flitting about the fields in search of honey. But this careless life does not last long, for by the beginning of September the Wasp must begin to dig her burrows and search for game for her family. For her burrows she usually chooses some sandy soil on the high banks by the side of the road. One thing is necessary: the site must receive plenty of sunshine. Ten or twelve Yellow-winged Wasps usually work together. They scrape the earth with their fore-feet like mischievous puppies. At the same time, each worker sings her glad song, which is a shrill noise, constantly broken off and rising higher or sinking lower in a regular rhythm. One would think they were a troop of merry companions singing to encourage each other in their work. Meanwhile, the sand flies, falling in a fine dust on their quivering wings; and the too-large gravel, removed bit by bit, rolls far away from the work yard. If a piece seems too heavy to be moved, the insect gets up steam with a shrill note which reminds one of the workman’s “Hoo!” Soon the cave takes shape; the insect dives into it bodily. We still hear underground her untiring song, while every little while we catch a glimpse of her hind-legs, pushing a torrent of sand backwards to the mouth of the burrow. From time to time the Wasp comes outside the entrance to dust herself in the sun, and to rid herself of grains of sand. In spite of these interruptions, she manages to dig the gallery in two or three hours. Then she comes to her threshold to chant her triumph and give the finishing polish to her work by smoothing out some unevenness and carrying away a speck or two of earth. There are two, three, or four cells in the Yellow-winged Wasp’s burrow, in each of which lies an egg. But the Wasp does not content herself with one burrow: she digs about ten, all in the month of September, and she has to get food for all of them. She has not a moment to lose, when, in so short a time, she has to dig her burrows, procure a dozen Crickets or more for food for her families, and stop the burrows up again. Besides, there are gray days and rainy days during the month, when she cannot work. The Yellow-winged Wasp is not content with comparatively defenseless Beetles and Caterpillars; she hunts the powerful Cricket. Watch her chasing one. The terrified Cricket takes to flight, hopping as fast as he can; the Wasp pursues him hot-foot, reaches him, rushes upon him. There follows, in the dust, a confused struggle, wherein each fighter is in turn victor and vanquished, on top and underneath. The issue seems doubtful. But at last the Wasp triumphs. In spite of his vigorous kicks, in spite of the snaps of his pincer-like jaws, the Cricket is laid low and stretched upon his back. [Illustration] The Wasp places herself upon him, belly to belly, but in the opposite direction. She grasps one of the threads at the tip of the Cricket’s abdomen with her mouth and masters with her fore-legs the convulsive efforts of his thick hinder-thighs. At the same time her middle-legs hug the heaving sides of the beaten insect, and her hind-legs force the joint of the neck to open wide. The Wasp then curves herself outward so as to offer the Cricket no chance to bite her, and drives her poisoned sting once into the victim’s neck, next into the joint of the front two rings of the thorax, or part next the neck, and lastly towards the abdomen. In less time than it takes to tell, the murder is done; and the Wasp, after making herself tidy again, gets ready to haul home the victim. You must acknowledge she knows how to fight, better even than the Wasps who attack Beetles, or those who capture Caterpillars. Those insects cannot fly, they have no defensive weapons. What a difference between them and the Cricket! The Cricket is armed with dreadful jaws, capable of eating the vitals out of the Wasp if they succeed in seizing her; he has a pair of powerful legs, regular clubs bristling with a double row of sharp spikes, which can be used by the Cricket either to hop out of his enemy’s reach, or to send her sprawling with brutal kicks. Notice, therefore, the precautions the Wasp takes before setting her sting in motion. She turns the Cricket upon his back so that he cannot use his hind-legs to escape. She controls his spurred legs with her fore-feet, so that he cannot kick her; and she keeps his jaws at a distance with her own hind-legs. She makes him motionless by grasping one of the threads at the end of the abdomen. An athlete, an expert wrestler, could not do better. Consider, also, her science. She wishes to paralyze the prey without killing it, so that it will remain in a fit condition for food for her babies for many weeks. If she should leave the Cricket any power of motion, it would knock the eggs off; if she killed it entirely, it would decay. How does she produce this paralysis? She does just what a surgeon would advise her to do; she strikes the nerve-centers of the different parts of the Cricket’s body which are likely to do harm, the three nervous centers that set the legs in motion. If we look at the Cricket a week, two weeks, or even longer after the murder, we shall see the abdomen moving slightly, a sign that he is still alive. After the Wasp has paralyzed her Cricket, she grips him with her feet, holding also one of his antennæ in her mouth, and in this manner flies off with him. She has to stop sometimes to take a minute’s rest. Then she once more takes up her burden and, with a great effort, carries him in one flight almost to her home. The Wasp I am watching alights in the middle of a Wasp village. She makes the rest of her way on foot. She bestrides her victim and advances, bearing her head proudly aloft and hauling the Cricket, who trails between her legs, by the antennæ held between her jaws. If the ground is bare, she has an easy time; but sometimes she meets with some spreading grass shoots, and then it is curious to see her marches and countermarches, her repeated attempts to get past, which she finally does by some means or other, either by flight or by taking another path. At last she reaches home and places the Cricket so that his antennæ exactly touch the mouth of the burrow. The Wasp then leaves him and goes down hastily to the bottom of the cave, perhaps to see that everything is as it should be and no other Wasp has made her nest there. A few seconds later she reappears, showing her head out of doors and giving a little cry of delight. The Cricket’s antennæ are within her reach; she seizes them, and the game is brought quickly down to the lair. When the Yellow-winged Wasp has stacked up three or four Crickets for each cell, she lays an egg on one of them and closes the burrow. She does this by sweeping the heaped-up sand outside the door down the burrow. She mixes fair-sized bits of gravel with the sand to make it stronger. If she cannot find gravel of the right size within reach, she goes and searches in the neighborhood, and seems to choose the pieces as carefully as a mason would choose the chief stones for his building. In a few moments she has closed up the underground dwelling so carefully that nothing remains to show where it has been. Then she goes on, digs another burrow, catches game for it, and walls it up. And so on. When she is through laying all her eggs, she goes back to the flowers, leading a careless, wandering life until the first cold snap puts an end to her existence, which has been so full of duties and excitements. [Illustration] CHAPTER X THE FLY-HUNTING WASP You have read about the Wasps who store up paralyzed Caterpillars and Crickets for their babies’ food, then close up the cells and fly away; now you shall hear about a Wasp who feeds her children with fresh food from day to day. This is the Bembex, or the Fly-hunting Wasp, as I shall call her. This Wasp digs her burrows in very soft, light sand, under a blazing sun and a blue sky. I go out and watch her sometimes on an unshaded plain where it is so hot that the only way to avoid sunstroke is to lie down at full length behind some sandy knoll, put one’s head down a rabbit-burrow, or provide one’s self with a large umbrella. The latter is what I did. If the reader will sit with me under the umbrella at the end of July, he will see the following sight. A Fly-hunting Wasp arrives suddenly and alights, without any hesitation, at a spot which to my eyes looks exactly like the rest of the sandy surface. With her front feet, which are armed with rows of stiff hairs and remind one at the same time of a broom, a brush, and a rake, she works at clearing her underground dwelling. The insect stands on her four hind-legs, while the front ones first scratch and then sweep the shifting sand. She shoots the sand backwards so fast that it gushes in a curve like a stream of water, falling to the ground seven or eight inches away. This spray of dust is kept up evenly for five or ten minutes at a time by the swift, graceful Wasp. Mingled with this dust are tiny bits of wood, decayed leaf stalks, particles of grit and other rubbish. The Wasp picks them up in her mouth and carries them away. This is really the purpose of her digging. She is sifting out the sand at the entrance to her home, which is all ready underground, having been dug some time before. The Wasp wishes to make the sand at the entrance to her burrow fine, light, and free from any obstacle, so that when she alights suddenly with a Fly for her children, she can dig an entrance to her home quickly. She does this work in her spare time, when her larva has enough food to last it for a while, so that she does not need to go hunting. She seems happy as she works so fast and eagerly, and who knows that she is not expressing in this way her mother’s satisfaction in watching over the roof of her house where her baby lives? If we should take a knife and dig down into the sand where the Wasp-mother is scratching, we should find, first, an entrance corridor, as wide as one’s finger, and perhaps eight to twelve inches long, and then a room, hollowed out down below where the sand is damper and firmer. It is large enough to contain two or three walnuts; but all it does hold at present is a Fly, a golden-green Greenbottle, with a tiny white egg laid on the side. This is the Wasp’s egg. It will hatch out in about twenty-four hours, into a little worm, which will feed on the dead Fly. For the Fly is dead, and not paralyzed, as the food of other Wasp-babies often is. [Illustration] At the end of two or three days the Wasp-grub will have eaten up the little Fly. Meanwhile the mother Wasp remains in the neighborhood and you see her sometimes feeding herself by sipping the honey of the field flowers, sometimes settling happily on the burning sand, no doubt watching the outside of the house. Every now and then she sifts the sand at the entrance; then she flies away for a while. But, however long she may stay away, she never forgets the young larva who has food enough to last only a short time; her mother’s instinct tells her the hour when the grub has finished its food and wants more. She therefore returns to the nest, which, you must remember, does not show in the least from the surface of the ground, as the shifting sand has filled in the entrance; she knows, however, exactly where to look for it; she goes down into the earth, this time carrying a larger piece of game. After leaving this in the underground room she again leaves the house and waits outside until the time comes to serve a third course. This is not long, for the little worm is getting a larger appetite all the time. Again the mother appears with another Fly. For nearly two weeks, while the larva is growing up, the meals thus follow in succession, one by one, as needed, and coming closer together as the infant grows larger. Towards the end of the two weeks, the mother is kept as busy as she can be satisfying her hungry child, now a large, fat grub. You see her at every moment coming back with a fresh capture, at every moment setting out again upon the chase. She does not cease her efforts until the grub is stuffed full and refuses its food. I have counted and found that sometimes the grub will eat as many as eighty-two Flies. I have wondered sometimes why this Wasp does not lay up a store of food, as the other Wasps do, close the door of her burrow and fly away, instead of waiting about, as she does so patiently. I realize that she does not do so because her Flies would not keep; they would spoil and be unfit for eating. But why does she kill the Fly instead of paralyzing it? Possibly because the Fly would not make a satisfactory preserved food; it is so slight and frail, it would shrivel up and there would be nothing of it; it must be eaten fresh to be worth anything. Another reason almost certainly is that the Fly has to be captured very quickly, on the wing. There is not time for the Wasp to aim her sting, as the Wasps do who are killing clumsy Worms or fat Crickets on the ground. She must attack with claws, mouth or sting wherever she can, and this method of attack kills at once. It is not easy to surprise a Wasp hunting, as she flies far away from where her burrow lies; but one day I had a quite unexpected experience as I was sitting in the hot sun under my umbrella. I was not the only one to enjoy the shade of the umbrella. Gad-flies of various kinds would take refuge under the silken dome and sit peacefully on every part of the tightly stretched cover. To while away the hours when I had nothing to do, it amused me to watch their great gold eyes, which shone like carbuncles under my umbrella; I loved to follow their solemn progress when some part of the ceiling became too hot and obliged them to move a little way on. One day, bang! The tight cover resounded like the skin of a drum. Perhaps an oak had dropped an acorn on the umbrella. Presently, one after the other, bang, bang, bang! Can some practical joker be flinging acorns or little pebbles at my umbrella? I leave my tent and look around: nothing! I hear the same sharp sounds again. I look up at the ceiling and the mystery is explained. The Fly-hunting Wasps of the neighborhood, who all eat Gad-flies, had discovered the rich game that was keeping me company and were impudently coming into my shelter to seize the Flies on the ceiling. Things were going to perfection: I had only to sit still and look. Every moment a Wasp would enter, swift as lightning, and dart up to the silken ceiling, which resounded with a sharp thud. Some rumpus was going on aloft, where so lively was the fray that one could not tell which was attacker, which attacked. The struggle did not last long: the Wasp would soon retire with a victim between her legs. The dull herd of Gad-flies would not leave the dangerous shelter. It was so hot outside! Why get excited? [Illustration: “One day, bang!”] Let us watch the Wasp as she returns to the burrow with her capture held under her body between her legs. As she draws near her home, she makes a shrill humming, which has something plaintive about it and which lasts until the insect sets foot to earth. The Wasp hovers above the sand and then dips down, very slowly and cautiously, all the time humming. If her keen eyes see anything unusual, she slows up in her descent, hovers for a second or two, goes up again, comes down again and flies away, swift as an arrow. We shall see in a few moments what it is that makes her hesitate. Soon she is back again, looks at things once more from a height, then comes down slowly and alights at a spot which looks exactly like the rest of the sandy surface. I think she has landed more or less on chance, and will now look about for the entrance to her home. But no; she is exactly over her burrow. Without once letting go her prey, she scratches a little in front of her, gives a push with her head, and at once enters, carrying the Fly. The sand falls in, the door closes, and the Wasp is at home. It makes no difference that I have seen this Wasp return to her nest hundreds of times; I am always astonished to behold the keen-sighted insect find without hesitation a door which does not show at all. The Wasp does not always hesitate in the air before alighting at her house, and when she does, it is because she sees her nest is threatened by a very grave danger. Her plaintive hum shows anxiety; she never gives it when there is no peril. But who is the enemy? It is a miserable little Fly, feeble and harmless in appearance, whom we have mentioned in another chapter. The Wasp, the scourge of the Fly-tribe, the fierce slayer of large Gad-flies, does not enter her home because she sees herself watched by another Fly, a tiny dwarf, who would make scarcely a mouthful for her larvæ. I feel just as I should if I saw my Cat fleeing in terror from a Mouse. Why does the Wasp not pounce upon the little wretch of a Fly and get rid of her? I do not know. It must be because this wretched little Fly has her tiny part to play in the universe, as well as the Wasp. These things are ordered somehow, in a way we do not understand. [Illustration] As I shall mention elsewhere, this is the Fly that lays her eggs on the game the Wasp puts in the nest for her own baby; and the Fly’s offspring eat the food of the Wasp-grub, and sometimes eat the grub itself, if provisions are scarce. The way the Fly manages her business is interesting. She never enters the Wasp’s burrow, but she waits with the greatest patience for the moment when the Wasp dives into her home, with her game clasped between her legs. Just as she has half her body well within the entrance and is about to disappear underground, the Fly dashes up and settles on the piece of game that projects a little way beyond the hinder end of the Wasp; and while the latter is delayed by the difficulty of entering, the former, with wonderful swiftness, lays an egg on the prey, or even two or three in quick succession. The hesitation of the Wasp, hampered by her load, lasts but the twinkling of an eye. No matter: the Gnat has accomplished what she wished to, and now she goes and squats in the sun, close to the burrow, and plans fresh deeds of darkness. A number of these Flies, usually three or four, are apt to station themselves on the sand at one time near a burrow, of which they well know the entrance, carefully hidden though it be. Their dull-brown color, their great blood-red eyes, their astonishing patience, have often reminded me of a picture of brigands, clad in dark clothes, with red handkerchiefs around their heads, waiting in ambush for an opportunity to hold up some travelers. [Illustration] It is when the poor Wasp sees these brigands that she hesitates. At last she comes nearer, however. The Midges then take flight and follow behind the Wasp. If she turns, they turn also, so as to keep exactly behind her; if she advances, they advance; if she retreats, they retreat. She cannot keep them off. At last she grows weary and alights; they also alight, still behind her. The Wasp darts off again, with an indignant whimpering; the Midges dart after her. The Wasp tries one more way to get rid of them. She flies far away at full speed, hoping that they will follow and lose their way. But they know too much for that. They settle down on the sand again near the burrow and wait for her to come back. Come she does; the pursuit begins all over again; the mother’s patience is worn out, and at last they have a chance to lay their eggs as she goes into the burrow.