The insect now reaches the edge of the sill, and, taking a fresh grip on her burden, starts off in a bee-line across my drawing-board and towards the open door, and disappears. Wondering what her whimsical destination might be, my eye involuntarily began to wander about the room in quest of nail-holes or other available similar crannies, but without reward, and I had fairly settled back to my work and forgotten the incident, when the same visitor, or another just like her, again appeared, this time clearing the window-sill in her flight, and landing directly upon my drawing-board, across which she sped, half creeping, half in flight, and tugging her green caterpillar as before—longer than herself—which she held beneath her body.
"This time I shall learn your secret," I thought. "Two such challenges as this are not to be ignored." So I concluded this time to observe her progress carefully. In a moment she had reached the right-hand edge of my easel-board, from which she made a short flight, and settled upon a large table in the centre of the room, littered with its characteristic chaos of professional paraphernalia—brushes, paints, dishes, bottles, color-boxes, and cloths—among which she disappeared. It was a hopeless task to disclose her, so I waited patiently to observe the spot from which she would emerge, assuming that this, like the window-sill and my easel, was a mere way-station on her homeward travels. But she failed to appear, while I busied my wits in trying to recall which particular item in the collection had a hole in it. Yes, there was a spool among other odds and ends in a Japanese boat-basket. That must be it! But on examination the paper still covered both ends, and I was again at a loss. What, then, can be the attraction on my table? My wondering curiosity was immediately satisfied, for as I turned back to the board and resumed my work I soon discovered another wasp, with its caterpillar freight, on the drawing-board. After a moment's pause she made a quiet short flight towards the table, and what was my astonishment to observe her alight directly upon the tip of the very brush which I held in my hand, which, I now noted for the first time, had a hole in its end! In another moment she disappeared within the cavity, tugging the caterpillar after her!
A Corner of My Table
My bamboo brushes! I had not thought of them! By mere chance a few years since I happened upon some of these bamboo brushes in a Japanese shop—large, long-handled brushes, with pure white hair nicely stiffened to a tapering point, which was neatly protected with a sheathing cover of bamboo. A number of them were at my elbow, a few inches distant, in a glass of water, and on the table by the vase beyond were a dozen or so in a scattered bundle.
Normally each of these brushes is closed at the end by the natural pith of the bamboo. I now find them all either open or otherwise tampered with, and the surrounding surface of the table littered with tiny balls, apparently of sawdust. I picked up one of the nearest brushes, and upon inverting it and giving it a slight tap, a tiny green worm fell out of the opening. From the next one I managed to shake out seven of the caterpillars, while the third had passed beyond this stage, the aperture having been carefully plugged with a mud cork, which was even now moist. Two or three others were in the same plugged condition, and investigation showed that no single brush had escaped similar tampering to a greater or less extent. One brush had apparently not given entire satisfaction, for the plug had been removed, and the caterpillars, eight or ten in number, were scattered about the opening. But the dissatisfaction probably lay with one of these caterpillars rather than with the maternal wasp, who had apparently failed in the full dose of anæsthetic, for one of her victims which I observed was quite lively, and had probably forced out the soft plug, and in his squirming had ousted his luckless companions.
An Animated Brush
The caterpillars were all of the same kind, though varying in size, their length being from one-half to three-quarters of an inch. To all appearances they were dead, but more careful observation revealed signs of slight vitality. Recognizing the species as one which I had long known, from its larva to its moth, it was not difficult to understand how my brushes might thus have been expeditiously packed with them. Not far from my studio door is a small thicket of wild rose, which should alone be sufficient to account for all those victimized caterpillars. This species is a regular dependent on the rose, dwelling within its cocoon-like canopy of leaves, which are drawn together with a few silken webs, and in which it is commonly concealed by day. A little persuasion upon either end of its leafy case, however, soon brings the little tenant to view as he wriggles out, backward or forward, as the case may be, and in a twinkling, spider-like, hangs suspended by a web, which never fails him even in the most sudden emergency.
I can readily fancy the tiny hornet making a commotion at one end of this leafy domicile and the next instant catching the evicted caterpillar "on a fly" at the other. Grasping her prey with her legs and jaws, in another moment the wriggling body is passive in her grasp, subdued by the potent anæsthetic of her sting—a hypodermic injection which instantly produces the semblance of death in its insect victim, reducing all the vital functions to the point of dissolution, and then holds them suspended—literally prolongs life, it would sometimes seem, even beyond its normal duration—by a process which I might call ductile equation. This chemical resource is common to all the hornets, whether their victims be grasshoppers, spiders, cicadæ, or caterpillars. In a condition of helpless stupor they are lugged off to the respective dens provided for them, and then, hermetically sealed on storage, are preserved as fresh living food for the young hornet larva, which is left in charge of them, and has a place waiting for them all. The developments within my brush-handles may serve as a commentary on the ways and transformations of the average hornet.
A Specimen in Three Stages
One after another of the little green caterpillars is packed into the bamboo cell, which is about an inch deep, and plugged with mud at the base. From seven to ten of the victims are thus stored, after which the little wasp deposits an egg among them, and seals the doorway with a pellet of mud. The young larva, which soon hatches from this egg, finds itself in a land of plenty, surrounded with living food, and, being born hungry, he loses no time in making a meal from the nearest victim. One after another of the caterpillars is devoured, until his larder, nicely calculated to carry him to his full growth, is exhausted. Thus the first stage is passed. The second stage is entered into within a few hours, and is passed within a silken cocoon, with which the white grub now surrounds itself, and with which, transformed to a pupa, it bides its time for about three weeks, as I now recall, when—third stage—out pops the mud cork, and the perfect wasp appears at the opening of the cell. I have shown sections of one of my brushes in the three stages.
This interesting little hornet is a common summer species, known as the solitary hornet—one of them—Odynerus flavipes. The insect is about a half-inch in length, and to the careless observer might suggest a yellow-jacket, though the yellow is here confined to two triangular spots on the front of the thorax and three bands upon the abdomen.