Wasps

Abstract

A COUPLE of weeks ago I found on my window-pane a large black wasp holding in its mandibles a plump spider of about an eighth of an inch in diameter. I placed the wasp under a bell-glass and set it on my desk, where I could readily watch for further developments. Finding itself in captivity, the wasp dropped its booty and spent some time in trying to find a way of escape. Coming at length to a state of rest, it espied the spider and sprang upon it with tiger-like fierceness. Seizing it and raising itself up to its full height, the wasp brought its posterior under and forward with a quick motion, and gave the spider, two or three thrusts with its sting. Assured that the spider was dead, the wasp proceeded to roll it over and over, rapidly working it up into a globular mass. This done it started to fly away; but, foiled in the attempt, it dropped the spider, which was for some time apparently forgotten. This whole operation I saw several times repeated during the two days of my observations. Being called away from home for a few days, I was curious on my return to ascertain the results of my experiment. I had taken the precaution at the first to place under the bell-glass a small dish of clean water, to which the wasp had helped itself freely. I found the wasp dead; but not the least morsel of the spider had it eaten. My conclusions are: (1) that the wasp died of starvation; (2) that the spider was intended, not for its own food, but for that of its young in their larval state. In confirmation of this I have broken open several of the finished cells of these wasps, and found them filled with pellets made of portions of spiders, flies, and worms. Only yesterday a fine opportunity was afforded me for further observations in this direction. One of my flowering vines is infested with a green worm—the larva of the yellow butterfly. I discovered a bronze-and-yellow wasp standing on the edge of a leaf of this vine, holding fast to one of these worms of twice its own size. The worm was dangling in mid-air, and the wasp endeavoured laboriously for a long time to pull it up on the surface of the leaf. Failing in this, with a dexterity worthy of the Knight of the Shears it cut the worm in two, letting about three-fourths of it fall to the ground. The remainder was then easily dragged to the surface of the leaf, where the wasp spent some fifteen minutes in cutting down, trimming, and reducing it to a globular mass of about an eighth of an inch in diameter. Then resting for a few minutes, and taking a fresh held of its booty, it flew briskly away.