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.
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.