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.
We shall end our chapter with the story of the Wasp-grub to whom no accidents happen, into whose burrow no nasty Fly-eggs enter. For two weeks it eats and grows; then it begins to weave its cocoon. It has not very much silk in its body to use for this, so it uses grains of sand to strengthen it. First it pushes away the remains of its food and forces them into a corner of the cell. Then, having swept its floor, it fixes to the different walls of its room threads of a beautiful white silk, forming a web which makes a kind of scaffold for the next work.
It then weaves a hammock of silk in the center of the threads. This hammock is like a sack open wide at one end and closed at the other in a point. The grub, leaning half out of its hammock, picks up the sand almost grain by grain with its mouth. If any grain found is too large, it is thrown away. When the sand is sorted in this way, the grub brings some into the hammock in its mouth, and begins to spread it in an even layer on the lower side of the hammock-sack; it adds grains also to the upper side, fixing them in the silk as one would place stones in putty.
The cocoon is still open at one end. It is time to close it. The grub weaves a cap of silk which fits the mouth of the sack exactly, and lays grains of sand one by one upon this foundation. The cocoon is all finished now, except that the grub gives some finishing touches to the inside by glazing the walls with varnish to protect its delicate skin from the rough sand. It then goes peacefully to sleep, to wait for its transformation into a Wasp like its mother.
CHAPTER XI
PARASITES
In August or September, let us go into some gorge with bare and sun-scorched sides. When we find a slope well-baked by the summer heat, a quiet corner with the temperature of an oven, we shall call a halt; there is a fine harvest to be gathered here. This tropical land is the native soil of a host of Wasps and Bees, some of them busily piling the household provisions in underground warehouses—here a stack of Weevils, Locusts or Spiders, there a whole assortment of Flies, Bees, or Caterpillars,—while others are storing up honey in wallets or clay pots, cottony bags or urns made with pieces of leaves.
With the Bees and Wasps who go quietly about their business, mingle others whom we call parasites, prowlers hurrying from one home to the next, lying in wait at the doors, watching for a chance to settle their family at the expense of others.
It is something like the struggle that goes on in our world. No sooner has a worker by means of hard labor gotten together a fortune for his children than those who have not worked come hurrying up to fight for its possession. To one who saves there are sometimes five, six or more bent upon his ruin; and often it ends not merely in robbery but in black murder! The worker’s family, the object of so much care, for whom that home was built and those provisions stored, is devoured by the intruders. Grubs or insect-babies are shut up in cells closed on every side, protected by silken coverings, in order that they may sleep quietly while the changes needed to make them into full-grown insects take place. In vain are all these precautions taken. An enemy will succeed in getting into the impregnable fortress. Each foe has his special tactics to accomplish this—tactics contrived with the most surprising skill. See, some strange insect inserts her egg by means of a probe beside the torpid grub, the rightful owner; or else a tiny worm, an atom, comes creeping and crawling, slips in and reaches the sleeper, who will never wake again, because the ferocious visitor will eat him up. The interloper makes the victim’s cell and cocoon his own cell and cocoon; and next year, instead of the mistress of the house, there will come from below ground the bandit who stole the dwelling and ate the occupant.