What, May; you want to see a bug? Well, that is easy enough. Here is one in this pond at our feet. Do you know it? The Water Boatman Yes, John; it is the water boatman. Nell says she doesn't see it. There, Nell, that little thing that shines like silver under the water. It is clinging to a weed. No, we cannot see it very well unless we catch it. Ned, do you think you can be spry enough to scoop it out with the net? There, he has it,—no, it is off. Well, we shall never see that one again; but here, in this corner of the pond, see, several of them. The Water Boatman Now don't be in too great a hurry, Ned; they are hard to catch. He has it! Here, don't touch it,—bugs are biters, remember. Put it in this tumbler of water, and clap the cover over it—quick—so!—now we have it. What is that, Mollie? I just said bugs do not bite, and now I call them biters? I don't wonder you are puzzled. They do not bite, but they pierce with their mouth tubes, and that feels just as though they bit us. So we commonly speak of bugs as biting. If you wish to be very exact, we will hereafter speak of bugs as piercing or sucking. Now, Mr. Water Boatman, we are going to have a good look at you. Nell says it is not like silver any more, but just a little black and gray speckled bug. That is because it is now on top of the water. When it goes under it is surrounded with a layer of air, and that is what makes it look as though it had on a silver dress. May wants to know how it manages to take a layer of air down under the water. If you were to look at it with a magnifying glass, May, you would see it is covered with fine hairs; the air becomes entangled in these hairs. Do you not remember how the leaf of the jewel weed, or touch-me-not, as it is also called, shines when you plunge it in water? It, too, is covered with fine hairs that hold air. Many leaves shine in this way Our water boatman breathes this air that surrounds him. You know how insects breathe do you not? Dear me, then I shall have to tell you. They have no lungs; of course, so they cannot breathe with lungs as we do. Take a long breath—see how your chest rises—that is because you filled your lungs full of air. Well, the insects have to breathe air. Every living thing has to breathe air. Nothing in the world could live without air. Even plants breathe the air, you know. Now, there is a little row of holes or pores along each side of the abdomen of the insect. These are the breathing pores. No, May, the insects do not breathe through their mouths, they breathe through their sides. The Water Boatman You can see the breathing pores, or spiracles, as they are called, very plainly in many insects. You can see them on the abdomen of the locust, and in some caterpillars they are bright-colored spots. There are spiracles on the sides of the thorax, too, but they do not show so plainly as those on the abdomen. The spiracles open into air tubes that carry air to the blood of the insect. Spiracles Spiracles If you watch a grasshopper or a bee, you can plainly see it breathe. The abdomen moves in the bee as though it were panting. These movements of the abdomen cause the air to go in and out. All insects move their abdomens to send the air in and out, but it does not show plainly in all of them, for, though insects need air, some of them can get along with very little. Yes, John, insects have blood. It is not just like our blood, but still it is blood. It is not generally red in color, though sometimes it is reddish, and sometimes it is brown, or violet, or even bright green. Yes, that seems strange to you, but you remember how ears are ears, and serve to hear with, no matter where on the body of the creature they are located. Yes, Mabel, it is probably used, like the "molasses" of other little friends we know, to repel enemies. But to return to breathing. Some larvÆ breathe by gills, and do not have spiracles until they are grown up, but all grown-up insects breathe by spiracles. Yes, John, the larvÆ of the dragon flies and May flies breathe with gills. I thought you would remember that. The water boatman breathes by spiracles, and carries his supply of air with him. All grown-up bugs breathe by spiracles. Now look down into the pond. I think you will see some water boatmen anchored near the bottom. Yes, May, they cling by their front feet. Their hind pair of legs are rather odd-looking; they have a fringe of hairs on the inside. John says their hind legs are modified to swim with. Very good, John. The hind legs are the oars that row these little boats about in the water. But why are the little boats that have come to anchor down there moving their paddles so constantly? Ah, yes; it is because they want fresh air to breathe. You know there is always air in pond water, and they keep their paddles moving, so as to change the envelope of air that surrounds them. The Water Boatman They know what to do to take care of themselves, if they are nothing but little bugs. When winter comes, they go down to the bottom of the pond and bury themselves in the mud. They lie there without moving or breathing until spring, when out they come, as lively as ever. Yes, certain other animals pass the winter in this way; the bears, for instance, find a snug den and sleep all through the coldest winter weather. We call this winter sleep of animals hibernation, and many of the insects hibernate. Yes, Ned, hibernating animals can get on with very little air; they sometimes seem to need none at all, and they take no food. May wants to know what these queer water boatmen eat. They suck out the juices of other insects. They must lay their eggs in the water, little Nell thinks. And so they do, on water plants. Near the city of Mexico there are species that lay enormous quantities of eggs in the ponds, and what do you think? The Indians mix these eggs with meal, make them into cakes, and eat them. The Mexican bugs are gathered by the ton, too, and sent to England as food for cage birds, fish, and poultry. Little Nell thinks there must be a great many bugs in a ton. Indeed, there are, probably about twenty-five millions of them; so you can imagine Mexico is well supplied with water boatmen! When the young ones hatch out they look like their parents, only, of course, they are tiny little dots of things that have no wings. The Water Boatman But they eat and grow and moult like other larvÆ until they are full-grown insects. What have you discovered, Ned? You look surprised. The water boatman has no antennÆ! It doesn't seem to have any. But look carefully and I think you will find some tiny ones tucked away under its head. Nell wants to know if the water boatman has a thorax and an abdomen. Indeed, it has, but you will have to look carefully to see them. Its abdomen is short and thick and hard. The water boatman is much more compact in form than the Orthoptera, or any of the other insects we have studied. You are right, John, an insect with a long abdomen, like the grasshopper, could not get on very well in the water. Now, May, take the cover off the tumbler. There! Our water boatman was not slow to make use of his wings. Well, good-by and good luck to you, little water boatman. The Water Boatman |