Page:Popular Science Monthly Volume 45.djvu/462

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THE POPULAR SCIENCE MONTHLY.

brown in color, with leathery wings overlapping each other on its back; thick legs, along the sides of which are fringes for swimming; and a flat, boat-shaped body which offers little resistance to the water.

The eggs of the American belostoma are deposited on pieces of wood or reeds along the margins of ponds, apparently where PSM V45 D462 American belostoma.jpgFig. 1.—American Belostoma. they will be wet but not directly in the water. They are laid in clusters of from forty to sixty or more in each. The eggs themselves are about one fifth of an inch long, oblong-ovate in form, with the general color brown spotted with black; they are lighter colored below than above, and there is a whitish crescent near the top with a distinct black spot in its apex. This crescent indicates the margins of a little cap which comes off when the young bugs hatch.

Little seems to be known concerning the early history of these They probably crawl into the water soon after hatching, and live upon such aquatic insects as they are able to catch. I do not know just how fast they grow, but presume they become full grown in a year. During the earlier period of their existence they have no wings; they are then in what the naturalists call the nymph state. Their appearance just before they become adult is represented in Fig. 2. It will be seen that they have no PSM V45 D462 Last stage of belostoma nymph.jpgFig. 2.—Last Stage of nymph. wings, but otherwise they very much resemble the full-grown bugs. Finally, the skin splits open along the middle of the back, and the insect crawls out of its old skin clothed in a new one which is provided with wings. It now for the first time can leave the pond where it has developed, and fly away to other bodies of water.

If the front leg of a full-grown American belostoma be examined carefully, there will be found on the front margin of the long joint nearest the body a longitudinal groove for the reception of the next joint. By this character the present species can always be distinguished from the other one, in which there is no groove. This latter insect is called Belostoma griseus. It is usu-