The Wonderful Ways of Insects and Spiders [ 271 



This accounts for such local names as "apple bug" and "vanilla 

 bug." 



THE SPEEDY WATER STRIDER 



Water striders, usually found in fresh or brackish water, 

 have very long slender middle and hind legs. It is difficult to 

 capture them, as they skate away with great speed. The middle 

 pair of legs propel this bug over the water while the hind pair 

 steer. Its color is a dull dark brown above, with a silvery-white 

 underside. 



THE UPSIDE-DOWN BUG 



Another water insect, the back swimmer, is named for 

 its habit of swimming on its back, which is shaped like the bottom 

 of a canoe. You may first notice it as it hangs head downward in 

 the water; but when it is alarmed, it propels itself swiftly away 

 bottom side up! pushing with its hind legs. 



The more common species are about half an inch long, and 

 have enormous compound eyes. The back, which you do not 

 see when they are swimming, is pearly-colored; the underside, 

 which you do see, is darker. The back swimmer is easily con- 

 fused with the water boatman, which is quite similar in appear- 

 ance; but the boatman is smaller and never swims on its back, 

 All these bugs, with the exception of some wingless water striders, 

 fly at night and are strongly attracted to lights. 



THE CADDIS FLY AND ITS PROTECTIVE COVERING 



Among the fascinating population of ponds and streams 

 there are some creatures which, like the dragonfly, spend their 

 early life in the water and then, as adults, proceed to live on land 

 and in the air. Look in shallow pools for one of the most interest- 

 ing of these. At first you may see what appears to be a stick, one 

 or two inches long and half an inch around. If it starts to move 

 itself along the bottom or up the stem of a plant, you know it is 

 "animal" rather than "vegetable." 



This is the larva of a small mothlike insect called the caddis 

 fly. Many caddis fly larvae make cases of pebbles, sticks, or other 



