THE INSECT WORLD. 



151 



Streams, where it feeds on other insects and small fish, destroy- 

 ing large numbers. During the night the winged individuals 

 leave the ponds, pair, and fly to new localities to lay their eggs. 

 So abundantly do they occur that they sometimes become nui- 

 sances near electric lights, and have been termed firom this fact 

 ' ' electric-light bugs. ' ' 



Sometimes we find slender, spider-like creatures of a brown 

 color scudding over the surface of the water at a rapid rate, and 



Fig. 112. 



A water-strider, Rheumatobates rileyi, female. — a, anterior tarsus ; b, ovipositor ; c, hind 



tarsus. 



these are "water striders," or Hydrobatidce. They are inter- 

 esting because some of them pass their entire lives upon the 

 ocean, miles from land. These are said to feed upon the juices 

 of such dead fish and other animals as they find on the surface, 

 and probably also on the floating masses of sea- weed occurring 

 in equatorial regions where they are most common. 



The first family of economic importance among the terrestrial 

 species is the Reduviidce, containing species of quite large size, 



