8g6 FRESH-WATER BIOLOGY 



green herbs. Those of Notonecta are deposited singly on the sides 

 of plant stems under water, and those of Corixa are deposited in 

 similar places or stuck on to the back of crawfishes. 



The surface-haunting forms are characteristically of scavenger 

 habits, eating the insects of all sorts that fall upon the surface of 



Fio. 1366. The eggs of the giant water bug, Benacm, on the 

 base of a Typha stem. 



the water; while the more strictly aquatic bugs are truly predatory 

 with the possible exception of the minute Plea, which is believed 

 not to be carnivorous at all. The highly specialized Corixidae are 

 able to remain wholly submerged for long periods. They clamber 

 about amid the debris of the pond bottom, and when they come to 

 the surface for air, they do not remain there, but quickly descend 

 again to the shelter of the bottom trash. Of all Hemiptera these 

 are the ones most commonly eaten by fishes. 



