INSECTA 99 



means for respiration. Corixa is the water-boatman 

 which has the hind legs flattened to form two great oars. 

 When swimming under water it carries air between the 

 fine hairs which cover the body and beneath the wings, 

 hence is able to stay submerged for a long time. Noto- 

 necta, the back-swimmer, is something like Corixa, but 

 usually swims with its ventral surface up. The water- 

 scorpions (Nepa, Ranatra) 

 have long slender breath- 

 ing tubes for taking air 

 from the surface of the 

 water; Nepa is flat, Ra- 

 natra is long and slender. 

 Belostoma is the giant 

 water-bug or 

 light" bug, which often 

 flies over the land at night. 

 Its small relative, Zaitha, 



FIG. 48. Heteroptera. From left to right the insects are the water-boatman 

 (Corixa) ; back-swimmer (Notonecla) ; water-stridcrs (Gerris) ; a water-scorpion 

 (Nepa) catching a minnow; a male water-bug (Zaitha) carrying eggs on his back; 

 chinch-bugs; flower- bug; assassin-bug; squash-bug. 



is of interest on account of its peculiar breeding habits. 

 The female sticks her eggs on the back of a male, and he 

 is obliged to carry them around till they hatch. The 

 marsh-treaders and water-striders (Gerris, etc.) run over 

 the surface of the water with great skill. They are kept 

 from sinking through the surface film by the little hairs on 

 the legs which cannot be wet. All the aquatic bugs are 



