AQUATIC INSECTS 



known as Zaitha fluminea. It clings to stems and sticks in 

 still waters which hold a congested population of water plants 

 and insects — mayflies, damselflies, and the like. The eggs, 

 a hundred more or less, are carried on the back of the male 

 (Fig. 175) until they hatch, usually for ten days or more. . 

 Torre-Bueno has thus described the transfer of the parental 

 burden. "The female places herself on top of the male, her 

 thorax extending outward and her legs hooked under him; 

 now starting somewhere near the middle and sidling along 

 every little while, she works her way around him as she 

 fastens her eggs on his back by means of the water-proof glue 

 secreted for that purpose. The male all the while hangs 

 from the surface, back up, with his legs curled up under him, 

 bravely bearing up under his burden." 



Occurrence. — Egg-laden males can be found commonly from 

 May into early September. In the marsh waters at Ithaca, 

 N. Y., they are very plentiful in August. Adults, one inch 

 long. 



Fig. 176. — Electric-light bug, Lethocenis ameri- 

 canus, and front leg showing groove on the femur 

 into which the tibia can be folded. 



233 



