FIELD BOOK OF INSECTS. 



In this sense, the females of Belostoma, and of certain 

 other genera, fasten their eggs onto the backs of the males. 

 It is said that the males do not take kindly to this procedure 

 but that they can not help themselves. 



1. Hind tibiae much broader than middle ones; front 

 coxae little longer than broad 2. 



Hind tibiae little, if any, broader than middle ones; 

 front coxae at least twice as long as broad. All of our 

 species are less than I in. long Belostoma. 



2. Margins of front femora with a longitudinal groove 

 in which the tibiae lie when folded. Letkocerus, of which 

 americanus is our common species; it is about 2 in. long. 



Margin of front femora without such groove. Benacus 

 griseus (Plate XXV). 



NEPID.E 



The long respiratory tail of Water-scorpions is not 

 fully developed- until the molt which gives them wings. 

 It is perfectly harmless; all the sting these creatures have 

 is at the other end, their beak. We have two genera, 

 both of which are aquatic and predaceous: the body of 

 Nepa is oval, flat, and thin; that of Ranatra (Plate XXV) 

 is linear and cylindrical. They are sluggish creatures, 

 crawling but not swimming, often remaining motionless 

 for hours on the muddy, leaf-covered bottom of their 

 favorite haunts and rarely, if at all, coming to lights. 

 Their eggs, which are placed in or on submerged objects, 

 are furnished with filaments at one end, seven in Nepa 

 and two in Ranatra. The only species of Nepa is apiculata, 

 which is about .75 in. long, not counting filaments. R. 

 americana, about 1.25 in. long, is our most common species 

 of Ranatra in the East. 



NOTONECTID/E 



The Back-swimmers are shaped somewhat like an over- 

 turned boat, but they overturn themselves when they are 

 in the water. They are lighter than water and normally 

 rest at the surface, floating head-down, with the tip of the 

 abdomen piercing the surface-film, their long hind legs 

 extended like sweeps ready to send them swiftly to safety 



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