HEMIPTERA 367 



ciesof this genus, i?ewacM5 gnseus, is found in our fauna. This close- 

 ly resembles Lethocerus americanus (Fig. 419), but can be distinguish- 

 ed from that species by the absence of the groove in the femora of the 

 fore legs. 



Belostoma. — To this genus as now recognized belong our more com- 

 mon representatives of the smaller members of this family. These 

 have long been known incorrectly under the generic name Zaitha. 

 Our most common species is Belostoma flummea (Fig. 420). 



In this genus and the following one the eggs are carried by the 

 males on their backs, where they are placed by the females, sometimes 

 in spite of vigorous opposition on the part of the male. 



Abedus. — Five species of this genus have been found in the south- 

 western parts of the United States. Figure 421 represents the male 

 of one of these carrying his load of eggs. 



Family NAUCORID^ 



The Creeping Water-Bugs 



The Naucoridffi includes fiat-bodied, chiefly oval insects, of 

 moderate size. The abdomen is without caudal appendages. The 

 front legs are fitted for grasping, the femora being greatly enlarged; 

 the middle and hind legs are suited for crawling rather than for 

 swimming. There are no ocelli ; the antennae are very short, and well 

 concealed beneath the eyes; the beak is three-jointed and covered 

 at the base by the large labrum ; and the hemelytra are furnished with 

 a distinct embolium. 



Although these are aquatic insects, they have been comparatively 

 little modified for such a life. They carry air beneath their wings 

 and obtain this air by pushing the tip of the abdomen 

 above the surface of the water. 



They are predacious and are fond of reedy and 

 grassy, quiet waters, where they creep about like the 

 dytiscid beetles, creeping and swimming around and Fig. 422. — Pel- 

 between the leaves and sprays of the submerged plants, ocorisfemor- 

 seeking their prey. 



Only two genera of this family are represented in our fauna ; these 

 are Pelocoris and Amhrysus. In Ambry sus the front margin of the 

 prothorax is deeply excavated for the reception of the head; in 

 Pelocoris this is not the case. 



Pelocoris. — Only three speciesof thisgenus are found in this country 

 and these are restricted to the eastern half of the United States. 

 The most common one is Pelocoris femordtus (Fig. 422). It measures 

 about Q mm. in length, and when alive is more or less greenish testa- 

 ceous in color; but after death it is pale yellow or brownish in color, 

 with black or dark brown markings. 



Ambrysus. — Ten species of this genus have been found in this 

 coimtry; they are restricted to the Far West. 



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