HOW TO KNOW THE IMMATURE INSECTS 



9b. Beak 3-segmented; hind femur not extending much beyond the 

 apex of abdomen. Fig. 363 Family VELIIDAE 



The broad-shouldered water-striders are close- 

 ly allied to the Gerridae. The distal segment of 

 the tarsi, at least of the fore leg is bifid and the 

 claws are inserted before the apex. They are 

 predacious and live on the water surface. About 

 20 species have been described in the United 

 States. 



Fig. 363. Mesovelia 

 mulsanti White. 



10a. Beak 3-segmented 11 



10b. Beak 4-segmented 13 



11a. Body broad and flat, without wing pads; parasitic. 



Fig. 364 Family CIMICIDAE 



Fig. 364. Bed bug Cimex 

 lectularius L., newly 

 hatched. 



These are bedbugs and swallow bugs, 

 about 36 described species. Among them, 

 2 species attack humans: the bedbug, Ci- 

 mex lectularius L. in temperate and sub- 

 tropical regions; Cimex lotundatus Signor- 

 et in tropical Africa and Asia. The former 

 has a straight posterior margin of the pro- 

 thorax while the latter is rounded. 



lib. With wing pads; not parasitic. 



12 



12a. Fore legs with greatly thickened femora. 



Fig. 365 Family PHYMATIDAE 



This family of "ambush bugs" 

 contains about 150 described spe- 

 cies. They feed upon many kinds 



Fig. 365. a, Ambush bug, Phymoto of insects including honey bees, 

 erosa fasciota (Gray); b, fore leg. 



132 



