PHYLUM ARTHROPODA 



345 



(4) ACRIDIID.E (LOCUSTS OR SHORT-HORNED GRASSHOPPERS, 

 Fig. 272). The locusts have leaping legs and short antennae. 

 They feed on vegetation and often do considerable damage. 

 The most famous species is Melanoplus spretus, the Rocky 

 Mountain locust (Fig. 272), which is occasionally migratory 

 and devours everything in its path. The red-legged locust, 

 Melanoplus femur-rubrum, and thfc Carolina locust, Dissosteira 

 Carolina, are common species. 



(5) LOCUSTHXE (LONG-HORNED GRASSHOPPERS, Fig. 273). 

 The members of this family have slender antennae longer than 

 the body. The meadow grasshoppers and katydids belong here. 



(6) GRYLLID.E (CRICKETS, Fig. 274). The mole crickets 

 burrow in the ground; the true crickets are those that make 

 themselves known by their chirping about houses; the tree 

 crickets inhabit trees. 



Order ii. Hemiptera. BUGS, LICE, APHIDS, SCALE INSECTS 

 (Fig. 275-279). Insects without wings or with four wings; 

 one suborder with fore-wings thickened 

 at base; sucking mouth-parts; meta- 

 morphosis incomplete. 



HEMIPTERA may be separated con- 

 veniently into three suborders. 



(i) PARASITICA (LICE, Fig. 275). 

 This suborder is represented in North 

 America by a single family, the PEDI- 

 CULID^E. These are wingless and para- 

 sitic on the bodies of man and other 

 mammals. They have claws fitted for 

 clinging to hairs, and an unjointed 

 beak for penetrating the skin and suck- 

 ing juices. The species infesting man 

 are Pediculus capitis, the head-louse bridge Natural History, after 



Pl3.Gt ) 



(Fig. 275), P. vestimenti, the body-louse, 



and Phthirius inguinalis, the crab-louse. Domestic animals are 



infested by members of the genus Hamatopinus. H. pilifems 



FIG. 275. Order HEMIP- 

 TERA. Head-louse, Pediculus 

 capitis. (From the Cam- 



