SEGMENTED SCHIZOCOELS 



245 



snow; sometimes damage plants; include the remark- 

 able ice-inhabiting snow and glacier fleas. 



Subclass PTERYGOTA: Division Exopterygota 



Diagnosis: winged or from winged ancestors; no 

 ventral, abdominal, bristle-like appendages; division 

 Exopterygota metamorphosis; gradual, young stages 

 are nymphs and have compound eyes; wings develop 

 externally. 



ORDER ORTHOPTERA (Grasshoppers, Chckefs, 

 Roaches, Walking Sficks, Maniids, and allies) 



Diagnosis: medium size to fairly large; front wings 

 thickened, hind wings folded like a fan; chewing 



mouth parts; males of jumping forms "sing" by rub- 

 bing wings or hind legs against wings; widespread, 

 mostly scavengers and predators; include some of the 

 most destructive insects, crickets and grasshoppers 

 destroy crops, roaches destroy clothing and leave a 

 disagreeable odor, walking sticks rarely harm plants, 

 mantids are mostly valuable predators of harmful 

 insects (Figure 14.22). 



ORDER DERMAPTERA (Earwigs) 



Diagnosis: small to medium size, about 1/6 to 1 

 inch; front wings short and leathery, hind wings long 

 and membranous; chewing mouth parts; abdomen 

 terminated by pincers; often common in garbage and 

 damp places, mostly scavengers but also predators 

 and herbivores; mostly active at night and hide in 



Figure 14.22 Order Orthoptera: 1, Acrididae, short-horned grasshopper or locust (x '2); 2, Tet- 

 tigoniidae, a katydid (x ' -j); 3, Gryllacrididae, a camel or cave cricket {x 1); 4, Tettigoniidoe, a 

 shield-backed grasshopper ( x ' -2); 5, Tetrigidae, a pygmy or grouse locust ( x 2); 6, Gryllidae, a field 

 cricket {x 1); 7, Gryllidae, o tree cricket (x !'■_•); 8, Gryllotalpidae, a mole cricket (x 1); 9, Tri- 

 doctylidae, a pygmy sond or mole cricket (x 7); 10, Gryllacrididae, a sand or Jerusalem cricket 

 (locally known as a potato "bug" or child of the earth, to about 3 inches long),- 1 1, Mantoideo, o 

 mantid or preying mantis (to 4 inches long); 12, Phasmatidae, a walking stick or stick insect (to obout 

 3 inches long); 13, Blottidae, a roach or cockroach (to about 2 inches long); 14, Grylloblattidae, a 

 grylloblattid ( x 1 ). (After various sources.) 



