554 Animal Biology 



Order 8 — Orthoptera: Extracts from the bodies of cockroaches (Fig. 

 281) are used to a certain extent for medicinal purposes. The four 

 species of cockroaches in the United States attack foods, bedbugs, silver- 

 fishes, and other cockroaches. The "praying mantis" (Fig. 329) consumes 

 other insects as food. The "walking sticks" feed on the foliage of trees 

 and plants; they resemble the twigs that surround them in general shape, 

 making them difficult to detect. The locusts or short-horned grass- 

 hoppers (Figs. 191 to 193) devour many kinds of vegetation and, when 

 they migrate in swarms, may destroy all living plants in their paths. 



Fig. 280. — Parasitic mites (class Arachnoidea) and lice (class Insecta, order 

 Anoplura) . A, Human itch mite (Sarcoptes scahiei) , female from ventral surface; 

 B, male of mite shown in A, from ventral surface; C, body louse or "cootie" 

 {Pediculus corporis) ; D, head louse (Pediculus capitis) ; E, crab louse (Phthirius 

 pubis). (From Turner: Personal and Community Health. The C. V. Mosby 

 Co.) 



