Economic Importance of Animals 553 



Order 7 — Anoplura: These true lice are wingless parasites which 

 suck juices from man and other mammals. The three common species 

 which attack man (Fig. 280) are the head louse, the body louse, and 

 the crab louse. The rat louse, dog louse, and hog louse attack other 

 mammals. The true lice differ from the Mallophaga in having piercing- 

 sucking mouth parts. 



srxis?' 



Fig. 277. 



Fig. 278. 



Fig. 277. — An adult damsel fly of the order Odonata. Note the position of the 

 two pairs of wings when the insect is at rest. 



Fig. 278. — Stone fly (adult) of the order Plecoptera. Note the pair of tail 

 filaments at the tip of the abdomen and the resting position of the wings. . In 

 well-aerated water, the flat larva clings to stones; hence, the name stone fly. The 

 larvae make excellent fish bait. 



Fig. 279. — Biting bird* louse {Menopon pallidum) of the order Mallophaga. 

 A parasite from a chicken, much enlarged. (From Bishopp and Wood: Mites 

 and Lice on Poultry, U. S. Department of Agriculture; courtesy of the Department 

 of Entomology and Plant Quarantine.) 



