28 



HOW INSECTS ARE CLASSIFIED 



Psj^llidse, the psyllas. Minute, jumping forms. Plant feeders. 

 Aphidida*, the plant lice. 

 Coccidae, the scale insects and mealy bugs. 

 The more important families of Heteroptera are as follows : 

 Reduviidse, the assassin bugs, Predaceous on other insects. Occa- 

 sionally attack man. Have a strong, 

 three-jointed beak. 



Tingitidse, the lace bugs. Wings finely 

 reticulate, looking like lace. Plant feed- 

 ers. 



Acanthiida}, including some plant feed- 

 ers ; also the common bedbug. 



Capsidse, the leaf bugs. Usually small. 

 Often injurious. 



Lygseidse, the chinch bugs. Destruc- 

 tive plant feeders. 



Coreidse, the squash bugs. Often ill 

 smelling. Some species rather large. 



Pentatomida), the stinkbugs. The 

 family includes both plant feeders and 

 predaceous forms. 



Thyreocoridae, the negro bugs. Very 

 small forms. 



Pediculidae, the sucking Hce, parasitic on mammals. 

 The number of described species in the Hemiptera exceeds 20,000. 



Fig. 26. — The giant water 

 bug, wings folded. Sub- 

 order Heteroptera. Origi- 

 nal. 



Coleoptera 



The order Coleoptera includes the beetles, readily distinguished, as 

 a rule, by the fact that the front pair of wings are hardened and act 

 simply as horny coverings for the larger, membranous hind wings, 

 which are folded beneath the others when at rest. 



Metamorphosis is complete. There are four distinct stages, instead of 

 three, as with all the other orders mentioned thus far. Eggs are laid 

 by the adults, and from these hatch worm^ike larvae, commonly called 



