PHYLUM ARTHROPOD A 



277 



other diverse forms, characterized by the incomplete The Rhyn- 

 metamorphosis and the sucking instead of biting mouth chota 



From Bulletin 67, U. S. National Museum 



FIG. 96. The "seventeen-year locust" (Tibicina septendecim) : a, b, adult insects; 

 c, shell of nymph, after emergence of adult. 



parts. In male scale insects the metamorphosis is more 

 nearly complete, there being a resting pupa stage. 



The Rhynchota consist of two great divisions, by Divisions of 

 some regarded as separate orders. In the Homoptera. 

 the anterior wings are of nearly the same consistency 

 throughout, whereas in the Heteroptera (or Hemiptera 

 proper) the front wings or hemelytra are membranous 

 apically, with the basal part more or less hard and 

 opaque, in the manner of the elytra of beetles. The 

 division between the two parts is abrupt, and the divid- 

 ing line is more or less oblique. The Homoptera include 

 some very peculiar groups, such as the scale insects 

 (Chapter 41) and aphids or plant lice, but the more 

 typical form of the suborder is that of the so-called 

 seventeen-year locust, a large species of cicada. The 

 Heteroptera include many plant bugs, and others which 

 are predatory, feeding on different insects. Some, such 

 as the bedbug, suck the blood of vertebrates. 



