106 OUTLINES OF ENTOMOLOGY. 



like over the body. In several large groups they are transparent, and 

 supported by many or few strong veins ; in others they are tough and 

 opaque, and show many different colors. The head is broad, but 

 usually very short, without any neck, and has the beak arising so far 

 under that it seems to be attached to the breast, against which it may 

 be closely folded. The eyes are round and prominent. The antennie 

 in the larger species are very inconspicuous, but in the more minute 

 forms are long, and often beautifully feathered. Some species are 

 provided with a strong, horny ovipositor by which the eggs are inserted 

 into woody stems or branches of trees ; others place their eggs on 

 exposed surfaces, or under loosened bark. 



The most important families of homopterous insects are the CiCA- 

 DiD^, Membracid^, Jassid^, Aphidid^ and Coocidje. 



In the first of these families we find the large and noisy Harvest- 

 flies or Dog-day flies (genus Cicada J. They have an oval form, with 

 the body enclosed in a firm, shelly crust, head as broad as the thorax, 

 protruding eyes, with three distinct ocelli between them, and the an- 

 tennae are short and awl-shaped or end in a sharp-pointed bristle. The 

 feet are three-jointed; wings large and glassy; abdomen of the females 

 bearing an ovipositor which rests in a fissure on the under side of the 

 abdomen, and is adapted for sawing and boring into hard wood. The 

 males have a most ingenious musical apparatus for producing the deaf- 

 ening buzzing or "drumming " with which our shade trees and groves 

 resound from early summer until autumn. These instruments are little 

 membranous sacs, which are gathered into fine plaits and fit over cavi- 

 ties at the base of the abdomen. The sound is produced by rapid 

 expansion and contraction, by means of strong muscles within that 

 part of the body. 



The most interesting of these insects is the Periodical or Seventeen- 

 year Cicada, or "Locust " — incorrectly so-called — (Cicada septemdecim, 

 Linn.) see Fig. 42, which enjoys the distinction of being the longest- 

 lived insect known to entomologists. The perfect cicadas are of a dark 

 brown or black color, with red eyes and glassy, orange-veined wings, 

 beneath which are situated the " drums," whose sound is thought by 

 some to be the word " Pharaoh," very much prolonged. 



These singular insects appear in the same locality only once in 

 seventeen or thirteen years — the development in the Southern States 

 being somewhat more rapid than in the Northern States. Their life, 

 as perfect insects, is comparatively brief, lasting not more than five or 

 six weeks. The females saw numerous consecutive, longitudinal slits 

 in the branches of fruit and forest trees, often severely injuring the 

 trees in the process. The young hatch in the course of a few weeks 



