332 



A COURSE ON ZOOLOGY. 



FlG. 293. 



CICADA. 



order to prepare a place for the eggs. At the base of 

 the abdomen of the male is an apparatus by which he 

 can produce the monotonous sound so 

 well known in summer, and that 

 some species continue day and night. 

 The larvae of the cicada drop to the 

 ground and bore their way into the 

 soil, remaining a long number of years, 

 sucking the juices of roots. This 

 insect is commonly known in the 

 United States as the seventeen-year 

 locust. 



The neuroptera have four mem- 

 branous wings, whose nervures form 

 a net-work somewhat resembling the 

 veins of a leaf. They are sometimes 

 made a suborder of orthoptera. Prominent among 

 them are the dragon-fly, whose larvae are aquatic and 

 very voracious, feeding even on newly -hatched fish ; 

 there are a large number of species. The ephemera 

 constitute a genus of neuroptera whose perfect insect- 

 life lasts but a day : the best example is the May-fly, 

 whose pupa leaves the water with wings, but still en- 

 veloped in a delicate robe, of which the insect disen- 

 cumbers itself on some stem of grass or twig. 



The coloring matter called cochineal consists of the 

 bodies of a species of hemiptera ; we will study the 

 insect in the next chapter. Ordinary lice belong to the 

 hemiptera. 



The hymenoptera include bees, humble-bees, wasps, 

 and ants, We will defer the study of bees until we con- 

 sider the useful invertebrates. The humble-bees form 

 a distinct genus, and comprise several species, some 



