CLASS INSECTA: OBDEE HEMIPTEEA. 219 



Fig. 375. 



Dytiscus fasciventris, Water-beetle and Larva of Water-beetle. " Water-tiger." 



crawl upon the land, construct a round cell, and come forth 

 as beetles. 



ORDER HEMIPTERA. 



General Characteristics. The Heraipters (half- winged) 

 have fore wings half leathery and half membranous ; usually 

 both ocelli and compound eyes ; and a suctorial mouth. The 

 metamorphosis is incomplete. 



Cicadidae. The Harvest-fly family includes the "Seven- 

 teen-year Locusts." * The females, with a saw-like oviposi- 

 tor, furrow the twigs of both forest and orchard trees longi- 

 tudinally to the length of fifteen or eighteen inches, piercing 

 every two-thirds of an inch to the pith, and depositing two 



* They appear in different localities annually, but in any one only once in seven- 

 teeu years. C. V. Riley states that there is a " Thirteen-year Locust." 



