SUPERFAMILY JASSOIDEA 



107 



tion are the terminal segments, inekuling tlie genitalia. In 

 the female the last ventral segment is frequently of a par- 

 ticular shape or structure for dift'erent species and in many 

 groups is of the greatest service for description. It is fol- 

 lowed by the sheaths of the ovipositor, this latter being a 

 narrow, saw-like pair of blades, extending to the tip, some- 

 times considerably beyond the tip of the sheaths. The 

 males have a terminal segment beneath a modified segment, 

 called the vah'e, which is followed by two movable pieces 

 called plates. Above these, forming the sides of the last 



Fig. 6.3. — The clover leafhopper (Agallia sanguinolenta): a, adult; h, 

 nymph, side view; c, nymph, dorsal view; d, face; c, elytron; /, female 

 genitalia; g, male genitalia. All enlarged. (After Oshorn and Ball.) 



segment, are the pygofers. A ready understanding of these 

 various parts will be helped by a study of the accompanying 

 figure, in which they are located and named. For the 

 different stages of insects the usual terms egg, larva, or 

 nymph, ])upa, and adult are used, as these are sufficiently 

 definite in indicating the steps of development from the 

 egg to the mature form. 



Bythoscopidse. — The Bythoscopidcp include forms whicli 

 are for the most part found upon trees or woody plants, 

 sometimes in great abundance and which doubtless occasion 

 considerable injury, although the eft'ect in any particular 



