HO MO PT ERA 



407 



adults vary so much that eleven distinct varieties are now recognized ; 

 two of these are represented at b and c in Figure 475. 



The rose leaf -hopper,^ £mpoa roscB, is a well-known pest of the 

 rose. Swarms of these insects may be found, in various stages of 

 growth, on the leaves of 

 the rose-bush through 

 the greater part of the 

 summer, and their nu- 

 merous cast skins may be 

 seen adhering to the low- 

 er sides of the leaves ; in 

 fact attention is most fre- 

 quently called to this 

 pest by these white ex- 

 uviae. The adult meas- 

 ures less than 3 mm. in 

 length. Its body is yel- 

 lowish white, its wings 

 are white and transpar- 

 ent, and its eyes, claws, 

 and ovipositor are brown. 

 The apple leaf-hop- 

 per, Empoasca JahcB. — Al- 

 though this species is 

 named the apple leaf- 

 hopper, it infests to an in- 

 jurious extent many dif- 

 ferent plants, both cultivated and wild. Slingerland and Crosby ('14) 

 state that it infests apple, currant, gooseberry, raspberry, potato, 

 sugar-beets, beans, celery, grains, grasses, shade trees, and weeds. 

 The adult insect measures about 3 mm. in length, and is of a pale 

 yellowish green color with six or eight distinguishing white spots on 

 the front margin of the pronotiim. 



The genus Drceculacephala includes grass-green or pale green, 

 spindle-shaped species, in which the head as seen from above is long 

 and triangular. One of the species, D. reticulata, sometimes greatly 

 injures fields of grain in the South. 



The genus Oncometopia includes species in which the head is 



more blunt than in the preceding genus and is wider across the eyes 



than the thorax. 0. undata (Fig. 476) is a common 



species. Its body, head, fore part of the thorax, scutel- 



lum, and legs are bright yellow, with circular lines of 



black on the head, thorax, and scutellum. The fore 



wings are bluish purple, when fresh, coated with 



whitish powder. It measures 12 mm. in length. It is 



said to lay its eggs in grape canes, and to puncture 



with its beak the stems of the bunches of grapes, 



causing the stems to wither and the bunches to drop off. 



One division of this family, the subfamily Gyponinae, includes forms 



which resemble certain genera belonging to the Cercopidasby their 



Fig- 475- — Erythroneura comes: a and b, female 

 and male of the typical conies variety; c, the 

 vitis variety. (From Slingerland.) 



Fig. 476. —On- 

 cometopia 

 undata. 



