24 BULLETIN 805, U. S. DEPARTMENT OF AGRICULTURE. 



Summer eggs. — Smnmer eggs are laid by first-brood adults during 

 July in the veins of the lower leaves. 



The Nymph, 



The njTnphs of this species differ from those of Empoasca mali 

 hy their paler color, by their smaller size, and by the fact that they 

 confine their activities entirely to the lower leases of the trees. 

 Though very active they are not quite as quick in their movements 

 as the nymphs of the apple leafhopper. 



As the young nymphs emerge from the eggs in the bark they make 

 their way to the nearest leaves, where they immediately settle down 

 to feed. In the vicinity of West Chester, Pa., the first nymphs of the 

 season emerge about May 1, and by May 15 practically all the winter 

 eggs have hatched. Generally speaking, the nymphs of this species 

 are from three to four weeks old before the first nymphs of Empoasca 

 mali ajjpear on the terminal leaves. 



The Adult. 



Nymphs of the first brood transform to adults during the first 

 two weeks in June and these adults feed on the foliage for several weeks 

 before mating. Oviposition extends over a period of about two 

 weeks during late June and early July, most of the first-brood adults 

 dying by the end of July. 



Second-brood a,dults begin to appear during the first week in August, 

 and they remain on the trees until death, which occurs by Novem- 

 ber 1, after the winter eggs have been deposited. A few adults 

 have been noticed on the trees as late as November 25. No rose 

 leafhoppers, either in confinement or in the field, were observed to 

 hibernate in the adult stage. 



First Generation, 

 first brood of eggs. 



The length of the incubation period of the first-brood eggs (i. e., 

 the winter eggs) is 6 to 7 months. Eggs deposited during October 

 hatch by the middle of May of the following year at the latest. 



FIRST BROOD OF NYMPHS. 



Nymphs newly hatched from winter eggs were confined in indi- 

 vidual cork cages on uninfested leaves. The average length of the 

 entire nymphal period, as indicated in Table XIV, was 33.4 days; 

 the maximum, 36 days; the minimum, 30 days. 



