146 BULLETIN 85, UNITED STATES NATIONAL MUSEUM. 



After five or six days more the adult emerges, making the cycle 

 from egg to adult about one month. There are about four broods 

 each year (in New York), but they are not sharply separated. All 

 stages may be found on one tree from June to September. In general, 

 however, the greatest numbers are present at intervals of about one 

 month. The adults emerging in September are usually the hiber- 

 nating winter forms. For further details on the life history and other 

 phases of tliis species, consult Slingerland '92: or '96, from which 

 source most of the above statements have been derived. 



PSYLLA HARTIGII Flor. 



Figs. 130, 145. 



Psylla hartigvi Flor '61: 469.— Loew '77: 130; '79: 577; '82: 240; '88: 18.— Reuter 

 '81: 150.— Scott '82: 253.— Edwards '96: 244.— Sulg '05: 3; '10b: 

 24; '10c: 26 (pi. xii).— Oshanin '07: 358. 



Psylla hartigii (?) Patch '12b: 222. 



Psylla sylvicola Lethierry '74: 90. — Scott '76: 539. — Douglas '76: 68. — Edwards 

 '96: 244. 



Length of body (male) 2 to 2.5 mm; (female) 2.8 to 3.2; length of 

 forewing 3.3; width of head 0.89. General color greenish yellow to 

 orange yellow; antennae black distally. 



Vertex rather long down the center, fully half as long as broad, 

 emarginate in front at median hne, with two fovese discally as usual; 

 genal cones nearly as long as vertex, rather stout, roundly acute at 

 apex, pubescent; antennae one and three-fifths to two times as long 

 as width of head. 



Thorax arched, typical in form. Legs rather slender; hind tibiae 

 with basal spur wholly wanting. Wings slightly tinged with yellow, 

 especially in apical half, venation typical; pterostigma large. 



Genitalia. — Male. — Anal valve long, sides subparallel, truncate at 

 apex, pubescent; forceps much shorter than anal valve, rather 

 slender, somewhat constricted a little beyond midpoint, terminating 

 in a blunt, sHghtly bifid apex, pubescent. Female. — ■Genital segment 

 very elongate and slender, longer than rest of abdomen, dorsal 

 valve a little longer than ventral and conspicuously curved 

 downward. 



Described from six males and females in balsam (some of the speci- 

 mens used by Miss Patch in her description '12b: 222), from Orono, 

 Maine, on birch (Betula 'populifolia) ; these were loaned by Miss Patch. 

 Also, several females from" Liue," Europe determined by Sulc as P. 

 Jiartigii. 



The distribution in Europe is as follows : Great Britain, Germany, 

 Austria, Finland, Russia (Oshanin '07: 358). Sulc reports its host 

 plant in Europe to be Betula alba. 



