356 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 2 



ialsamifera at Lynn, Mass,. June 27. Sensor ia : Joints three, 20 to 25 ; 

 four, 6 to 8; five,. 6 to 7; six, 5 to 7. Fig. 12. Drawing from Colo- 

 rado specimens. 



This louse is of occasional occurrence in Colorado upon the broad 

 leaved cottonwoods. The upper surface of the leaf folds together 

 along the line of the midrib and the sides puff out like a well filled 

 purse.- 



Pemphigus popuUmonilis Riley. Not noticed east, but was very 

 common upon terminal leaves of Populus tridiocarpa about Portland, 

 Oregon. Many of the little pockets were dissected and in some 

 syrphus larvae were seen, but in others were the living lice, one in a 

 gall. All acquire wings. Apparently the young migrate from the 

 gall almost as soon as born and start a home of their own by the irrita- 

 tion that their beaks produce in the growing leaf. This species is 

 extremely abundant upon young narrow-leaved cottonwoods (P. an- 

 gustifoUi) in Colorado. Sensoria: Joints three, 6 to 9 ; four, 3 to 5; 

 five, 1 to 3 ; six, 1. Fig. 13. From Colorado specimens. 



Pemphigus vagabundus Walsh. A single gall, quite immature, was 

 taken from cottonwood at Rochester. 



This species is comparatively rare in Colorado, but occasionally a 

 small tree is quite badly infested. The antenna has a very long unguis 

 for this genus and what is more remarkable the unguis seems to have 

 three sensoria. See Fig. 12. Sensoria as follows: Joints three, 10; 

 four, 2; five and six, 1 each; unguis 3. From alate lice taken at 

 Chicago, 111., by J. J. Davis, and at St. Louis, Mo., by J. T. Monell, 

 Fig. 14. 



Schizoneurinae 



Schizoneura lanigera Hausm. This species, almost universally 

 present in apple orchards, was not specially searched for but was 

 noticed at Geneva, Central Park, Washington and Lawrence, and was 

 nowhere very abundant. This is one of the most serious and gen-, 

 eralh^ distributed insect pests of apple orchards in Colorado. Mr. 

 Bragg found the alate pre-sexual form at Lawrence. So far as I know 

 this is the earliest date for the alate form. Mr. George P. Weldon re- 

 ported an alate louse of this species at Austin, Colorado, July 15, 1909. 

 Figure 15 shows an enlarged antenna. 



Schizoneura ulmi L. (americana Riley). Many alate lice and 

 nymphs in rolled leaves of American elm at Geneva, Albany, Law- 

 rence and Wood's Hole. The curled leaves were also seen at Wash- 

 ington and Georgetown, and on European elm (Uhnus campestris) at 

 Corvallis. This louse is a real pest upon white elm nearly everywhere 

 that this tree is grown in Colorado. The antenna is shown in Fig. 1 6 



