APHID PESTS OF -MAINE, II. WIEEOW FAMIEY. JJ 



Collection data are as follows: — 23-06 fin part) June 14, 

 1906. Stem mothers; 37-10 June 29, 1910, Veazie, Me. Pupse 

 numerous and some migrants just winging; 46-10, 47-10, July 

 5, 1910, Veazie. One stem mother and numerous pupae and 

 winged forms. 91-12, a single stem mother in each gall with 

 several nymphs, Orono Campus. 110-12, July 15, 1912, Orono, 

 same tree as 91-12 and probably some of the same lot. Winged 

 'forms numerous. PoyiiJiis balsainifera. 



Pemphigus populicaulis Fitch. This species is structurally 

 very close to hursariiis. A few of the galls are shown in Figs. 

 49, 50, and 51. As will be noticed these are formed near the 

 midrib and may be at the base of the leaf or elsewhere along 

 the midrib, the opening being sometimes on the ventral (Fig. 

 49) and sometimes on the dorsal surface TFig. 51). The galls 

 vary considerably in size and in shape though they are more or 

 less globular. This species is common on Populus halsamifera 

 in this vicinity. 



Winged viznparons female, — spring migrant. The wing of 

 this form is shown in Fig. 46 I. and the antenna in Fig. 27. It 

 will be noticed that joint VI is as heavily annulated as the other 

 joints. I have specimens from ]\Iinnesota and Texas which 

 accord with the ]vlaine material and the figures of California 

 specimens fEssig 1912J show the same characters as typical. . 



Fig. 27. P. populicaulis. Antenna of spring migrant. 



Collection data are as follows: — 23-11, Orono, July 6, 191: 

 Winged forms in galls. 



101-12. July 18, 1912, A'eazie. Galls on stem at base of leaf 

 (Fig. 50 j causing a twist in the stem. Opening on the ventral 

 side. Galls are more or less pinkish and some are decidedly 

 reddish. 



102-12 \'eazie, July 18, 1912, galls on ventral side of leaf 

 opening on dorsal surface, greenish or occasionally pinkish. 

 They measured from half an inch to three-quarters of an inch 

 along the mirl-rib. Fig. 51. 



