354 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 2 



spruce to go to the red spruce, but only about 50 i^er cent, of the form 

 (var coiveni.) on red spruce migrate to the blue spruce each June. 



Phorodon humuli and Hyalopterus arundinis winter upon the plum 

 and leave in early summer for herbaceous plants, but we have found 

 occasional colonies of both these species continuing throughout the 

 summer on plum foliage ; P. humuli is known also to spend the entire 

 year upon the hop. Aphis hakeri uses the apple and the thorn (Cror 

 fegus) as its winter hosts and the clovers for its summer food plants, 

 but we find it remains commonly upon red and white clovers through- 

 out the year in protected places, and occasional late summer colonies 

 have been found upon apple sprouts. Other similar cases might be 

 added to the list. Fig. 3. 



Hormaphis hamamelidis Fitch. The smooth cone-shaped galls of 

 this species were taken in great numbers upon leaves of witch hazel 

 at Washington, Webster^ and Wood's Hole. The galls contained one 

 stem-mother and in each ease examined many of her offspring in all 

 stages of growth including adult winged examples. In color these lice 

 resemble those in the spiny galls of the preceding species. Fig. 4, 5. 



Pemphigus hetae Doane. Taken at Salem, Oregon, where it was 

 common upon roots of Chenopodium album in an apple orchard. Ap- 

 terous form and pupte were seen, but none that were alate. 



Tliis is a serious sugar beet pest in Colorado occurring upon the 

 eastern and western slopes. So far as I can learn this species does 

 not occur much east of the eastern line of Colorado. We find the. 

 native asters and golden rods {Aster and Solidago sp.) favorite host 

 plants, while it is also common on the roots of Chenopodium and Iva. 

 Sensoria on antennal joints about as follows : three, 6 to 7 ; four^ 2 ; 

 five and six, 1 each. See fig. 6. 



Pemphigus fraxinifolii Riley. This louse is very common upon white 

 ash in Colorado, but we did not meet with it anywhere east of Colo- 

 rado. I found the louse and its injuries very common upon the native 

 ash (Fraxinus oregona) about Portland, Oregon. It seemed specially 

 abundant upon little trees that were but a few feet high, tightly curl- 

 ing the leaves, many of which were dead. Sensoria : joints three, 5 to 

 7 ; four, 4 to 5 ; five, 5 to 6 ; six, 2 to 3. Fig. 7. 



Pemphigus acerifolii Riley. Mr. Harley Wilson showed me this 

 species at Georgetown on silver maple {A. dasycarpum) . The lice had 

 nearly all left the folded leaves which they had inhabited, and the 

 leaves had ripened and fallen. Some large trees had been badly in- 

 fested. This is a very large species, measuring as much as 4.50™™ in 

 body length and spanning fully 10™™ from tip to tip of wings. The 

 antenna is very short, barely exceeding 1™™. and the sensoria are con- 



