108 APHIDS OF THE ROCKY MOUNTAIN REGION 
Apterous Summer Vivipara. Pale green, spotted with darker green in two longitudinal 
rows, head, pro- and mesonotum, dorsal bands and lateral areas on abdomen, appendages, 
cauda and anal plate black; cornicle pale to dusky. Body 2-3 by 1.06-1.60; antenna 1.06-1.50; 
cornicle .20*. Whole insect pilose; hairs fine on body and vertex .08-.12 long; on antenna 
erect, numerous, length 2-3 times diameter of III; on hind tibia erect, numerous, .10-.15, about 
twice as long as diameter of tibia. 
Alate Vivipara. Head and thorax pale ferruginous brown; abdomen ashy gray with 
broad brown bands and lateral areas on each segment; appendages pale brown to black. Body 
3.04-3.60 by 1.06-1.50; antenna 1.77, unguis hardly longer than base of WI; cornicle cylindrical, 
.20*. Rostrum attaining beyond 3d coxa. Body and appendages hairy. Hairs fine, numerous; 
on body and vertex .12-.16 long; on antennal III erect, length about 3 times the diameter of 
III; on hind tibia 2-3 times as long as diameter of tibia. Wings long and pointed and curved 
inward on costal and apical margins; cauda not projecting beyond anal plate. 
Host. On bark of twigs of Salix sp. (Not recorded from region.) 
Data for above description taken from description and figures by Buckton 
(op. cit.) and from specimens determined by Hille Ris Lambers. The figures 
were drawn from the latter. 
Pterocomma populifoliae (Fitch) 
The Reddish Brown Poplar Aphid 
Aphis populifoliae Fitch, 1851:66. 
Pterocomma populifoliae, Baker, 1916a:280; Gillette and Palmer, 1931:933. 
Fundatrix. Same as apterous summer vivipara except the shorter unguis, about .17, not 
longer than base of VI. 
Apterous Summer Vivipara. Reddish brown to dusky greenish yellow, with slight pow- 
dery markings on intersegmental lines; cornicle and appendages yellowish with distal ends of 
segments and tarsi black. Body length 3-4; hind tibia 1.5-2; hind tarsal II .20-.24; antenna 
2-2.25. Hairs fine, numerous; on vertex and body .10-.12; on hind tibia .07-.13 (diameter of 
tibia .09). Cornicle moderately swollen. 
; ih) 1B A.22 
Alate Wiv. Fundatrix =Aptviv! ) JE Se 
ornicles C96 =a 
Z2 . 
2 4 a = 
ATK , Ne 
Alate Viv on Populus ete 
Fig. 118. Pterocomma populifoliae 
Alate Vivipara. Color and measurements same as in aptera. Wings hyaline. Rostral 
IV+V .16-.17, attaining between 2d and 3d coxae. 
Ovipara. Apterous. Same as apterous summer vivipara except hind tibia the proximal 
seven-tenths of which is distinctly swollen and thickly covered with numerous small tubercu- 
late sensoria. 
Male. Alate. Similar to alate vivipara except the antenna which bears numerous sensoria 
on Lita VeandsVi 
Collections. On bark of Populus angustifolia, P. tremuloides and P. sp. 
Colorado: Fort Collins and Manassa. Utah: American Fork Canyon, Hyde Park, 
Mount Nebo, Morgan and Indian Canyon. Wyoming: Centennial. Fundatrices 
April 18, apterous summer viviparae April 25 to June 8, alate viviparae May 8 
to June 8 and Oct. 10, oviparae Oct. 27, males Oct. 30; very common. 
Cotypes. U.S.N.M. 
Chief Distinguishing Characters. Shape of cornicle (moderately swollen 
on distal half) and length of cornicle (.33-.40, longer than unguis). 
*Buckton gives the length of the cornicle in apterous female as .12 and in alate female 
as .38. Surely there is some error here. In all other characters the specimens sent by 
Hille Ris Lambers agree reasonably well with Buckton’s description. 
