SUBFAMILY APHINAE 105 
~~ 
6. VI with unguis 1.6-2 times base and equalling length of cornicle (p. 105).................... bicolor 
.. VI with unguis 1-1.5 times base and shorter than cornicle (p. 108)...................- populifoliae 
famcormicie large, equalling hind tarsal IT in length) (p. 107) c2--6-ccc..--0cccccstecascn-nesteeea-es- tlocculosa 
wee COrnicle minute, much shorter than hind tarsal, TT €pi 0G) corso. ..cccc epee ceceeeeneve voc ev saves -eeee= braggil 
Sa RMI Moh ats PO p= Ov LONE Parl OG \ecetececteatvnttecc-accescsec he cne eee cl eit ote, eo ee pseudopopulea 
Siti aiiates es) O=920) Longe Dal 07.) castae ceececce tak tee eae ae ee rn Oe St Oe pilosa 
Pterocomma beulahensis (Cockerell) 
Cladobius beulahensis Cockerell, 1904:263. 
Pterocomma beulahensis, Baker, 1916a:282; Gillette and Palmer, 1931:928. 
Fundatrix. Body length 3.5;-hind tibia 1.6; antenna 1.5. 
Apterous Summer Vivipara. Yellowish olive-green. Body length 3-4; hind tibia 1.9-2; 
antenna 1.9-2. Hairs fine; on vertex and body .08-.10 long. 
Alate Vivipara. Same as apterous vivipara in measurements and color; wings hyaline. 
Rostrum hardly attaining 3d coxa. Cornicle slightly swollen to cylindrical. 
Alate Viv. 
Fig. 113. Pterocomma beulahensis 
Collections. On Populus tremuloides, on bark and twigs. Colorado: Fort 
Collins, Pingree Park, Idaho Springs, Manassa, and Lost Lake. New Mexico: 
Beulah. Utah: Generally in northern half of the state. Idaho: Mink Creek and 
Emigration Canyon. Fundatrices June 11, apterous summer viviparae June 13 
to July 5, alate viviparae May 26 to Aug. 4; rather rare. 
Cotypes. U.S.N.M. 
Chief Distinguishing Characters. Length of unguis (usually longer than 
half of III and 1.25-1.5 times length of cornicle), shape of the cornicle (dis- 
tinctly swollen to practically cylindrical) and host plant. 
Pterocomma bicolor (Oestlund) 
The Reddish Brown Willow Bark Aphid 
Melanoxanthus bicolor Oestlund, 1887 :36. 
Pterocomma bicolor, Baker, 1916a:284. 
Clavigerus bicolor, Gillette and Palmer, 1931:932. 
Fundatrix. Same as apterous summer vivipara except for the shorter unguis, about .18, 
not longer than base of VI. - 
Apterous Summer Vivipara. Young. Pale greenish. Adult. Reddish brown to dusky 
greenish yellow, with slight powdery markings on intersegmental lines; legs, cornicle, and 
antenna yellowish. Body length 3.0-4.0; hind tibia 1.5-2.0; hind tarsal II .20-.22; antenna 
1.5-2.0, III .40-.50, IV .25-.30, V .25-.29, VI .12-.18-+.24-.30; cornicle .25-.30. Rostrum attaining 
between 2d and 3d coxae. 
Ti Rae raceme 
‘ x ale , 18, 24-230 
{e) ts Peony \ vy 7 ) + » 
Bes ta ee VM AY yy) yews , 
.25- .30 Hpaeay ear ats) 
Fig. 114. Pterocomma bicolor 
Alate Vivipara Color and measurements same as apterous vivipara or slightly longer. 
Wings hyaline. 
Hairs fine, numerous; on vertex and body .10 long; on hind tibia .10-.12 (diameter of 
tibia .06). Cornicle 4 times as long as wide, somewhat swollen in distal half, very slightly 
imbricated, flange distinct. Rostral IV-+V .17-.18 long, hardly attaining 2d coxa. Lateral 
tubercles well developed. = 
Ovipara. Greenish olive-brown. Measurements same as in vivipara. Hind tibia only 
slightly swollen and bearing numerous small sensoria on proximal half. 
Male. Alate. Color same as in alate vivipara. Body length 2.30; antenna 1.80; numerous 
small sensoria on III, IV and V. 
