SUBFAMILY APHINAE 145 
and vertex pointed, .015 long, sparse; on hind tibia drooping, .02-.03 long. Lateral tubercles 
very broad and shallow. Cauda hardly evident, tapering, broader than long, bearing numerous 
fine hairs on each side. 
Collections. On Symphoricarpos occidentalis, on leaves during summer, on 
roots in winter and spring (fundatrices). Colorado: Fort Collins, Bellvue, and 
Cedaredge. Utah: Logan Canyon, Cowley, Daniels and Blacksmith Fork Can- 
yons. Fundatrices May 31, apterous summer viviparae May 28 to June 16, 
alate viviparae May 28 to July 8; rare; usually found associated with Brevi- 
coryne symphoricarpi. 
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Areas 30 =Alate2.0-30 
Heel St EGTA | "1 
Co:\ |, 30 yy Ny aos 
AZ 
70), y) - 
The genus Cedoaphis was erected by Oestlund (1922:127) for this species 
on account of the peculiar lateral tubercles. Tubercles of this appearance, 
however, are also found in occasional species of widely separated genera, and 
accordingly do not seem to represent a generic complex. 
Cotypes. Oestlund’s specimens determined as Aphis symphoricarpi Thomas 
Univ. of Minn. Collection. 
Aphis infrequens Knowlton 
Aphis chrysothamnicola var. infrequens Knowlton, 1929c:38. 
Aphis infrequens, Knowlton and Smith, 1936g:778. 
Apterous Summer Vivipara. Antennal I and II dusky; tips of appendages, cornicle, 
cauda, tarsi and rostral III, IV and V blackish. Body length ‘1.55’’-2; across eyes .45; hind 
tibia .87-.97; hind tarsal II .12; rostrum attaining to abdominal IV or V. 
Alate Vivipara. Head and thorax black; abdomen green with black markings; antenna, 
tarsi, cornicle, cauda and tips of tibiae dusky to black. Body length 1.50-‘‘1.75’’; across eyes 
.48; antenna 1.08-1.14; hind tibia 1; hind tarsal II .12; rostrum attaining abdominal III. 
Hairs simple, fine and erect; about .03 long on vertex, antennal III and hind tibia; on side of 
abdomen .04-.05 long. 
Fig. 160. Aphis infrequens 
Collections. On Artemisia tridentata, on leaves; alate viviparae June 16 
(resting?), on Chrysothamnus parryi apterous viviparae July 8 to Sept. 20. 
Utah: Trenton, Fountain Green, Lyman and Benjamin. 
Type. U.S.N.M. or Knowlton Collection. 
This species is very close to A. chrysothamnicola, differing chiefly as fol- 
lows: Longer rostral IV+V (.27-.29, instead of .21-.23), presence of flange on 
cornicle, usual presence of sensoria on III of apterous vivipara and shorter 
cornicle (.10-.11 instead of .11-.16) in alate vivipara. However, a larger col- 
lection of alatae might show more variation in cornicle length. Length of 
