SUBFAMILY APHINAE 191 
wing with radial sector but slightly curved. Hairs pointed and inconspicuous. 
Genotype, (monotypical), Aphis stellariae Hardy. 
Key to Species of Brachycolus 
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Brachycolus holci Hardy 
Aphis holci Hardy, 1850:531. 
Brachycolus holci, Buckton, 1879:147 (in part). 
Brachycolus stellariae (Hardy), (misidentification), Gillette and Palmer, 1932b:460. 
Holcaphis holci, Hille Ris Lambers, 1939:99. 
Apterous Summer Vivipara. Pale yellowish or greenish with dusky parts as in alate 
vivipara. Body length 1.8; hind tibia .45; antenna .63; rostrum, hardly attaining 2d coxa. 
Alate Vivipara. (Cleared and mounted), head and thorax dark; abdomen immaculate; 
appendages, cauda and anal plate dusky. Body length 1.30; hind tibia .60; hind tarsal II .15; 
antenna .70-.80, secondary sensoria convex. Hairs pointed, very sparse and inconspicuous. 
Cornicle slightly raised, truncate, without flange. Cauda tapering, rather blunt, bearing 2 hairs 
on each side and 1 or 2 preapical ones. 
Ovipara. Apterous. (Mounted in balsam), head dark; body without marking; dusky 
soo Jl Sen o— 
19-22 5en.4-6 
| Fig. 221. Brachycolus holci 
parts as in alate vivipara; with hind tibia slightly swollen on proximal half and bearing rather 
numerous sensoria. 
Collections. On grass. Colorado: Fort Collins and Boulder. Apterous sum- 
mer viviparae Aug. 19, alate viviparae May 31 and June 3, oviparae Nov. 20; 
apparently rare. 
Description and figures from specimens determined by Hille Ris Lambers. 
[Genotype Brachycolus stellariae (Hardy) ] 
Aphis stellariae Hardy, 1850:788. 
Brachycolus stellariae, Buckton, 1879:147; Theobald, 1927:313; Hilie Ris Lambers, 
1939 :97. 
Apterous Summer Vivipara. (Cleared and mounted), body immaculate; head dusky; an- 
tenna, cauda, anal plate, tarsi, tips of tibiae and of rostrum dusky. Body length 1.4; hind tibia 
.50; hind tarsal II .12; antenna .80, III .15-.19, IV .08-.10, V .09-.11, VI .08+.23-.25; cornicle 
.02, rostral IV+V broad, .07 long, attaining 2d coxa; cauda tapering, with 2 pairs of lateral 
hairs, .08 long on median line, .12 on side. 
Alate Vivipara. (Cleared and mounted), head and thorax dusky; abdomen immaculate; 
appendages, cauda, anal plate and distal portion of rostrum dusky. Body length 1.30, hind tibia 
.70-.73; hind tarsal II .12; antenna 1.10-1.20, III .28-.33, IV .18, V_ .15-.19, VI .10+.26-.37; 
cornicle, on abdominal V according to Hille Ris Lambers (op. cit.), .03 long; cauda .08 on 
median line, .12 on side, with 2 pairs of lateral hairs and one dorsal preapical one. 
Host. On leaves of Stellaria sp., causing distortion of leaf tufts. (Not taken 
in region.) . 
Data for above description obtained from study of specimens determined by 
Hille Ris Lambers and from description by Theobald (op. cit.). 
Brachycolus tritici Gillette 
The Western Wheat Aphid 
Brachycolus tritici Gillette, 1911a:441; Gillette and Palmer, 1932b:461. 
Apterous Summer Vivipara. Head dusky; rest of body pale yellowish to greenish; heavily 
powdered; distal half of antenna, most of rostrum, legs, cauda and anal plate dusky to black- 
ish; cornicle usually slightly dusky. Body length 1.15-1.88; hind tibia .43-.55; antenna .59-.70; 
rostral IV-+V long, slender, attaining 2d coxa. 
Alate Vivipara. Head and thorax black; abdomen pale yellowish to pale green; slightly 
powdery; wing veins black; antenna except proximal part of III, tarsi, tips of tibiae, cauda 
and anal plate black; cornicle yellowish or brownish. Body length 1.3-1.5; hind tibia .55-.65; 
