SUBFAMILY ERIOSOMATINAE 37) 
Apterous Vivipara. Pale straw-yellow, brown on head, intersegmental dots and dorsal 
bands on abdominal VI, VII and VIII; appendages brownish. Body length 1.5-2; hind tibia 
.35-.40; hind tarsal II .10-.12; antenna .45 four- or five-segmented; rostrum surpassing 2d 
coxa. Hairs usually fanlike, bent, squamous, rarely simple, .02-.03 long; cauda minute; anal 
plate large and rectangular. 
Alate Vivipara. Same as apterous vivipara except wing 2.45, hamuli 4 in number and 
antenna five- or six-segmented. 
Collections. On roots of Echinochloa crusgalli and other grasses, Artem- 
isia sp., Juncus sp. and ants’ nests. Throughout northeastern part of Colorado 
from Boulder to Cherokee Park and Virginia Dale. Apterous viviparae Feb. 17 
and April 3 to Aug. 30; rather rare. 
Mordvilko (1935:202) reports the primary or winter host to be Pistacia on 
which it causes leaf galls. Pistacia does not occur in North America and the 
aphid remains on the summer or secondary host throughout the year. 
Genus Trifidaphis Del Guercio 
Trifidaphis Del Guercio, 1909b:332. 
Tullgrenia van der Goot, 1912:96. 
Characters. Antenna five-segmented in aptera, five- and six-segmented in 
alata; II decidedly longer than I; secondary sensoria round to oval; permanent 
sensoria without cilia. Hairs simple; numerous and rather conspicuous. Corn- 
icle lacking. Cauda semilunar; anal plate rectangular and large. Fore wing 
with media simple; hind wing with both media and cubitus. 
Genotype (fixed by Del Guercio, 1909), Pemphigus radicicola Essig. Only two, 
doubtfully distinct, species represented in region. 
Trifidaphis phaseoli (Passerini) 
Tychea phaseoli Passerini, 1860:39. 
Tullgrenia phaseoli, van der Goot, 1915:514. 
Trifidaphis phaseoli, Theobald, 1929:208; Gillette and Palmer, 1934:240; Mordvilko, 
1935:183. 
Apterous Summer Vivipara. Pale pinkish yellow or flesh color with head, pronotum and 
tip of abdomen brownish; powdery; appendages brownish. Body length 1.5-2.7; globose; hind 
tibia .40-.50; hind tarsal II .13-.15; antenna .50-.58; rostrum nearly attaining 3d coxa. Hairs 
simple and numerous; on hind tibia and body .03-.04. 
) 10 =. eae 
[Psartee, i 
F-- Anal Plate-""') 
Sear long eo 
— 8M ental Plate 
DE 
Fig. 453. Trifidaphis phaseoli 
Alate Vivipara. Head and thorax black; abdomen olive-green to olive-brown, abdominal 
VI, VII and VIII with dark dorsal dashes; appendages blackish; stigma dark on posterior 
border. Body length 2.3-2.7; hind tibia .60-.80; antenna .75-.80; rostrum attaining 2d coxa; 
fore wing 2-2.9 long; hamuli 2-4 in number. Hairs simple and numerous; body .02-.03; cauda 
very small. Anal plate large and rectangular. 
Collections. On roots of cultivated beans, potato, parsnip, Euphorbia sp., 
and Galium sp. Throughout region. Apterous viviparae June 6 to Nov. 10, 
alate viviparae July 22 to Sept. 28; not common. 
Genotype Trifidaphis radicicola (Essig) 
Pemphigus radicicola Essig, 1909a:9. ; 
Trifidaphis radicicola, Essig, 1910a:283; Swain, 1919:141. 
Characters. Similar to T. phaseoli, indeed the writer has been unable to 
establish any distinguishing characters. The type specimen of alate vivipara 
had five-segmented antenna, but Swain (op. cit.) states both five- and six- 
