300 APHIDS OF THE ROCKY MOUNTAIN REGION 
Chief Distinguishing Characters. Green body, somewhat outward curved 
and slightly constricted cornicle with reticulated area .18-.20 long, length of 
antenna (III exceeding 1). This species falls in the M. solanifolii and M. creelii 
complex, differing from the former in the longer antenna and cornicle and 
from the latter, apparently, only in the shorter antennal IV (not longer than .75 
instead of .75-.95). Host transfer tests may prove creelii a synonym. 
Macrosiphum coweni (Hunter) 
Nectarophora artemisiae Cowen (in Gillette and Baker), 1895:123 (preoccupied.) 
Nectarophora cowent Hunter, 1901:114 (new name for N. artemisiae Cowen). 
Macrosiphum coweni, Gillette and Palmer, 1934:175. 
Apterous Summer Vivipara. Dark brown to blackish green to black; cauda and cornicle 
dusky throughout; appendages brown to blackish except base of antennal III. Body length 
1.5-2; across eyes .47; hind tibia 1.3-1.7; hind tarsal II .15-.17; antenna 2.4-3.2, III .60-.80, 
IV .40-.60, V .30-.50, VI .15-.19-+.65-.90, sensoria 3-8 on III; cornicle .55-.70, reticulated area 
.05-.10 long; rostrum acute, tip needlelike, IV-+V .16, attaining 3d coxa. Cauda elongate- 
spoon-shaped, pointed,..25-.40 on median line, .40-.50 on side, bearing 4-5 pairs of lateral hairs 
and 2 pairs of dorsal hairs. Hairs blunt to slightly capitate; on vertex, on antenna and hind 
tibia .04-.05; on side of body .04-.06; cornicle bearing 3-5 hairs. 
Alate Vivipara. Color and measurements as in apterous vivipara except as follows: 
Sensoria 15-23 on III; cauda .25 on median line, .30 on side; rostrum attaining 2d coxa. Hairs 
blunt to slightly capitate; on vertex .02-.03; on antenna and hind tibia .04-.05; on side of 
abdomen .05. 
Collections. On leaves and tips of Artemisia tridentata and A. vulgare. 
Throughout region. Apterous summer viviparae May 3 to Sept. 30, alate vivi- 
parae June 18 to July 18, oviparae Nov. 22; common. 
Type. Lost. 
Neotype. U.S.N.M. Paraneotypes, Colo. Agr. Exp. Sta. Collection. 
Chief Distinguishing Characters. Number of hairs on cornicle (3-5), 
length of reticulated area on cornicle (.08), length of unguis (generally longer, 
never shorter than cornicle), dark brown to blackish green or black body, 
rather small number of sensoria on III (3-11 in apterous and 15-23 in alate 
vivipara) and needlelike tip of rostrum. 
This species is separated from M. artemisiae (Boyer de Fonscolombe) 
(judging from specimens determined by Hille Ris Lambers and from descrip- 
tion by Theobald, 1926:161) as follows: Needlelike tip of the rostrum (lacking 
in artemisiae which has tip acute but not needlelike), length of cornicle (ex- 
ceeding length of cauda instead of shorter than cauda as in artemisiae) and 
extent of reticulation on cornicle (much less than half of cornicle instead of 
about half). 
Not figured on account of similarity to M. filifoliae. 
Macrosiphum creelii Davis 
The Alfalfa Aphid 
Macrosiphum creelii Davis, 1914a:41; Gillette and Palmer, 1934:176. 
Apterous Summer Vivipara. Pale green, darker on median line; cauda and tibiae pale 
to slightly dusky; cornicle dusky on distal half; antenna dusky on I, II and base of III, 
remainder blackish throughout; cauda pale to slightly dusky. Body length 2.3-4; hind tibia 
2-3; hind tarsal II .16-.19; antenna 4.3-5, III 1.0-1.23, IV .90-1.2, V .80-1, VI .24-.28+-1.16-1.5, 
sensoria 5-8 on III; cornicle 1.1-1.3, reticulated area .18 long; cauda .46 on median line, .50 on 
side; rostral IV+-V .13, attaining 2d coxa. Hairs slightly capitate; on vertex .03; on antennal 
III .04-.05; on hind tibia .06; on side of body .04-.05. Cauda tapering, without noticeable neck, 
4-5 hairs on each side and a single dorsal preapical one. 
Alate Vivipara. Same as apterous vivipara except as follows: Head and thorax pale 
brownish; cornicle .93-1.20; sensoria 15-21 on III. 
Collecticns. On leaves of alfalfa (Medicago sativa). Colorado: Fort Collins, 
Florissant and Masonville. Utah: Tooele. Apterous summer viviparae June 1 
to Aug. 13, alate viviparae June 14 to July 8 and Oct. 1; rather rare. 
Type. Davis Collection. 
