324 APHIDS OF THE ROCKY MOUNTAIN REGION 
Type. U.S.N.M., No. 41945. Paratypes, Colo. Agr. Exp. Sta. Collection. 
Chief Distinguishing Characters. Brown to black body with cauda, anal 
plate and entire cornicle black, peculiar shape of the cornicle and long extent 
of the reticulated area (more than half of the length of cornicle, rather numer- 
ous convex sensoria on III (24-33 on alate and 18-28 on apterous vivipara), short 
length of cornicle (not exceeding length of cauda) and length of unguis (not 
exceeding length of III). 
Macrosiphum sibiricum (Mordvilko) 
Acyrthosiphon (Microlophium) sibiricum Mordvilko, 1914:224 and 226. 
Macrosiphum schranki Theobald, (misidentification), Gillette and Palmer, 1934::195. 
Apterous Summer Vivipara. Pale green, to yellowish or pinkish, with dark green stripes 
on median line; cauda and anal plate pale; cornicle and rostrum pale with dusky tip; legs pale 
with tips of tibiae blackish; antenna pale to tip of III then brownish to dusky. Body length 
3.3-3.8; across eyes .60; hind tibia 2.6-2.9; antenna 4.6-5; rostrum attaining 3d coxa. Hairs 
blunt to slightly capitate; on side of abdomen .02-.03. Cornicle slender, imbricated, with about 
2 rows of indistinct striae just before flange. Cauda tapering, acute, bearing 3 pairs of lateral 
hairs and a single preapical one. 
Alate Vivipara. (Mounted on slide), dark parts are as follows: Traces of lateral areas 
on abdomen in some, entire cornicle, antenna beyond base of III, rostral III and IV+-V and 
tibiae especially at tips. Cauda and anal plate pale. Otherwise as in apterous vivipara. 
Ovipara. Apterous. Pale green, some with tinge of pink and with dark green median 
line; antenna pale with tips of III, IV and V and entire VI blackish; hind tibia and cornicle 
pale with blackish tips, cauda and anal plate pale. Body length 2.90; antenna 4.2, III .95, 
IV .85, V .70, VI .18+1.35, sensoria 2-6 on III; hind tibia 2.5; proximal third slightly swollen 
and rather sparsely covered with scattered sensoria. 
Male. Apterous. Sordid yellowish or pinkish with middle dorsal portion of meso- and 
metathorax and abdomen anterior to cornicles blackish; tibiae brownish with black tips; 
cauda and anal plate sordid yellow. Body length 1.5-2; antenna 3.2-4; cauda .17 on median 
line. Oe 08 : — ee ae 
(85-405) 
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Fig. 388. Macrosiphum sibiricum 
Collections. On leaves and stems of Urtica gracilis. Throughout region. 
Apterous summer viviparae May 24 to Oct. 26, alate viviparae June 24 to July 
24 and Sept. 10, oviparae Sept. 10 to Nov. 7, males Sept. 10 to Oct. 27; rather 
common. 
Chief Distinguishing Characters. Pale green or pinkish body with darker 
median stripe, and pale appendages, slender cornicle lacking definite reticula- 
tions, short cauda with only 3 pairs of lateral hairs, long antennal IV (about 
equal to III), rather few sensoria on III (20-32), length of hairs on hind tibia 
(shorter than .04-.06), presence of sensoria on III, IV and V in male antenna, 
and apterous condition of male. 
Macrosiphum solanifolii (Ashmead) 
The Potato Aphid (Plate VIII) 
Siphonophora euphorbiae and S. euphorbicola Thomas, 1877:6. 
Siphonophora solanifolii Ashmead, 1882:92. 
Nectarophora asclepiadis Cowen (in Gillette and Baker), 1895:123. 
Nectarophora heleniella Cockerell, 1903a:168. 
