308 APHIDS OF THE ROCKY MOUNTAIN REGION 
Chief Distinguishing Characters. Short cornicle (hardly longer than cauda), 
_comparatively long reticulated area (over half the length of cornicle), glaucous 
green body with black cornicle and dusky cauda and anal plate, number of 
sensoria (14-17 on III of alate vivipara, 2-6 in apterous vivipara), length of 
unguis (2-3 times as long as cornicle) and slightly swollen proximal third of 
hind tibia which bears only about 14 sensoria. 
Macrosiphum gaurae Williams 
Nectarophora sp. Cowen (in Gillette and Baker), 1895:124, line 14. 
‘Siphonophora gaurae Williams, 1910:79. 
Macrosiphum gaurae, Davis, 1911b:29; Gillette and Palmer, 1934:181. 
Fundatrix. Same as apterous vivipara except as follows: Body length 2.10; hind tibia 
1.60; antenna 2; cornicle .58-.60 with reticulated area .10; cauda .35 on median line, .40 on side 
and bearing 3-4 lateral pairs of hairs; rostral IV+V .15. 
Apterous Summer Vivipara. Pale yellow-green or mottled pink with head yellowish; 
cornicle pale with dusky tip. Antenna dusky beyond near tip of III; legs, cauda and anal 
plate pale. Body length 2.8-3.3; across eyes .52-.56; hind tibia 2.2; antenna 2.5-3.4; rostrum 
surpassing 2d coxa. Hairs slightly capitate; on side of abdomen .03-.04. Cauda tapering, 
without constriction bearing 4-5 pairs of lateral hairs 1-2 dorsal preapical ones. 
puree 
Hd, eee (.52 -.66) (sen 1-3) (22-.28) (24-34 es 
ne Se a Ty) pp) 
ge Cana, (62-95) 
‘50 Senge 
Fig. 366. Macrosiphum gaurae 
Alate Vivipara. Head and thorax pale brown; abdomen mottled pink or green; antenna 
dusky beyond base of III; cornicle and tibiae pale*or brownish with blackish tips; cauda and 
anal plate pale; tarsi black. Body length 2.2-3; hind tibia 1.85-2. Otherwise as in apterous 
vivipara except as figured. 
Ovipara. Apterous. Pale yellowish green or bright pink; appendages brownish yellow 
with tips of antennal IV and V and entire VI and tips of tibiae black; cornicle pale with 
blackish tip; cauda pale; hind tibia brown, slightly swollen on proximal half to two-thirds 
which portion bears numerous sensoria. Body length 2-2.5; hind tibia 1.2-1.5; antenna 2-2.5; 
cornicle .40; cauda .20 on median line, .25 on side. 
Male. Alate. Color in uncleared specimens mounted in balsam appears same as in alate 
vivipara. Body length 1.80; across eyes .48; hind tibia 1.55; antenna 2.55; cornicle .43, 
reticulated area .10; cauda .15 on median line, .20 on side, bearing 3-4 pairs of lateral hairs and 
usually a single dorsal preapicai one. 
Egg. Newly laid, pale yellowish to whitish; later, shining black. Size .80 by .35. 
Collections. On leaves of Gaura parviflora and Oenothera strigosa. 
Throughout region. Fundatrices April 28, apterous summer viviparae April 1 
to Sept. 29, alate viviparae May 22 to Nov. 3, sexuales Oct. 10 to Nov. 3; com- 
mon. 
Chief Distinguishing Characters. Green or pink body, cornicle length (less 
than antennal III), occasional presence of hairs on cornicle, length of reticu- 
lated area on cornicle (.12-.15), number of lateral hairs on cauda (about 4 pairs), 
number of sensoria on III (3-7 in apterous, 15-22 in alate vivipara) and rather 
long hairs on hind tibia (.05-.08) in apterous summer vivipara. 
