SUBFAMILY APHINAE 301 
This species is very close to M. solanifolii (Ashmead); differing only as 
follows: Longer antennal III, IV and V, III about 1 or longer instead of 
.70-.90, base of VI about twice as long as rostral IV-++V, instead of 1-1.3 times 
and cornicle usually longer (1.1-1.3). 
This species seems to differ from M. corallorhizae only in the longer anten- 
nal IV (not shorter than .74 instead of .70-.75). It appears doubtful that these 
species are distinct but without biological evidence of host plant transfers it 
seems best to leave them separate. 
Not figured on account of structural similarity to M. solanifolii. 
Macrosiphum crenicornum Smith and Knowlton 
Macrosiphum crenicornum Smith and Knowlton, 1939 :243. 
Apterous Summer Vivipara. “Light green with dark, faint longitudinal stripe on the 
dorsum.” (Mounted on slide), abdomen without dark areas at bases of hairs; head somewhat 
dusky; antenna, rostral IV+V, tarsi and tips of tibiae more or less dusky; cauda, cornicle 
and tibiae pale to slightly dusky. Body length 3-4 (‘3.45-5.07”’) ; across eyes .58-.62; antenna 
3-3.25 (‘*3.4-3.8’’); hind tibia 2-2.4, (“'2.33-2.77”); rostrum attaining 3d coxa. Cornicle imbri- 
cated, without reticulation, bearing about 11 hairs. Cauda slightly tapering, blunt, bearing 
about 8-10 hairs on each side and about 3 dorsal ones. 
Alate Vivipara. Color same as apterous vivipara. Body length 2.25-2.5 (‘‘2.82-2.92’’) ; 
across eyes .58-.62; antenna 3-3.3 (‘3.17-4”); hind tibia 2.1-2.4; rostrum attaining between 
2d and 3d coxae. Hind tibia with proximal third occasionally bearing about 6 sensoria, partly 
clustered and partly scattered. 
Apt. © 
ParatypesS.76 sen, 3-29-14 65%. 
iN Roeaieedge =7,5 290 68-75. <8 Vig 
Apt. Fey at ae ee ee 
=Alate 
S 
o Pa) 
"18-28" 
Fig. 358. Macrosiphum crenicornum 
Ovipara. Apterous. Same as apterous vivipara except proximal half of hind tibia swollen 
and bearing numerous sensoria. 
Male. Alate. Similar to alate vivipara except slightly smaller and antenna bearing 
numerous sensoria on III, IV and V as shown in figure. 
Collections. On Geranium richardscni and G. sp. Utah: Aspen Grove, 
Card and Logan Canyons, Monte Cristo, Mounts Nebo and Timpanogos, Sardine 
Canyon and along Beaver Creek, alcng the latter als» in Idaho. Apterous vivi- 
parae June 16 to Sept. 13, alate viviparae July 18 till in August, sexuales July 18 
and in August; not common. 
Type. U.S.N.M. Paratypes, C. F. Smith and Knowlton Collections. 
Chief Distinguishing Characters. Absence of reticulation on _ cornicle, 
length of unguis (.7-1.1 times III, 8-1.14 times IV), immaculate, light green 
body, length of cauda (.35-.45) and bearing 8-10 pairs of hairs, length of rostrum 
IV+V (.18-.21, 1.5 times hind tarsus), length of cornicle (.53-.90) and presence 
of about 11 hairs on cornicle and numerous hairs on cauda and rostral IV+V. 
