72 APHIDS OF THE ROCKY MOUNTAIN REGION 
a as Myzocallis coryli (Goeze) 
Vertex 
of Alate VIV. 
Vertex Je 
of Alatotd Nymp 
Fig. 72. Myzocallis coryli 
Aphis coryli Goeze, 1778:311. 
Myzocallis coryli, Davis, 1910d:417; Theobald, 1927 :332. 
Alate Vivipara. Pale yellowish green or white throughout, including legs (except tarsi 
and tips of tibiae) and rostrum (except tip); wings hyaline. Body length 1-1.5; hind tibia 
.8-1; antenna 1.3-1.7. Hairs pointed, sparse; on vertex and body .02-.03 long; on antennal III 
and hind tibia .01-.02. Cauda knobbed; anal plate bilobed. Fore wing with radial sector faint, 
media twice-forked. 
Ovipara. Apterous. Body 1.5 by .7; hind tibia .5, proximal two-thirds swollen and bear- 
ing many sensoria; antenna imbricated, .82-1 long; rostrum attaining 2d coxa. Hairs capitate; 
.07-.15 long on body; on appendages pointed, .03-.05 long. 
Male. Alate. Similar to alate vivipara. Antenna bearing sensoria on III, IV, V and VI. 
Collections. On Corylus sp. and Alnus sp., on leaves. Colorado: Fort Col- 
lins. Utah: Providence (in a nursery) and Logan. Alate viviparae June 22 and 
Sept. 24; rare. 
Myzocallis discolor (Monell) 
The Eastern Dusky-winged Oak Aphid 
anrened 
SSI 
30-40 24-34 Say 
Sy casNANN = ssenercenewervinsaronereetees 
da. 
M014 Yr .20-32 ie 
Hd ars 
Ta~™ 03 
Fig. 73. Myzocallis discolor 
Callipterus discolor Monell, 1879:30. 
Myzocallis discolor, Baker, 1917a:420; Gillette and Palmer, 1931:889. 
Alate Vivipara. Head and thorax dark; abdomen greenish or yellowish, spotted on dor- 
sum with dusky to blackish; venter blackish especially on III to VII; cornicle and area sur- 
rounding base dusky; antenna annulated; tibiae except tips, cauda and anal plate pale. Fore 
wing with conspicuous dusky bands, radial cell clear, radial sector very slightly fainter than 
other veins; media twice-forked. Body length 1.5-2; hind tibia .9-1; antenna 1.80; rostrum 
attaining between Ist and 2d coxae. 
Collections. On leaves of Quercus sp. Colorado: Colorado Springs. Alate 
viviparae June 22; apparently rare. 
