June, ’18] 
GILLETTE AND BRAGG: APHIS BAKERI, ETC. 
333 
Alate Males. Examples taken along with the sexupara described above. Color 
of abdomen apparently lighter than in the alate viviparous forms; length, 1.40 mm.; 
antenna (figure 24) as long as the body, filament about as long as joints V and VI 
combined; sensoria on joint III, about 50; joint IV, about 35; joint V, about 25; and 
joint VI with permanent sensoria only; cornicles shorter than hind tarsi; hind tibiae 
70 mm. in length, not swollen at base and entirely without sensoria. The male is 
very readily separated from the other alate forms, but the spring and fall migrants 
resemble one another rather closely. 
Oviparous Female. What appear to be mature apterous egg-layers in alcohol 
may be described as follows: color almost uniform pale yellow throughout, length 
1.25; antennae .58; and hind tibia .52 mm.; antenna with permanent sensoria only; 
hind tibia swollen and set with abundant sensoria throughout its entire length; cauda 
very broadly rounded posteriorly and broader than long. Examples taken along 
with the sexupara and males described above from Amelanchier. See figures 25 and 
26. 
This is an interesting species from a morphological standpoint, and 
it is very closely allied to viburnicola. 
Aphis bakeri Cowen (Fig. 13, 1-8) 
Aphis bakeri Cowen, Hemiptera of Colorado, Bull. 31, Colorado Experiment Station, 
p. 118, 1895. 
Aphis cephalicola Cowen, Hemiptera of Colorado, Bull. 31, Colorado Experiment 
Station, p. 118, 1895. 
Aphis bakeri, Gillette, Journal of Economic Entomology, 1910, p. 405. 
Aphis bakeri, Gillette and Taylor, Bull. 133, Colorado Experiment Station, p. 28, 
1908. 
We find this species living throughout the year on clover and giving 
migrants to apple and Cratcegus in the fall. On occasional years it 
becomes quite injurious to red clover. This was specially true in 
northeastern Colorado and parts of Idaho and Utah in 1916, crops 
being almost ruined in some cases. 
Aphis crataegifoliae Fitch (Fig. 13, 9-13) 
Aphis cratcegifolice Fitch, Cat. Horn. N. Y. St. Cab., p. 66, 1851. 
Aphis cratcegifoli Thomas, 8th Rep., Insects of Illinois, p. 101, 1879. 
Aphis cratcegifolice Oestlund, Aphididse of Minn., p. 51, 1887. 
Aphis brevis, Sanderson, 13th Annual Rep., Del. Exp. Sta., p. 157, 1902. 
Aphis brevis. Patch, Jour. Agr. Res., vol. Ill, p. 431, 1915. 
Aphis cratcegifolice , Quaintance and Baker, Farmers’ Bull. 804, p. 18, 1917. 
We have not taken this species in Colorado, but have specimens 
from other states as follows: 
Knoxville, Illinois, September 12, 1907, from Red Haw, J. J. Davis. 
Orono, Maine, June 14, 1912, from Cratcegus , Edith M. Patch. 
Winthrop, Maine, October 8, 1913, from Cratcegus, A. C. Baker. 
Aphis bakeri occurs freely upon Cratcegus in Colorado, but is dis¬ 
tinguished by its short beak. 
