HEMIPTERA OF COLORADO 
117 
ooxae. Antennae smooth. No fully developed individuals were obtained, so that the 
aetermation is somewhat Questionable.” 
Hotchkiss, Delta County, August 19th, in wooly patches 
on young shoots of Quercus undulata (Cowen). 
Z,achnus pini L. 
‘‘Length 3.15 mm., width 1.80 nun. Legs and antennae slightly pubescent with short 
ne airs. Body scarcely at all pubescent. Rostrum extending beyond middle of 
abdomen. Lengths of antennal joints: III, 0.60 mm.; IV, 0.20 mm.; V, 0.25 mm.; VI, 0.15 
Estes Park, July 15th on twigs of Pinus ponderosa var. 
scopulorum (Gillette). These specimens differ from the 
description given by C. M. Weed (Art. V. Aphididae, p 118) 
in the characters given above (Cowen). 
Melanoxanthus bicolor Oestl. 
Fort Collins, September 30th on Salix (Baker). 
Melanoxanthus salicis L. 
Fort Collins, October 8th on Populus balsamifera var. 
candicans (Baker). 
Chaitophorus negundinis Thos. 
Fort Collins, common on Negundo aceroides throughout 
the season (Cowen). 
Chaitophorus nigrae Oestl. 
Fort Collins, June 21st on Salix longifolia (Cowen). 
Chaitophorus populicola Thos. 
Fort Collins, July 5th, on Populus monilifera (Gillette). 
Foit Collins, June 24th, on young shoots on Populus 
angustifolia (Cowen). 
Drepanosiphum acerifolii Thom. 
Fort Collins, July 2d on under side of leaves of Acer 
dasycarpum. Flies quickly when disturbed in the warmer 
part of the day (Cowen). 
Aphis albipes Oestl. 
Fort Collins, July P2th, on underside of curled leaves of 
Symphoricarpos occidentalis (Cowen). 
Aphis arnioraciae Cowen n. sp. 
‘‘Apterous viviparous female: Length of body 1.90 mm. Length of antennae about 
1.10 mm. Antennae, head, extremity of beak, femora, tarsi, and honey tubes, deep dusky 
