36 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Chaitophorus populicola Fitch. Plate VII, fig. 42. 



Head black. Aiitennoe black and very hirsute ; length of 

 segments: 1,0.01 mm.; II, 0.09 mm.; Ill, 0.45 mm.; IV, 

 0.27 mm.; V, 0.19 mm.; VI, 0.09 mm.; VII, 0.21 mm.; to- 

 tal length, 1.37 mm., extending nearly to the central part of 

 abdomen. Sensoria circular ; about forty on the third segment, 

 about twenty on the fourth, fifteen on the fifth, and a large one 

 closely connected with about five small ones at the distal end of 

 the sixth. Eyes black ; ocular tubercles present but not con- 

 spicuous. Beak dark, extending to the mesocoxtp, being 0.63 

 mm. long. 



Prothorax and thorax black. Wings smoky, veins black, 

 robust. Stigma dark, 0.63 mm. long by 0.18 mm. broad. 

 Total wing expansion, 5.76 mm. Legs of good size, black and 

 hairy. 



Abdomen greenish black, nearly always marked with black 

 transverse bars, also with a marginal row of black patches. 

 Honey-tubes greenish black, 0.09 mm. long, nearly one-half the 

 tarsi in length. Style almost obsolete, hirsute, distal half black, 

 about 0.07 mm. in length, or nearly as long as the honey-tubes. 

 Body all hirsute, and 2.54 mm. long. 



This form was taken on the leaves of the cotton wood {Populus 

 monilifera) , October 12. Being gregarious in habit, it colonizes 

 both sides of the leaves. The colonies, which live through the 

 summer, are closely guarded by ants, which protect them from 

 their insect enemies. It was a large black species of ant which 

 protected the forms taken and described. About one ant would 

 have charge of a single leaf, and would fight until killed or 

 thrown away from his flock. This aphid was common here 

 during the summer months. 



Chaitophorus stevensis, n. sp. Plate VII, fig. 47. 



Head black. Antennne dark, distal half black, all hirsute ; 

 length of segments: I, 0.128 mm.; II, 0.07 mm.; Ill, 0.41 

 mm.; IV, 0.3 mm.; V, 0.25 mm.; VI, 0.09 mm.; VII, 0.1 

 mm. ; total length, 1.17 mm., extending to near the center of 

 the abdomen. Sensoria circular ; fifteen to twenty on the third 

 segment, none on the fourth, the usual one near the distal end 

 of tiie fifth, and a cluster of ten or twelve at the distal end of 

 the sixth. Eyes black, ocular tubercles prominent and tinged 



