34 KANSAS UNIVERSITY SCIENCE BULLETIN. 



Genus Drepanosiphum Koch. 



Antenna^ longer than the body and fixed on frontal tubercles ; 

 setaceous seventh joint as long or longer than the third, latter 

 with a single row of rather large sensoria. Eyes bright red. 

 Beak short ; penultimate joint long in proportion. Wings long 

 and narrow ; marginal cell elongated towards the apex of the 

 wing. Discoidals nearly parallel to each other. Honey-tubes 

 moderately long, enlarged near the base. Style inconspicuous 

 or none. 



Chaitophorus. Plate VII, fig. 43. 



Head black. Antenn^ie hirsute, dark, darkest on the distal 

 half; length of segments : I, 0.05 mm. ; II, 0.03 mm.; 111,0.16 

 mm. ; IV, 0.12 mm. ; V. 0.1 mm. ; VI, 0.07 mm. ; VII, 0.25 

 mm. ; total length about 0.80 mm., extending a little beyond the 

 thorax. Sensoria circular and not equal in size. There are 

 about twelve on the third joint, sometimes one on the fourth, 

 two on the fifth, and eight small and one large one on the distal 

 end of the sixth. Eyes red, ocular tubercles prominent, and 

 ocelli normal. Beak pale yellow, 0.23 mm. long, its extent 

 being midway between the pro- and mesocoxa\ 



Prothorax black, its lateral tubercles not very conspicuous. 

 Thorax black ; wings pellucid, veins light brown. Stigma dark 

 brown, 0.14 mm, broad and 0.54 long. Total wing expansion, 

 4.35 mm. Legs dark, hirsute with longer hairs tha!i are -hown 

 in the illustration. 



Abdomen and the rest of the body armed with long hairs 

 which are mounted on small pale yellow tubercles. Terga 

 colored with transverse black bands which frequently become 

 confluent on the median line. Black spots laterad of these are 

 on each margin of the terga. Honey-tubes black, imbricated, 

 and about as long as broad. Style black, armed with long 

 hairs. It is distinctly knobbed and equal to the honey-tubes in 

 length, being 0.50 mm. Total length of the body, 1.37 mm. 



This form was taken May 25, on the willow (Salix glauco- 

 j)hyUa). It is gregarious in habit and colonizes the leaves. 

 These apliids were apparently exterminated here three times 

 last year, by the ladybird beetles, in a certain willow grove 

 which was nearly submerged by water for a period of nearly a 

 week. The gradual rise of water drowned or drove the aphids 

 to the tops of the trees. Here they fell an easy prey to the 



