SANBORN : KANSAS APHIDID.E. 57 



the lateral tubercles. The latter are normal. Thorax black ; 

 wings nearly hyaline, veins dark brown and frail. Stigma, 0.09 

 mm. broad and 0.45 mm. long. Total wing expansion, 4.02 mm. 



Abdomen pale brown ; one lateral tubercle near the thorax ; 

 four black spots along the margin of the abdomen not shown in 

 the illustration. Apical segment also black. Honey-tubes 

 imbricated, nearly cylindrical, being a little wider at the base 

 than at the distal end; 0.18 mm. long, or twice the length of 

 the tarsi. Style black, hirsute, bluntly rounded at the lip ; 

 length, 0.10 mm., or a little more than half the length of the 

 honey-tubes. Total length of the body, 1.28 mm. 



This form was taken May 23, on the primrose {(Enothera 

 biennis). It is gregarious in habit and colonizes the terminal 

 growing parts of the plant. In Aphid. Minn., p. 62, 1887, 

 Oestlund names this species o iiothenr, but it seems to be identical 

 with gossypii Glov. 



Aphis vernonia Thomas Plate XXII, fig 100. 



Head black. Antennjie light gray, imbricated, and almost 

 naked ; length of segments : I, 0.03 mm. ; II, 0.05 mm. ; III, 

 0.16 mm. ; IV, 0.07 ram. ; V, 0.09 mm. ; VI, 0.09 mm. ; VII, 

 0.16 mm. ; total length, 0.70 mm., which extends a little beyond 

 the thorax, or about two-thirds the length of the body. Sensoria 

 circular, four to eight on the third joint, sometimes one near 

 the central part of the fourth joint, the usual one present near 

 the distal end of the fifth, and a cluster of about five which 

 border a larger one at the distal end of the sixth joint. Eyes 

 red ; ocular tubercles prominent ; ocelli normal and conspicuous. 

 Beak dark, 50 mm. long, extending to the central part of the 

 abdomen in some specimens, in others not quite as far, but most 

 always extending as far as do the antennip. 



Prothorax light brown, except the cephalic margin, which is 

 black ; lateraltubercles well developed and prominent. Thoracic 

 sclerites black, membrane lighter in color. Wings nearly hya- 

 line, veins dark. Stigma brownish black, 0.09 mm. broad and 

 0.45 mm. long. Total wing expansion, 3.70 mm. Legs nearly 

 uniform in color, being pale yellow ; tibia and tarsi a shade 

 lighter and slightly hirsute. 



Abdomen pale brown, with two tubercles caudad the honey- 

 tubes about the size of the lateral tubercles. Honey-tubes cylin- 



