SANBORN : KANSAS APHIDIDiE. 55 



verulency is removed the aphis is of a greener appearance ; also 

 a marginal row of black spots, of which there are four on each 

 side, are more distinct. Extending across the abdomen are 

 about seven or eight dark transverse bars. The honey-tubes 

 are dark, incrassate, and 0.10 mm. long, not extending to the 

 base of the style. The style is dark, hirsute, acute, and 0.12 

 mm. long by 0.12 mm. wide at the base. Total length of the 

 body, 1.90 mm. 



This species was taken from hotbed cabbage, April 23. Later 

 in the season it was found on a great many other plants of the 

 same genus. It is gregarious, and colonizes both sides of the 

 leaves and the tenderest parts of the remainder of the plant. 



Aphis cardui Linn. Plate XVI, fig. 83. 



Head brownish black. Antenna^ black ; length of segments : 

 I, Oram; II, mm; III, 0.56mm.; IV, 0.38 mm. ; V, 0.23 mm. ; 

 VI, 0.12 mm.; VII, 0.48 mm. About twenty-four circular 

 sensoria on the third joint. Eyes dark, tinged with red. Beak, 

 0.97 mm. long, extending to the caudal boundaries of the 

 mesocoxse. 



Prothorax short, brownish yellow, with a cephalic black bor- 

 der. Thoracic sclerites mostly black, with membrane brownish 

 yellow. Wings hyaline, veins frail ; stigma, 0.64 mm. long 

 and 0.16 mm. broad; total wing expansion, 6.48 mm. Legs: 

 Distal half of femora dark brown, becoming paler near the 

 proximal end ; tibia dark brown at the distal end and paler 

 proximally ; tarsus dark brown. 



Abdomen varies in color with the age. Normally there is a 

 dark quadrate patch on the dorsum in the region of the honey- 

 tubes. There are also about three dark patches on the lateral 

 margins of the abdomen ; the segments caudad of the honey- 

 tubes have transverse black bands. Honey-tubes black, clavate, 

 and 0.34 mm. long. Style has distal half and lateral borders 

 black, remainder brownish yellow ; total length ,0.14 mm. , being 

 as broad at the base as it is long. Total length of body, 

 2.22 mm. 



This form was taken June 8. It is gregarious on the com- 

 mon thistle (Cardns ItDtceolatus) . The colony shows a varie- 

 gated appearance in color. The young are quite green and the 

 old are nearly black. 



