I 



Williams' "The Aphididae of Nebraska" 19 



0.061 0.061 0.51 0.16 0.104 0.38 mm 



Length of body, 1.6 mm; width, 0.7 mm; length of cornicles, 0.27 mm; 

 style 0.14 mm. Wing venation as in camera lucida drawing. 



Camera lucida drawings of the head, antenna, wing, cornicle 

 and style given on Plate IV, figs. 6y to 70. 



69. A. sativae Williams. 



" Aphis sativae n. sp. Type No. 87. On Cannabis sativa, 

 Weeping Water, Oct. 10, 1888." 



This slide bears two wingless, both apparently immature, and 

 one winged. The winged individual is badly mutilated and is in- 

 determinable. The antennae and wings are gone and the body 

 which remains is an unrecognizable mass. 



70. A. senecionis Williams. 



" Aphis senecionis n. sp. No. 88. On Senecio canus. War 

 Bonnet C, 6/30, '90." 



Two winged and several adult wingless on the slide. 



Winged viviparous female: Antennal segment III with 22 to 25 irregu- 

 larly placed sensoria which vary more or less in size; IV with 7 to 9 sen- 

 soria more or less in a row; and V with i to 4, not including the usual 

 distal one. Measurements of two of the antennae as follows : 



The lateral thoracic tubercles prominent. Wing veins slender and pale 

 brownish; vein Mi (first branch of the third discoidal) branching at a dis- 

 tance nearer the tip of the wing than to where il/a+t branches. Length of 

 body, 1.37 mm; width, 0.58 mm; length of cornicle, 0.15 mm; of style, 0.13 

 mm; of hind tarsus, 0.13 mm. 



Camera lucida drawings of the antenna, wing, cornicle and 

 style shown in Plate IV, figs. 71 to 74. 



271 



