The Aphididae of Nebraska 43 



and stigma. Abdomen yellowish green, with generally three longitudinal 

 dark green stripes as in apterous. Honey tubes blackish, about twice the 

 length of the yellowish tail. Anal plates brown. 



Along the midrib on the under side of leaves of buckthorn 

 (Rhamnus lanceolatus) . July, Fremont, Wabash. When mounted 

 in balsam the dark green stripes disappear and a row of impressed 

 dots can be seen along the carinae. One of the smallest aphids 

 that I am acquainted with. 



Specimens in collection of the University of Nebraska (no. 62) 

 and of the U. S. National Museum (no. 66). 



51. Aphis helianthi Monell. 



Monell, Bull. U. S. Geol. Sur. Ter., V, 1, p. 26 (1879). 



Oestlund, Syn. Aph. Minn., p. 52 (1887). 

 Apterous viviparous female: Pale to dark green, with various darker 

 markings, especially just before the honey tubes, where there is a trans- 

 verse band. Eyes blackish. Honey tubes dusky, 0.20 mm. long. Tail 

 short, acute, more or less dusky. 



Winged viviparous female: Head and thorax dark brown to black. Ab- 

 domen green, with a dark green transverse band just before the honey 

 tubes and generally some dark marginal spots. Antennae about two thirds 

 as long as the body, black; III as long as IV and V together and longer 

 than VII ; IV and V subequal. Eyes very dark brown to black. Honey 

 tubes dusky to black, 0.20 mm. long, subcylindrical. Tail as in apterous 

 form. Wings hyaline, with a broad, dusky stigma; second branch of 

 cubital arising much nearer the apex of wing than to base of first branch. 

 Length of body 1.80 mm., to tip of wings 3.20 mm. 



Very common on under side of leaves of sunflower (Helian- 

 thus animus), generally but not always corrugating them. June- 

 September. Ashland, Lincoln, Weeping Water. 



Specimens in collection of the Llniversity of Nebraska (nos. 63, 

 64) and of the U. S. National Museum (nos. 82, 83, 332). 



52. Aphis impatientis Thomas. 



On Impatiens pallida, August 22, 1890, specimens nos. 65 and 

 66, collection of the University of Nebraska. 



53. Aphis lilicola n. sp. 



Apterous viznparous female: Color varying from green to dark green 

 and variously mottled. Slightly pulverulent, more conspicuously so on the 

 head and margins of abdomen. Antennae very slender and thread-like. 



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