50 Thomas Albert Williams 



Buckton, Mon. Brit. Aphid., II, p. 42, pi. XLIX, figs. 1, 2 (1879). 



Apterous viviparous female: Somewhat oval. Head brown between the 

 antennae, but sometimes the color is reddish. Rest of body yellow or pale 

 green. Legs rather short, pale green ; tarsi darker. Honey tubes straight 

 and cylindrical. Tail but little developed. The vertex and tail pilose. 

 Length of body about 1.50 mm., of honey tubes 0.38 mm. 



Winged viviparous female: Much smaller than the wingless female. 

 Head, part of prothorax and all of thorax rich brown. Vertex convex, 

 not pointed. Abdomen arched. Rest of insect fine yellow, with indistinct 

 lateral punctures. Antennae shorter than body, pale brownish yellow. 

 Legs, honey tubes and tail pale green. Tarsi grayish. Eyes red. Wings 

 short and rounded at the tips ; insertions and subcostal yellow ; veins 

 brown; stigma gray. Length of body about 1.25 mm., of honey tubes 0.25 

 mm., expanse of wings 4.81 mm. 



Apterous oviparous female: Very much of the form and color of the 

 viviparous female. Antennae half the length of body. Honey tubes olive 

 (Buckton). 



The apterous form of an aphis which agrees exactly with Buck- 

 ton's description was taken at Ashland November 1, 1890, on the 

 under side of the leaves of hollyhock {Althaea sp.). Winged 

 insects were taken later (January 23, 1891) on Hibiscus in green- 

 house at Lincoln. These agree very well with Buckton's descrip- 

 tion, but some specimens have black head and thorax, very small 

 lateral tubercles on the prothorax, a dark green spot at the base 

 of each honey tube and the honey tubes and tail black, thus agree- 

 ing with the description given by Koch. There is no doubt that 

 these belong to the same species and I think that the darker ones 

 are the more mature individuals. Apterous and viviparous fe- 

 males were taken often on Hibiscus later. 



Specimens in the collection of the University of Nebraska (nos. 

 74, 75) and of the U. S. National Museum (no. 100). 



60. Aphis medicaginis Koch. 



Koch, Die Pflan., p. 94 figs. 125, 126 (1854). 



Monell, Bull. U. S. Geol. Sur. Ter., V, No. 1, p. 24 (1879). 



Thomas, Ins. Ill, 8th Rep., p. 192 (1879). 

 Apterous viviparous female: Broadly ovate. The living specimens ap- 

 pear almost black, but when mounted in balsam they have a dark reddish 

 brown color. Legs and antennae pale yellowish, the base and tips of the 

 latter and the femoral tips of the hind pair of legs, all the tibial tips and 

 the tarsi dusky to black. Antennae not half as long as the body; III the 



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