The Aghididae of Nebraska 41 



and cubitus originating equidistant and continuing very nearly parallel to 

 the margin of the wing. Stigmal vein curved rather sharply and evenly 

 its entire length. Second branch of cubitus originating, generally, equi- 

 distant from the first branch and the apex of the wing. Legs with the 

 basal portion of femora yellowish, all the rest black. While the insects 

 are living the abdomen appears as if without any darker markings, but 

 when mounted in balsam a row of brown spots can be seen on each 

 margin, and within these a row of impressed dots; apical segment drawn 

 out into a blackish point, causing the insect to appear as if supplied with 

 two tails. Honey tubes black, very finely annulated, 0.50 to 0.60 long. Tail 

 short (0.15 mm.), very acute, blackish. The whole insect in all forms is 

 covered with numerous short, bristly hairs which are most abundant on 

 the legs and antennae. Length of body about 3 mm., to tip of wings about 

 5.15 mm. 



On stems, branches and leaves of thistle (Cnicus sp.), in very- 

 large colonies. War Bonnet Canyon, June 23, 1890. 



This is the largest aphis that I have ever seen. It is somewhat 

 like A. carditi Linn., but is much larger, differently colored and 

 differs in many other respects as will be seen by the description. 

 I do not think that it can possibly be that species, especially as 

 given by Buckton. There is another aphis found on the same 

 plant, which I take to be A. carditi, though it differs in a few 

 points from that species, as given by European authors. Buck- 

 ton thinks that his insect is different from A. cardui of Passerini 

 and it is possible that my insect may be Passerini's species ; but 

 as I have no description of his insect I cannot determine that 

 point. I think it probable, however, that they are distinct. Oest- 

 lund notices the long beak of his A. cardui and the same feature 

 is to be noticed in this insect and in an undetermined species feed- 

 ing on the same plants. When we remember that these plants 

 generally have thick skins supplied with many long hairs, the 

 necessity of a long beak is at once recognized. 



Cotypes in collection of the University of Nebraska (no. 57) 

 and of the U. S. National Museum (no. 64). 



48. Aphis cucumeris Forbes. 



Ashland, August, 1890, on cucumber and hollyhock, specimens 

 nos. 58 and 59, collection of the University of Nebraska. 



T25 



