The Aphididae of Nebraska 2 1 



of a tree at Lincoln, June, 1890, where it worked on both branches 

 and leaves. It causes a curling of the leaves similar to 3\ aincri- 

 cana, but the galls can be readily distinguished as those of this 

 species are much more tightly curled than are those of 5". Ameri- 

 cana. This latter species is often to be found on the same tree. 

 They can be easily separated, as they differ in size, antennae, 

 venation and other minor points. My specimens differ somewhat 

 from Dr. Riley's description, but I think that this is his species. 

 It was very plentiful on the elms of Lincoln the past season, and 

 could be seen in every crack in the bark of some trees. As they 

 are always covered with a coat of flocculent matter the trees are 

 rendered very unsightly. 



Specimens in collection of the University of Nebraska (no. 20) 

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



Genus Colopha 

 iS. Colopha ulmicola Fitch. 



Ashland, June 11, 1890, on Ulmus americana, specimens no. 

 20a and 20b, University of Nebraska collection. 



Subfamily LACHNINAE 



Genus Lachnus 

 19. Lachnus dentatus LeBaron. 



LeBaron, Ins. 111., 3d Rep., p. 138 (1872). 



Thomas, Ins. 111., 8th Rep., p. 116 (1879). 



Weed, Bull. O. Ag. Exp. Sta., Tech. Ser., Vol. I, No. 2, p. 117, pi. VII, 

 fig. 1 (a and b). 

 "Apterous viviparous female: Body broadly ovate, covered with a dense 

 fine pubescence. Color of body dark ashy gray, lighter posteriorly ; an- 

 tennae, legs (except basal two thirds of femora and ring at base of tibiae, 

 which are reddish brown), tubercular cornicles, tubercle on middle of 

 abdomen, beak and six transverse rows of six small circular spots on 

 dorsum of abdomen, the two middle spots being about half as large as 

 those at the sides, black. On the dorsum of the abdomen, slightly back of 

 the middle and coinciding with the position of the two middle dots of the 

 fourth row of spots is a prominent conical tubercle. Honey tubes reduced 

 to flattened tubercles. Head large, subquadrate. Beak reaching to first 

 abdominal segment. Antennae short, little more than twice as long as 

 the head ; III long. Length of body 5 mm. 



105 



