The Aphididae of Nebraska 29 



cles. These hairs are most numerous along the middle of the abdomen, 

 where they are arranged in two irregular broad rows, one each side of 

 the median line. Front very spiny. Antennae about half the length of 

 the body; tips of II-V and all of VI and VII black, rest pale; VII but 

 little longer than VI ; with few scattered hairs. Eyes red. Legs short, 

 rather stout, yellowish with dusky tarsi. Homey tubes yellow, with a large 

 thickened rim at the tip, 0.17 mm. long. 



Winged viviparous female: General color yellowish green. The black 

 hairs of the apterous form are wanting. Head brown. Thorax black. 

 Antennae rather more than half the body in length; III as long as IV 

 and V together, VI longer than VII ; colored as ini the apterous female. 

 Eyes red. Wings rather large, with a broad blackish brown stigma and 

 robust costal and subcostal. All the veins of both front and hind wings 

 with broad smoky black bands. Second discoidal of front wing very 

 sharply curved toward the body near its apex. Front pair of legs yellow- 

 ish, with dusky joints and tarsi; middle pair darker, only base of femora 

 and middle portion of tibiae yellow ; hind pair nearly all black. Abdomen 

 with a longitudinal row of tubercles each side of the median line, each 

 segment bearing two tubercles, one each side of the line. Honey tubes 

 as in apterous female but rather longer. Tail short and knobbed, hairy, 

 concolorous with abdomen. Length of body 2.60 mm., to tip of wings 

 4.40 mm. 



On the under side of leaves, along the midrib and larger veins 

 of Bur oak (Quercus macrocarpa). Very plentiful during the 

 seasons of 1889 and 1890 at Ashland. The winged form was 

 first found May 14, 1890, and by the twenty-fifth they were very 

 numerous. The apterous oviparous females were found plenti- 

 fully in September and October. They do not differ from the 

 other apterous form except in shape and in having the abdomen 

 drawn out posteriorly as is common in this genus. All of the 

 forms of this species have less hair on the antennae than any 

 other species known to me. The antennae are more like Callip- 

 terus, but all the other characters are those of Chaitophorus. 



Specimens in collection of the University of Nebraska (no. 35) 

 and of the U. S. National Museum (no. 49). 



30. Chaitophorus viminalis Monell. 



Monell, Bull. U. S. Geol. Sur. Ter., Vol. V, No. 1, p. 31 (1879). 

 Thomas, Ins. 111., 8th Rep., p. 200 (1879). 

 Apterous individuals: Varying from pale green to light yellow, with 

 two darker vittae on the abdomen which are often obsolete. Entire insect 

 covered with long white hairs. 



113 



