The Aphididae of Nebraska 27 



Honey tubes conspicuous, brown. Tail short, brown margined. Abdomen 

 with rather broad, brownish tip. Front pair of legs all yellowish ; second 

 and third pairs with dusky femora and yellowish tibiae. All with dusky 

 tarsi. Length of body about 1.90 mm., to tip of wings 2.75 mm. 



Very close to Chaitophorus populi (Linn.) and C. popiilifoliae 

 (Fitch), but differing in coloration, size, markings and color of 

 honey tubes, as well as feeding on a different plant. 



On leaves and young branches of Sali.v cordata, Squaw Canyon, 

 June 24, 1890. 



Type in the collection of the U. S. National Museum (no. 39). 



26. Chaitophorus nigrae Oestlund. 

 Oestlund, List Aph. Minn., p. 49 (1886). 

 Oestlund, Syn. Aph. Minn., p. 40 (1887). 



Apterous form: General color dull blackish brown. Body flat, ovate, 

 covered with long white hairs, dorsum more or less tuberculate, especially 

 when the lice are young. Antennae rather more than half as long as the 

 body, with pale base and growing darker towards the tip, hairy. More or 

 less yellowish along the sides of the abdomen. 



Winged form: Head and thorax black. Antennae almost as long as 

 body, hairy, black, with base of III paler ; III longest. Beak hardly reach- 

 ing middle coxae. Wings with slender blackish brown veins ; stigma short 

 and broad, dusky brown. Legs with distal half of femora and tarsi black- 

 ish, rest pale. Abdomen very dark green to black. Honey tubes about as 

 long as broad, paler than abdomen. Tail short, knobbed. Length of body 

 1.50 mm., to tip of wings 2.50 mm. 



Found on leaves and young shoots of willow (Salix nigra and 

 5\ longifolia). Lincoln, October, 1888. A further study of this 

 species will probably result in showing that it is but a variety of 

 C. viminalis Monell. 



Specimens in collection of the University of Nebraska (no. 

 26) and of the U. S. National Museum (no. 41). 



27. Chaitophorus populicola Thomas. 



On Populus monilif era, Lincoln, July 11, 1890, specimens in the 

 collection of the University of Nebraska (nos. 27-32). 



28. Chaitophorus salicti (Schrank). 



Schrank, Fn. Boi., II, p. 103 (1801). Aphis salicti. 

 Kaltenbach, Mon. Pflan., p. 121 (1843). Aphis salicti. 

 Passerini, Gli afidi, p. 32 (i860). Chaitophorus salicti. 

 Apterous viviparous female: Long oval. Color yellowish green, with 



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