30 Thomas Albert Williams 



Winged individuals: Head and thorax black; abdomen black, except the 

 margins and tail, which are yellow. Honey tubes a little longer than 

 thick, yellowish, often slightly fuscous. Antennae hairy; VII filiform, 

 almost as long as the three preceding taken together. Wings hyaline. 

 Length of body 1.52 mm., to tip of wing 2.54 mm. (Monell). 



Apterous form on leaves of heart-leaved willow (Salix cor- 

 data). Weeping Water, August 18, 1890. Monell says the vena- 

 tion of the wings is exceedingly variable. 



Specimens in collection of the University of Nebraska (no. 36) 

 and of the U. S. National Museum (no. 50). 



Genus Callipterus 

 31. Callipterus asclepiadis Monell. 



Monell, Bull. U. S. Geol. Sur. Ten, Vol. I, p. 29 (1879). 

 Thomas, Ins. 111., 8th Rep., p. 197 (1879). 

 Oestlund, Syn. Aph. Minn., p. 42 (1887). 



Apterous individuals: Uniformly yellowish or whitish; somewhat tuber- 

 culate on dorsum, with long white capitate hairs. Antennae shorter than 

 body, all but two first joints black tipped, VII longer than VI. 



Pupa: Similar to apterous form, with pale wing-pads, antennae gener- 

 ally shorter and body longer. 



Winged individuals : General color yellow. Antennae filiform, about the 

 length of the body, VII nearly twice as long as VI, all but two basal joints 

 black tipped. Beak reaching to second pair of coxae. Thorax with a 

 dark marginal stripe on the sides. Legs pale. Wings with a dusky brown, 

 irregular band running from the apex of the second discoidal to the apex 

 of the second branch of the cubitus and to apex of stigmal vein, and 

 another band extending from the apex of the first discoidal to the base of 

 the cubitus, but becoming scattered before reaching that point. Veins 

 blackish. Stigma short, broad, angled, tapering abruptly at its outer end. 

 Distance between the tips of first and second discoidals twice that between 

 the tip of the second discoidal and the tip of the first branch of cubital. 

 Hind wings with veins only very slightly smoky at the tips. Abdomen 

 with four irregular rows of brown spots and smaller spots scattered among 

 these. Honey tubes short, slightly longer than broad, yellow. Length of 

 body 1.50 to 1.60 mm., to tip of wings about 2.80 mm. 



On under side of leaves of milkweed {Asclepias syriaca), gen- 

 erally only a few are to be found on a leaf. Weeping Water, 

 September 8, 1889; Ashland, August 25, 1890. I find the vena- 

 tion rather variable. This species has the habit of jumping when 

 disturbed. It is able to jump several inches. 



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