The Aphididae of Nebraska 9 



second discoidal. Terminal space between the first and second discoidals 

 and between the last and cubital subequal ; that between cubital and stigmal 

 only half as great. Discoidals of hind wings proceeding connectedly 

 from subcostal. Promiscus reaching beyond front coxae ; abdomen with 

 7 rather large round spots on each side, each sending out 2 hairs. (In 

 some specimens the cubital starts independently from the subcostal; in 

 others it joins the second discoidal a short distance from the base.) Pupa 

 with third joint of antennae relatively somewhat shorter. 



Larva of probable second generation: Antennae smooth, 4-jointed; III 

 longer than IV and as long as I and II together; apical nipple one sixth 

 as long as IV. Promiscus slender, reaching beyond hind coxae. Legs 

 rather long and stout. Tibiae, tarsi and anal joints of abdomen with a 

 few conspicuous hairs. Full grown apterous female, probably of same 

 generation, differs in having 6-jointed antennae, proportioned much as in 

 the winged female. 



Larva from zvinged female (probably fourth generation) : Antennae 

 5-jointed; I, II, III and IV subequal in length; III and IV stouter; V very 

 short and rounded at tip. Promiscus very long, reaching beyond tip of 

 abdomen. 



Infesting the terminal leaves of ash (Fraxinus americana and 



5. sambucifolia) from spring till late summer, and producing a 

 twisted curl thereof ; the young lice varying in color from deep 

 glaucous to livid, very flocculent and exuding the liquid globules 

 quite copiously; winged females appearing early in June (Riley). 



On ash {Fraxinus americana). Ashland, May 25,1890. Lin- 

 coln, June 4, 1890, when the first winged females were found. 



Specimens in collection of the University of Nebraska (nos. 6, 

 7) and of the U. S. National Museum (nos. 122, 123, 339). 



6. Pemphigus populicaulis Fitch. 



Fitch, Ins. N. Y., V, p. 845, par. 353 (1859). 



Walsh, Proc. Ent. Soc. Phil., I, p. 305 (1862). Byrsocrypta (pemphi- 

 gus) populicaulis. 

 Thomas, Ins. 111., 8th Rep., p. 149 (1S79). Pemphigus populicaulis. 

 LeBaron, Ins. 111., 3d Rep., p. 193 (1873). 

 Oestlund, Syn. Aph. Minn., p. 21 (1887). 

 Stem-mother: Subglobose, pale yellowish. Antennae 4-jointed, brown- 

 ish. Legs and coxae brown. Beak short, pale, brown tipped. Eyes im- 

 perfect, blackish. 



Pupa pale yellowish. Eyes red. Legs, antennae and wing-pads whitish. 

 Antennae 6-jointed, III longest. 



Winged viviparous female: Head and thorax black. Eyes dark red. 



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