No. 34-] HEMIPTERA OF CONNECTICUT: APHIDIDAE. 313 



5. Number of annulations on joint v of antennae equal to or greater 



than that on iv, rarely less lanigerum 



(Fundatrigenia) 

 Number of annulations on joint v of antennae equal to or less than 



that on iv, rarely more : pyricola 



(Fundatrigenia) 



6. Distance from tip of fore wing to fork of M and base of stigmal 



vein subequal 7 



Distance from tip of fore wing to fork of M less than that to base 



of stigmal vein rileyii 



(Fundatrigenia) 



7. Joint iv of antennae with from six to nine annulations. V with 



from five to nine crataegi 



(Sexuparae) 

 Joint iv of antennae with three to five annulations, v with four to 



six lanigerum 



(Sexuparae) 



E. americanum (Riley). Schizoneura americana Riley (in part 

 of Riley and subsequent authors). 



Bull. U. S. Geol. Geog. Surv. Terr., v, 4, 1879. 



This common species causes a leaf roll on American elm similar 

 to that on English elm due to ulmi. It has been confused in litera- 

 ture with the elm generations of both ulmi and lanigerum. It 

 migrates to Amelanchier, the roots of which are inhabited by the 

 summer generations. For life history account see Patch (1915a). 



On elm, Madison, July .3, 1912 (P. S. Piatt) ; Norfolk, 28 June, 1914 

 (Edward Quintard). 



E. crataegi (Oestlund). Schizoneura crataegi Oestlund. 



Aphid, Minn., 27, 1887. 

 E. lanigerum (Hausmann). Aphis lanigera Hausmann. Erio- 

 soma americana (in part of Riley and of subsequent authors). 

 (PL viii, 3.) 



111. Mag. Ins., i, 440, 1802. 



This, like the other American species of this genus, has the elm 

 for its primary host plant. The stem female hatching from the 

 overwintering egg on the elm starts the leaf deformation known 

 as rosette or leaf cluster of Ulmus americana which is inhabited 

 by her progeny. The spring migrants fly to the ventral surface 

 of the leaves of Pyrus and Crataegus and their nymphs seek the 

 bark of these trees (on trunk and on root). This species also has 

 hibernating nymphs which persist through the winter on its 

 secondary host plant, but the egg stage is normally passed only on 

 Ulmus. For literature on this species see Baker (1915), Maxson 

 (1915), and Patch (1916b). 



On elm, New Haven, 4 June, 1904 (B. H. W.) ; on Crataegus, New 

 Canaan, 15 Sept., 1905 (W. E. B.) ; on apple, Southington, 18 Apr., 1903; 

 New London, 18 Sept., 1906; Fairfield, 26 Oct., 1908; New Britain, 10 

 June, 1910; Orange, 22 June, 1910; Groton, 29 June, 1910; New Haven, 

 1 July, 1910; Groton, 2 July, 1910; Seymour, 4 Oct., 1911; Putnam, 24 

 Oct., 191 1 ; Clinton, 26 Oct., 191 1; West Haven, 11 Dec, 191 1; Riverside, 

 16 July, 1912; Sharon, 28 Oct., 1912; New London, 15 Apr., 1913; Milford, 



