258 MAINE AGRICULTURAL KXPRRIMl^NT STATION. IQI2. 



1909. Schisaneura lanigcra. Gillette, C. P. Jotirnal Ec. Ent. Vol. 2, p. 

 356 and Fig. 15. "This is one of the most serious and generally 

 distributed insect pests of apple orchards in Colorado. 



1909. Schisoneura ulmi L,. (amcricana Riley) Gillette, C. P. Journal 



Ec. Ent. Vol. 2, p. 356 and Fig. 16. "This louse is a real pest 

 upon white elm nearly everywhere that this tree is grown in 

 Colorado." 



1910. Davis, J. J. A tlyist of the Aphididae of Illinois with notes on 



some of the species. Jour, of Ec. Ent. Vol. 3, p. 412. 

 Schisoneura americana. "Not infrequently injuriously abundant." 

 Schisoneura crataegi. "A serious pest of the hawthorns used in 

 ornamental plantings in Chicago." 

 1910. Schisoneura americana, Patch, Edith M. Gall Aphids of the Elm. 



Me. Agr. Exp. Sta. Bui. 181, pp. 223-235. 

 1910. Schisoneura rileyi. Patch, Edith M. Gall Aphids of the Elm. 



Me. Agr. Exp. Sta. Bui. No. 181, pp. 235-238. 

 ■1910. Schisoneura americana. Williams, T. A. Thi; Aphididae of 



Nebraska, p. 16. 

 1910. Schisoneura crataegi. Williams, T. A. The Aphididae of 



Nebraska, p. 19. 

 1910. Schisoneura lanigera. Williams, T. A. The Aphididae of Ne- 

 braska, p. 20. Mere mention. 



1910. S chisoneura rileyi. Williams, T. A. The Aphididae of Nebraska, 



pp. 20-21. "It causes a curling of the leaves similar to S, 

 americana, but the galls can be readily distinguished as those of 

 this species are much more tightly curled than those of S. 

 americana. This latter species is often to be found on the 

 same tree. They can be easily separated, as they differ in size, 

 antennae, venation and other minor points." 



191 1. Schisoneura lanigera. Lohrenz, H. W. Jour. Ec. Ent. Vol. 4, 



pp. 162-170. Ecological and economic study. 



1912a. Schisoneura lanigera. In Bui. No. 195 Me. Agr. Exp. Sta. Re- 

 corded on Crataegus and three species of mountain ash. 



1912b. Schisoneura lanigera {americana'). Patch, Edith M. Science, 

 Vol. 36, p. 30. Progeny of spring migrants from elm reared 

 on apple. ... 



If the elm species of America and Europe are the same, this 

 insect will revert to S chisoneura ulmi L. {lanigera Hausmann) 

 and according to European Aphidists ulmi migrates to the 

 roots of currant for the summer generations where it was 

 described by Buckton as Schisoneura fodiens. Are there two 

 species in Europe known as ulmi, one migrating to currant 

 and the other to apple? 

 1909. Schisoneura ulmi L. {S. fodiens Buckton). TuUgren. Aphi- 

 dologische Studien, pp. 163-169. 



