338 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



THE MIGRATORY HABITS OF MYZUS RIBIS (LINN.) 



By C. P. Gillette and L. C. Bragg 



This is one of the best known aphides in both Europe and the United 

 States, occurring upon the leaves of the various species of Rihes, espe- 

 cially the common red currant, but also known to attack the leaves of 

 the European black currant, the Rocky Mountain wild currant, R. 

 aureum, and occasionally the gooseberry. 



Linnaeus gave a very good description of this louse including the red 

 leaf galls which it produces, so we are reasonably certain of the species 

 he worked with. It has long been known that it leaves the currant 

 bushes during the middle of the summer, but no one has definitely 

 determined the alternate hosts. 



Kaltenbach and Koch may have had this species under observation 

 when studying galeopsidis on Stachys, which we have demonstrated is 

 a common summer host of this species in Colorado. 



Buckton, vol. II, pi. 39, fig. d, has evidently confounded the red 

 leaf galls of this species with the work of Rhopalosiphum ribis, a fact 

 referred to by Schouteden in his "Catalog of the Aphididse of Bel- 

 gique," p. 236. 



Koch put this species in the genus Rhopalosiphum, probably because 

 there is a slight enlargement of the cornicles toward the distal ends 

 where the diameter is greatest. 



Dobrovliansky, in Review of Applied Entomology, 1914, p. 81, is 

 quoted as saying that this aphid is injurious to the black currant, but 

 says nothing of the possibility of its having a different summer host. 



Dr. Patch, in Bulletin 225 of the Maine Experiment Station, p. 55, 

 1914, mentions this as a common louse upon the currant in Maine 

 and considers it a migrating species, but says that the alternate host 

 plant is unknown. 



Prof. H. F. Wilson, in his paper, "Biennial Crop Pests and Horti- 

 cultural Report of the Oregon Agricultural College and Experiment 

 Station," p. 94, 1912, speaks of this as a migrating species and gives a 

 characterization of its different stages, including the egg, upon the 

 currant, but does not suggest the summer hosts. He also mentions 

 the gooseberry as an occasional host plant. 



Van der Goot, in his paper on Blattlaus-Arten, Overgedrukt uit het 

 Tigdschrift voor Entomologie, Deel LV, 1912, p. 72, considers M. ribis 

 a migrating species and says it is possible that his M. lamii might be 

 the migratory form of ribis. 



Van der Goot, also, in "Beitrage zur Kenntnis des Hollandischen 

 Blattlause," p. 113, 1915, reports the fall migrants of M. galeopsidis 

 coming to the currant and the oviparous females laying eggs upon the 



