Dec. ii, 1916 
Macrosiphum granarium 
465 
DISTRIBUTION IN THE UNITED STATES 
M. granarium undoubtedly occurs throughout the United States 
wherever the small grains are cultivated. The map (fig. 1) indicates 
localities from which the Bureau of Entomology has records of occurrence. 
It will be noted that there are 10 States from which the Bureau has no 
records, though M. granarium undoubtedly occurs in those States. 
FOOD PLANTS OF THE APHID 
This aphid does not confine itself exclusively to its well-known host 
plants, the small grains, but will live and thrive on a number of the wild 
and cultivated grasses. 
Riley (9) listed Agrostis vulgaris [alba], Bromus secalinus , Dactylis 
glomerata, and Poa pratensis as host plants. Besides the plants just 
Fig. i.—M ap showing the distribution of Macrosiphum granarium in the United States as indicated by 
records on file in the Bureau of Entomology, 1916. 
mentioned, the late F. M. Webster recorded it, in notes on file in the 
Bureau of Entomology, as breeding on heads of timothy (. Phleum pra- 
tense) at Mitchell and La Fayette, Ind., in 1889, and in 1890 he recorded 
it as feeding on com (Zea mays) at La Fayette, Ind. In 1904 Pergande 
(11) recorded Elymus sp. as a host. 
A series of experiments conducted at La Fayette, Ind., in 1909, showed 
that M. granarium will breed and thrive in confinement upon the follow¬ 
ing grasses: Bromus commuiatus (?) [racemosus], B. secalinus, Elymus sp., 
Festuca duriuscula [ovina], ‘ F. heterophylla , F. • pratensis [elatior], F. 
tectorum , Juncus tenuis, Lolium italicum, Poa compressa, and P. pra¬ 
tensis. M . granarium was found to breed freely in confinement upon 
Eleusine indica and foxtail (probably Chaetochloa glauca) at Richmond, 
