6 
BULLETIN 112, U. S. DEPARTMENT OF AGRICULTURE. 
winged female has its wing venation much like that of Aphis pomi; 
the cornicles are black, tapering and reaching almost to the tip of 
body, and the abdomen is rather conspicuously marked by a large 
black patch on the dorsum. 
HOST PLANTS. 
Aphis avence has been recorded from a large number of plants, par- 
ticularly of grasses. Owing to the confusion with the larger grain 
aphis (Macrosiphum granarium) in some of the literature, it is im- 
possible in many cases to determine which species of plant-louse was 
meant, and consequently the following list includes only those plants 
in cases where the identity of the aphis is reasonably certain. This 
list does not include all of the plants upon which this species has been 
found in Europe. 
GRAMINE^. 
Wheat, Triticum vulgar e 
Triticum dicoccum x 
Rye, Secale cereale 
Oat, Avena saliva 
Wild oat, Avena fatua 2 
Tall oat grass, Arrhcnatherum ela- 
tius 3 > 4 
Barley, Hordeum rulgare 
Two-rowed barley, Hordeum distichon * 
Wall barley, Hordeum murinum 4 
Timothy, Phleum pratense 
Canada blue grass, Poa compressa 
Kentucky blue grass, Poa prate nsis 
Annual or dwarf meadow grass, Poa 
ann ua * 
Rough-stalked meadow grass, Poa 
trivialis 
Crab grass, Syntherisma sanguinale 
Upright chess, Bromus racemosus 
Rescue grass, Bromus lonioloides 
Cheat, Bromus secalinus 3 > 4 
Hungarian brome grass, Bromus in- 
ermis 3 > 4 
Orchard grass, Dactylis glomerata 
Italian rye grass, Lolium multiflo- 
rum 3 > 4 
Perennial rye grass, Lolium per enne 3 . 4 
Redtop, Agrostis alba 3 > 4 
Red fescue, Festuca rubra 3 > 4 
Sheep's fescue, Festuca ovina 3 > 4 
Meadow fescue, Festuca pratensis 
[=elatior] 3 . 4 
1 Recorded by Mordwilko as hosts of Aphis padi Kalt. — auenie Fabr. 
2 Recorded by Fabricius ; so far as known, tbere is no record on tbis plant from 
America. 
3 In 1909 Mr. T. H. Parks, at that time connected with the Bureau of Entomology, con- 
fined this species with various plants and found that it would breed contentedly and freely 
on these plants. Other plants tried, and which the aphides refused, are Muhlenbergia, 
Af/ropyron occidentale, Panioum rirgatum, and P. bulbosum. 
i Recorded here for the first time. 
5 Recorded as hosts of this species by Passerini. 
geamine.e — continued. 
Hard fescue, Festuca ovina durius- 
cula 3 , 4 
Reed canary grass, Phalaris arundi- 
nacea 3 > 4 
Melic grass, Melica bauhini 1 
Melica penicillaris % 
Johnson grass, Andropogon halepensis 5 
Broom corn, Andropogon sorghum var. 
Sorghum, Andropogon sorghum var. 
Koeler's grass, Koeleria cristata x 
Wild rye, Elymus geniculatus [=are- 
narius) x 
Virginia wild rye, Elymus virginicus * 
Nodding wild rye, Elymus canadensis 4 
Corn. Zea mays 
Teosinte (Euchlaena mexicana) 3 > 4 
TYPHACEiE. 
Cat-tail, Typha latifolia" 
AMMIACE^E. 
Celery, Apium graveolens 
COMPOSITE. 
Tickseed, Coreopsis sp.? 
MALACE^E. 
Apple, Malus malus 
