INDEX. 
Page 
Abutilon, food plant of Macrosiphum sp 117, 125 
Adalia flavomaculata, enemy of spring grain-aphis 18, 129 
Agropyron occidentale, food plant of spring grain-aphis in America 32, 41, 42, 43 
rcpens, food plant of spring grain-aphis in America 42, 43 
Europe 41,43 
tenerum, food plant of spring grain-aphis in America 42, 43 
Alfalfa. (See Medicago sativa.) 
Allograpta obliqua, enemy of Macrosiphum granaria 132 
probable enemy of spring grain-aphis 132 
Allotria sp. , hosts 128 
in bluegrass infested by spring grain-aphis at Washington, D.C. . 37 
secondary parasite of spring grain-aphis 128 
Alopecurus geniculatus, food plant of spring grain-aphis in America 41, 43 
Ampelopsis sp. , food plant of aphidid 116, 125 
Andropogon hirtus, food plant of Toxoptcra graminum in Africa 43 
Andropogon sp. (See Sorghum.) 
Ants, enemies of Aphidius sp 136 
spring grain-aphis 136 
Aphelinus mali, hosts 122, 125 
parasite of spring grain-aphis 103, 122-123, 125 
nigritus, life history and habits, notes 124 
parasite of Aphis setarix 125 
spring grain-aphis 103, 122, 123, 124, 125 
semiflavus, hosts 125 
parasite of spring grain-aphis 103 
sp. , probable host of Aphidencyrtus aphidiphagus 126 
Pachyneuron sp 127 
Aphidencyrtus aphidiphagus, hosts ' 126-127 
secondary parasite of spring grain-aphis 126-127 
Aphidid on Ampelopsis sp., host of Aphidius iestaccipes 116, 125 
Baccharis viminalis, host of Aphidius testaceipes. 117, 125 
bluegrass, host of Aphelinus semiflavus 123 
Capsella sp. , host of Aphidius testaceipes 116 
Chenopodium album, host of Aphidius testaceipes 116 
Eragrostis sp. ,• host of Aphidius testaceipes 117, 125 
Kochia scoparia, host of Aphidius testaceipes 116 
sp. , host of Aphidius testaceipes 125 
locust, host of Aphidius testaceipes 116, 125 
Panicum sp. , host of Aphelinus mali 123 
peach, host of Aphidius testaceipes 125 
pigweed (?), host of Aphidius testaceipes 125 
plum, host of Aphidius testaceipes 116, 125 
Aphidius avenaphis, parasite of Macrosiphum (ranaria 125 
spring grain-aphis 103, 122 
26675°— Bull. 110—12 10 145 
