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 



repens, 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 hirtits, food plant of Toxoptera 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 Aphidencyrtics aphidiphagus 126 



Pachyneuron sp 127 



Aphidencyrtics aphidiphagus, hosts 126-127 



secondary parasite of spring grain-aphis 126-127 



Aphidid on Ampelopsis sp. , host of Aphidius testaccipes 116, 125 



Baccharis viminalis, host of Aphidius testaceipes. 117, 125 



bluegrass, host of Aphelinus semiflavus 123 



Capsella sp., host of Aphidius testaceipes 116 



Chenopodiwn 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 testaccipes 116, 125 



Aphidius avenaphis, parasite of Macrosiphum cranaria 125 



spring grain-aphis 103, 122 



26675°— Bull. 110—12 10 145 



