SECONDARY PARASTTES. 
125 
'Aphidius. 
avenaphis. . Macrosiphum granaria Buck. 
confusus. . 
testaceipes. 
Toxoptera graminum 
. Macrosiphum erigeronensis Thos. 
.Aphis avenx Fab. 
Aphis gossypii Glov. Aphis sp. 
Aphis maidis Fitch. 
Aphis maidi-radicis Forbes. 
Aphis medicaginis Koch. 
Aphis cenotherx Oestl. 
Aphis rumicis Linn. 
Aphis setarix Thos. 
Macrosiphum viticola Thos. 
Macrosiphum granaria Buckt. 
Melanoxantherium sp. 
Macrosiphum sp. on black gum. 
Myzus ribis Linn, on currant. 
Myzus sp. on Hosackia glabra. 
Macrosiphum sp. on Abutilon. 
Macrosiphum cucurbitx Thos. 
Aphidid on Ampelopsis sp. 
Aphidid on Baccharis viminalis. 
Aphidid on Capsella bursa-pastoris. 
Aphidid on Eragrostis sp. 
Aphidid on Kochia sp. 
Aphidid on locust. 
Aphidid on peach. 
Aphidid on pigweed (?). 
Aphidid on plum. 
Aphelinus. 
mail . 
. .Aphis brassicx Linn. 
Aphis monardx Oestl. 
Aphis sacchari (?) Zehntn. 
Aphis setarix Thos. 
Colopha eragrostidis Middl. 
Myzus mahaleb Boyer. 
Pemphigus fraxinifolii Riley. 
Macrosiphum rosx Linn. 
Schizoneura americana Riley. 
Schizoneura lanigera Haussm. 
Tetraneura colophoidea (?). 
nigritus Aphis setarix Thos. 
semiflavus . .Aphis maidis Fitch. 
Aphis gossypii (?) Glover. 
Chaitophorus viminalis Mon. 
Myzus persicx Sulz. 
SECOND ARY PARASITES. 
Megorismus sp. 
Species of the genus Megorismus, it appears, have been previously 
considered as primary parasites. Mr. Parks, however, has con- 
ducted some experiments with a species (fig. 34) at Wellington, 
Kans., and his results clearly indicate that in this case it is a sec- 
ondary parasite. In no instance could he rear it from aphidids 
