136 Wisconsin Acadeyny of Sciences, Arts, and Letters. 
popuineus, Thecabitis Koch, 1857. Die Pharizenlau&e Apliiden, p. 
295, fig. 
Populus nigra. 
populus-grandiclentata, Aphis Rafinesque, 1818. Amer. Mon. Mag. 
& Critic. Rev., Ill, p. 16. 
Populus grandidentata. 
populus-trepida, Aphis Refinesque, 1818. Amer. Mon. Mag. & 
Critic. Rev. Ill, p. 16. 
Populus tremuloides. 
porosus, Myzus Sanderson, 1900. Twelfth Rept. Del. Agr. Exp. 
Sta., p. 205. 
Fragaria sp. 
portschinskyi, Macrosiphum Mordwilko, 1909. (Trudi) Bur. Ent. 
(Dept, of Agr.)? VIII, No. 3, p. 11. 
Spiraea ulmaria. 
portulacae, Myzus Macchiati, 1883. Bui. Soc. Ent. Ital., XV, p. 
235. 
Portulaca oleracea. 
iwschingeri, Prociphilus Holzner, 18‘74. Stett. Ent. Zeit. XXV, 
pp. 221, 321, 324, fig. Pemphigus. 
Ahies dalsamea, A. fraseri, Pinus sp. 
potentillae, Aphis Walker, 1850. Ann. Mag. Nat. Hist. ser. 2, VI, 
p. 122. 
Potentilla anserina. 
potentillae, Macrosiphmn (Oestlund), 1887. Aphididae of Min¬ 
nesota, p. 83. Nectarophora. 
Potentilla anserina. 
potentillae, Myzus Williams, 1911. Aphididae of Nebraska, p. 
65. 
Potentilla anserina, P. arguta. 
potentillae, Myzus Oestlund, 188 6. Aphididae of Minnesota, p. 
30. 
Potentilla anserina. 
praecox, Chermes Cholodkovsky, as a var. of C. lapponicus Cholod- 
kovsky which see 
