162 Wisconsin Academy of Sciences, Arts, and Letters, 
spyrothecae, Pemphigus Passerini, 18 60. Gli Afidi, p. 39. 
Populus nigra, P. pyramidalis. 
spyrothecae, Pemphigus Passerini, var. infaustus Ferrari, 1772. 
Ann. Mus. Giv. Stor. Nat. Genova, III, p. 235. 
Populus sp. 
squamosa, Geoica Hart, 1894. Eighteenth Kept. Nox. & Ben. In¬ 
sects Ill., p. 98, fig. 
Arena sativa, Capsella 'bursa-pastor is, EcMnocJiloa crus-galli, 
Phleum pratense, Poe annua, P. pratensis, Trifolium sp., Zea 
Mays. 
squarrosa, Macrosiphum Sanborn, 1904. Kansas Aphididae, p. 77. 
Actinomeris squarrosa. 
stamineus, Aphis (Pemphigus) Haldeman, 1859. Proc. Boston, 
Soc. Nat. Hist., VI, p. 403. 
Acer saccharinum. 
Stanley!, Macrosiphum Wilson, 1915. Proc. British Columbia Ent. 
Soc., No. 5, p. 82, fig. 
Sambucus glauca. 
staphyleae, Rhopalosiphum Koch, 1854. Die Pfianzenlause Aphi- 
den, p. 32, fig. 
Cystopteris montanaf, Heliotropium peruvianum, Staphylea pin- 
nata. 
steinheili, Pterocomma Mordwilko, 1901. Horae Soc. Ent. Ross., 
XXXIII, p. 350. Oladohius. 
Populus sp., Salix alba. 
*stellariae, Brachycolus (Hardy), 1850. North British Agricult¬ 
urist, II, p. 788. Aphis. 
Agrostis alba, A. vulgaris, Cerastium triviale, Fastuca ovina, Hol- 
cus lanatus, H. mollis, Stellaria graminea, 8. holostea, 8. media, 
Triticum sp. 
stellarlae, Macrosiphum Theobald, 1912. The Trans. Second Ent. 
Congress, p. 387; also 1913, Jour. Econ. Biol. VIII, No. 3, 
p. 141. 
8tellaria graminea. 
stevensis, Ohaitophorus Sanborn, 1904. Kansas Aphididae, p. 36. 
Populus deltoides, P. monilifera. 
