Sipha

Wieczorek, Karina, 2011, Descriptions of four hitherto unknown or little-known morphs of Siphini (Hemiptera, Aphidoidea: Chaitophorinae), Zootaxa 2756, pp. 53-60 : 58

Key to known alate viviparous females of the subgenus Sipha

1. Body not covered with rows of spinules.................................................................... 2

-. Body densely covered with rows of short, robust spinules...................................................... 3

2. Antennae 0.70 mm long, 0.48 times body length.................................... S. (S.) agropyronensis (Gillette)

-. Antennae 1.02–1.18 mm long, 0.60–0.62 times body length.................................... S. (S.) flava (Forbes)

3. Apical segment of rostrum 0.25–0.27 times antennal segment III and 0.50 times HT II........ S. (S.) glyceriae (Kaltenbach)

-. Apical segment of rostrum 0.45–0.52 times antennal segment III and 0.64–1.00 times HT II........ S. (S.) littoralis (Walker)