Marginal abdominal tubercles
Tubercles arranged singly on the lateral sides of abdominal segments
The function of marginal abdominal tubercles is not fully understood, although ant-attended species often have large tubercles, suggesting they may be points of purchase as ants grasp the aphids in their mandibles. The distribution of marginal tubercles on the aphid's abdomen can help identify aphids. For example, species in the tribe Aphidini, including Aphis and Rhopalosiphum have tubercles on abdominal segments 1 and 7. Although other aphids may have marginal abdominal tubercles, they do not have them on both segments 1 and 7.