Sugar preferences of Camponotus modoc and Myrmica rubra

A stable source of carbohydrates is essential for the longevity of ant
colonies. Foraging ants must select among carbohydrate resources, such as
aphid honeydew, that vary based on sugar type, volume and concentration.
Using Western carpenter ants, Camponotus modoc, and European fire ants,
Myrmica rubra as model species, we tested the hypothesis that ant foraging
on aphid honeydew is driven by aphid-specific sugars (unique sugars
biosynthesized by aphids) and that ants will selectively consume
particular mono,- di-, and tri-saccharides. In choice bioassays, we
offered whole ant colonies with aqueous sugar solutions and measured their
consumption. In C. modoc, common sugar constituents (rather than
aphid-specific sugars) and sugar concentration affected consumption by
ants. Colonies of C. modoc and M. rubra preferred fructose to other
monosaccharides (xylose, glucose) and sucrose to other disaccharides
(maltose, melibiose, trehalose). Conversely, when offered a choice between
the aphid-specific trisaccharides raffinose and melezitose, C. modoc and
M. rubra favored raffinose and melezitose, respectively.