Sodium and potassium concentrations in floral nectars in relation to foraging by honey bees

Abstract

Sodium and potassium concentrations have been measured in nectar from a variety of flowering plants visited by honey bees (Apis mellifera capensis). In 18 plant species the mean sodium concentration was 9,8 ± 1,4 mmol (± S.E.), and the mean potassium concentration was 18,7 ± 4,3 mmol. These results are compared with nectar ion concentrations in carpenter bee and hummingbird flowers. Analysis of honey bee body fluids showed that, although haemolymph ion concentrations were closely regulated, the levels of sodium and potassium in the urine did not necessarily reflect those in the nectar being gathered.