The taste of nectar - a neglected area of pollination ecology

Nectar is an important biological resource that is utilized by a wide range of animals as a food source. Amino acids are the second most abundant class of compound (after sugars) to be found in nectar. In foraging for nectar, animals carry out the vital role of pollination. Many animal taxa visit flowers, but the most abundant pollinators are insects. Although amino acids are detectable by insects, little work has focussed on the role of taste in the ecology of pollination (with most studies concentrating on foraging choice). The idea that different amino acids elicit different responses in insect taste receptors was used to characterize nectar samples from 65 plant species from a wide range of families according to their amino acid profile (determined by high performance liquid chromatography). A ternary classification system was used to map the amino acids present in nectar samples. There is a wide range of taste profiles with most plant species having their own characteristic taste value. How nectar tastes to pollinating insects is of great importance in understanding the foraging choices of insect pollinators and there are many avenues that remain to be explored.