Elevation gradients of flower visitation on a mesa in the Nama Karoo, South Africa

Abstract

We investigated the composition of the insect fauna visiting flowers on the mesa of Tafelberg (Eastern Cape, South Africa). During the season-long study, 1825 individuals of 55 insect species were recorded visiting flowers of 28 species plants within permanent quadrats. Four taxa were
very common as flower visitors, with between 2-300 individual visits recorded (one species from each of the orders of Hymenoptera, Diptera, Lepidoptera and Coleoptera). Two-thirds of all visits were to the composite Pencia punctata (Asteraceae). There was a strong pattern to the diversity of the flower-visiting fauna, with diversity increasing with elevation. This pattern matched the availability of flowers, which were much more abundant on the top of Tafelburg than on its lower slopes.