Preliminary observations of insect pollination in Protea punctata (Proteaceae)

Abstract

Available information on the phylogeny and pollination systems in Protea suggests that bird-pollination is ancestral and occurs in the majority of species, and that there have been several shifts to rodent pollination and a single shift to pollination by cetoniine beetles in this large African genus. Here we report that Protea punctata plants in a population in the Swartberg mountains are pollinated primarily by long-proboscid flies and butterflies. The threadlike pollen presenter on an unusually flexible style facilitates insect pollination in this species. The length of the style matches that of the proboscides of its two most common visitors, the nemestrinid fly Prosoeca longipennis and the nymphalid butterfly Aeropetes tulbaghia. Spectral reflectance of the involucral bracts is similar to that of flowers of other plants visited by long-proboscid flies. P. punctata occupies a recently diverged position in a clade (the “white proteas”) in which all the other species appear to be bird-pollinated, and may represent a shift to insect pollination in the genus.