Fertilisation of Flowers by Insects

Abstract

IN my last article on Alpine Gentiana species, I supposed that the chief, if not the only fertiliser of G. bavarica and verna might be Macroglossa stellatarum with its proboscis of 25-28 mm. length. Yesterday, near the Albula pass, I was happy enough to confirm this supposition by direct observation. Altogether I saw five specimens of Macroglossa stellatarum at work, one on Gentiana bavarica and verna, three on Primula integrifolia, and one on Viola calcarata, each of them in a few minutes fertilising some hundreds of flowers. For instance, the last of my five Macroglossa specimens, which I observed with the watch in my hand, in less than four minutes visited 108, and in other 63/4 minutes 194 flowers of V. calcarata.