Comparing levels of geitonogamous visitation by honey bees and other pollinators

By Travis and Kohn

A honey bee foraging on White Sage (Salvia apiana)

Honey bees (Apis mellifera) can be found on all continents exlcuding Antarctica, and are the most common flower visitor in both agricultural and natural settings worldwide. Pollinator importance and effectiveness has been historically calculated as the number of pollen grains deposited or the number of fruits or seed produced after a single visit by a pollintor onto a previously unvisited flower. However, the number of flower visits per plant a floral visitor makes before moving onto another plant (geitonogamous visitation) may also be of interest for successful reproduction in both self-compatible and -incompatible plants. Here we show that on average, honey bees visit more flowers per plant compared to the average among all pollinators, and as honey bees become more numerically abundant, non-honey bee flower visitors visit less flowers per plant. This study provides evidence that while the number of pollen grains depostited or the number of fruits/seeds produced informs a pollinator's importance and/or effectiveness, the number of flower visits per plant should also be taken into account. 

Read the scientific publication in JPE.