Bumblebees: implications of a new super-pollinator in mainland Australia.

Large feral populations of the European honey bee have been present in the Australian environment for at least 150 years and it is now impossible to evaluate the impacts these bees have had on our flora, native or introduced. Honey bees are efficient pollinators but some groups, especially Boraginaceae, Lamiaceae and Fabaceae, are more efficiently pollinated by bumblebees, either because of their weight, which allows them to ‘trip’ the flower, giving the bee access to the nectar but also releasing pollen onto the bee, or as ‘buzz’ pollinators, where they shake out pollen enclosed inside a pollen cone. The European large earth bumblebee Bombus terrestris has been introduced into many countries worldwide by horticulturists in order to improve fruit set in greenhouse crops. Feral populations of B. terrestris are established in Japan, Chile, New Zealand and Tasmania. It is inevitable that the bumblebee will reach mainland Australia and establish feral populations here. This paper reviews the world literature on B. terrestris, considers probable impacts on seed production in weedy plants and proposes research to monitor and evaluate these impacts.