Mating preference in the commercially imported bumblebee species Bombus terrestris in Britain (Hymenoptera: Apidae)

Abstract

Commercial trade of bumblebees in Europe results in different subspecies of Bombus terrestris being shipped into regions where they are not native. Although previous studies have shown that these subspecies will interbreed, none have assessed mating preference of the different populations. This study examines the mating preferences between two geographically isolated populations of B. terrestris which have unnaturally been brought together through the commercial trade in bumblebees. Under controlled choice conditions, mating between commercially imported B. t. dalmatinus (from South-eastern Europe) and native British B. t. audax was non-random. Commercially imported gynes (unfertilised queens) preferred to mate with males from the same population (71% of matings). In light of the continued escape of imported gynes and males, these results indicate that there is a possibility of establishment of South Eastern European B. t. dalmatinus in Britain, and that hybrids will also occur. The ecological risks of such an establishment are discussed.