ASSESSMENT OF THE GENETIC BASE OF TASMANIAN BUMBLE BEES (BOMBUS-TERRESTRIS) FOR DEVELOPMENT AS POLLINATION AGENTS

The bumble bee Bombus terrestris has spread over much of the island st ate of Tasmania since it was first found there in 1992. Horticulturist s in Tasmania are hoping to use local, commercially raised colonies fo r use as pollinators in glasshouses. In this experiment 100 field-capt ured queens were confined under conditions suitable for colony establi shment to check for the prevalence of diploid male production, an indi cation of inbreeding. The ratio of males to workers at the beginning o f colony development was used as an indicator. Results of this experim ent show that the Tasmanian bumble bee population is presently very in bred. About 50% of the adult-producing colonies produced initial sex r atios consistent with male diploidy, which suggests that the entire Ta smanian population may be descended from one inseminated queen. The im portation of new genetic material may be necessary to sustain commerci al breeding of B. terrestris in Tasmania.