Species-specific primers for the molecular identification of cryptic Bombus species in New Zealand

Abstract

The short-haired bumblebee (Bombus subterraneus) is the rarest of four Bombus species introduced to New Zealand (NZ) from the United Kingdom (UK) in the nineteenth century, and is now extinct in the UK. The NZ population has been proposed as a source for re-introduction of this species to the UK. However, very little is known about the biology of this species and research is hampered by the difficulty of exact identification as it co-occurs with two morphologically similar species (B. hortorum and B. ruderatus). In this study we have developed simple PCR-based molecular identification tools to rapidly, cheaply, and reliably identify not only B. subterraneus, but also two other species: B. hortorum and B. terrestris. We have combined a species-specific internal primer with two non-specific external primers that amplify 426 bp of the Bombus Cytochrome b gene, to produce a presence/absence PCR test that is combined with a positive internal control. The result is a set of molecular tools that will allow us to separate three cryptic species and facilitate basic research on the biology of New Zealand’s rarest bumblebee.