Honeybee invaders escape inbreeding depression (#860)
Inbreeding depression often occurs in small populations. This is a problem when the population is one we wish to conserve, but should be a blessing when the population is an unwanted invasive. For example, some social insects are highly invasive pests, threatening agricultural services and the environment. Social insects also tend to be highly susceptible to inbreeding depression due to their haplo-diploid sex determination system, in which individuals homozygous at the complementary sex determiner, csd (i.e. diploid males) either do not survive to adulthood or are infertile as adults. We investigate the consequences of inbreeding in a recent social insect invasion in Australia: the Asian Hive Bee (Apis cerana). We first test the conjecture that today’s invasive population arose from a single founder colony arriving in Cairns in 2007. We then determine csd diversity of colonies sampled throughout the timeline of the invasion (2007 to present). Finally, we consider the role that thelytoky – a form of asexual reproduction in which unmated queens or workers produce daughters – has played in the spread of A. cerana’s population. Has this uncommon reproductive tactic assisted these honeybee invaders in escaping the burden of inbreeding?