Jody Gerdts: Who’s your Mummy: Investigating the host-pathogen relationship between Apis mellifera and Ascosphaera apis in Australia

Three years and over 800 colonies later, we conclude that Australian honey bees are incredibly hygienic and even without intended selection, Australian queen bee breeders produce very hygienic bees. “But how can that be?” asked one beekeeper “Chalkbrood is such a huge problem”. To answer this question, we conducted a nation-wide chalkbrood genotyping survey and found multiple strains of chalkbrood in Australia. We then collected volatiles from infected larvae and discovered a reason why hygienic bees can be infected with chalkbrood disease. Finally, we challenged individual larvae and entire colonies with chalkbrood spores and recorded how they responded giving us insight into individual and colony immunity and virulence of different chalkbrood strains. Each of these steps has informed our understanding of chalkbrood disease in Australia.