Dr Rachael Dudaniec1, Dr Cecillia Kardum Hjort1, Sabrina Haque1, Hasinka Gamage, A/Prof Fleur Ponton1, Prof Ian Paulsen1, Francois Encinas-Viso, Prof Andrew Allen, Prof Henrik Smith, Dr Josephine Paris2

1Macquarie University, Sydney, Australia, 2Marche Polytechnic University, Italy

Biography:

Rachael Dudaniec leads the Landscape Genetics Lab and is an ARC Future Fellow in the School of Natural Sciences at Macquarie University. Rachael investigates the ecological and evolutionary genetic processes that determine successful invasions, range expansions, host-parasite interactions, and the persistence of threatened species. Her research employs diverse genomic and metagenomic approaches to examine how organismal health and the environment interact to enable species to persist under climate change and other anthropogenic disturbances.

Abstract:

Understanding how genetic and morphological variation across invasive insect ranges is linked with adaptation in novel environments can assist with predicting future spread. Furthermore, the health of invasive insects is intricately connected to the gut microbiome and diet. Despite being founded by just a few individuals, B. terrestris has in less than 30 years successfully spread across Tasmania, becoming abundant and competitive with native pollinators. Here, we examine for morphological divergence since invasion, and how environmental factors limit or facilitate gene flow, selection, and diversity of the gut microbiome in B. terrestris. We collected B. terrestris workers from 16 sites across Tasmania and using DNA sequencing and metabarcoding approaches, examined how genetic variation, morphology and gut microbial diversity and the diversity of foraged pollen associate with local site environmental variables. There was overall weak morphological divergence across Tasmania, but body size was positively associated with the % urban land cover and proboscis length decreased with increasing % pasture. Further, we found high gene flow and low genetic diversity, yet significant spatial variation in effective migration rates. Genetic signatures of a recent population expansion were evident, extending from the south to north. Selection signatures were found in relation to precipitation, wind speed and wing loading. Candidate loci were annotated to gene functions related to cuticle water retention and insect flight muscle stability. The composition and diversity of the gut microbiome was significantly predicted by site annual precipitation and % pasture. Pollen biomes were comprised mostly of introduced plants, and gut microbial diversity was explained by interactions between pollen diversity, wind velocity and % pasture. This study reflects the highly adaptable nature of B. terrestris and provides further understanding of how pollinator-environment interactions influence bee health, the invasive capacity of bees, and the evolutionary processes that determine their success.