Dr James Bickerstaff¹, Dr Hermes Escalona¹

¹CSIRO ANIC, Canberra, Australia

Biography:

James Bickerstaff is a postdoctoral researcher at the Australian National Insect Collection, CSIRO. He completed his PhD at the Hawkesbury Institute for the Environment, Western Sydney University in 2021 where he worked on the phytogeography and microbial ecology of Australian ambrosia beetles. He specialises in the systematics, genomics and microbial ecology of bark and ambrosia beetles. He has been working on genome sequencing and comparative genome evolution of the global Scolytinae fauna to understand the interplay between genomics and life history traits, how this has led to their success and how this contributes to their invasion.

Abstract:

The Polyphagous Shot Hole Borer, Euwallacea fornicatus, is a high priority pest species that has recently been introduced to Perth, Western Australia. The PSHB has been recorded to attack over 680 tree species throughout its native and introduced range. The ambrosia beetle is associated with the pathogenic fungus, Fusarium euwallaceae, both of which cause significant economic and ecological damage to managed and native ecosystems and agricultural areas. Few genetic resources exist for the PSHB and these are crucial for effective management of the pest as well as understanding why the species is an effective invader. This study provides the first chromosome-level genome assemblies of these species, offering insights into their genetic makeup and evolutionary history.

Utilizing long-read PacBio HiFi reads and Arima Hi-C data, we have constructed high-quality chromosome level genome for the species and for E. similis. Our assemblies highlight structural variation between these haplodiploid inbreeding species compared to outbred species of Scolytinae. Further, we characterise a high level of repeat and transposable elements that may contribute to the evolution of genome architecture in these species.

The chromosome-level genome assemblies of E. fornicatus and E. similis will provide a foundation for future studies on the genetic factors contributing to the success of invasive ambrosia beetles and offer valuable resources for the development of targeted management and control strategies. Furthermore, they will contribute to the understanding of how life history traits of species contribute to genomic and chromosomal evolution.