Abstract
New Zealand’s unique ecosystem and geographical isolation have led to a lack of predators, making the arrival of many invasive species in the last century incredibly impactful on our native environment and species as they have not co-evolved to deal with these threats. Amongst the most troublesome invasive species are social wasps, that is Vespula and Polistes species. These invasive pests have been arriving through anthropogenic means since at least the 1940s (Vespula germanica) and most recently, Polistes dominula in 2010. Many strategies have been attempted over the decades for reducing Vespula populations, with toxic baiting currently the best strategy, however, these approaches are yet to remove them from New Zealand. Wasps are especially problematic in the Nelson region where the highest densities of social wasps around the world can be found. Furthermore, baiting is not currently suited to Polistes spp. due to differences in foraging.
Gene drives are a group of technologies being researched worldwide to eliminate pest populations, the general premise being to spread a genetic manipulation across a population eventually causing widespread reduction of a target species, but with the multitude of different gene drives and none yet trialed in hymenopteran species, it is difficult to know if these tools would help us protect our native fauna from these invasive pests.
In this thesis, I review traditional and modern wasp control methods and outline gene drive strategies most relevant for invasive wasps. I then generate the foundational genomic and molecular resources needed to test gene drive feasibility, including transcriptomes, whole genome assemblies, and protocols for in situ hybridisation and immunohistochemistry to characterise germline expression. I provide the first population genomic analysis of Polistes dominula in New Zealand, revealing its introduction history and population structure, and use these data to identify conserved and population-specific germline genes as candidate targets. Finally, I explore germline promoter architecture and propose synthetic promoter constructs as enabling tools for future functional testing.
Together, this body of work establishes the first integrated framework combining ecology, genomics, and molecular biology for the development and evaluation of gene drives in invasive social wasps, laying the foundation for their potential application in New Zealand.