A06
A06
Role of niche choice in rapid host adaptation of Colorado potato beetle
Shuqing Xu
In a heterogeneous environment, individuals can have different responses and select different microenvironments (niche choice) that increase their fitness. While evolutionary theories predict that individual niche choice can facilitate rapid adaptation in a heterogeneous environment and maintain genetic diversity, direct empirical evidence is rare. This is mainly due to the difficulties in directly assessing multi-generational fitness consequences of niche choice in evolutionary processes. As genetic trade-offs, pleiotropy and microbiota can also confound and affect niche choice, it remains currently unclear to which extent individualised niche choice can contribute to rapid adaptation and the maintenance of genetic diversity. To address these questions, we will investigate how niche choice affects the evolutionary process of insecticide resistance and gut microbiota in Colorado potato beetles (Leptinotarsa decemlineata, CPB), using an integrative approach that involves experimental evolution, trait manipulation, metagenomics and individual-based modelling. For the niche choice behaviour, we will focus on oviposition choice, one of the most important traits of maternal care in phytophagous insects. Specifically, we will first evolve populations of CPB that consist of six genotypes in a greenhouse for twelve generations under a full factorial design: presence/absence of insecticide-treated plants and presence/absence of oviposition choices. Second, we will quantify the evolutionary changes in oviposition choice, insecticide resistance and population fitness. The CPB fitness will be compared between populations evolved with and without oviposition choice. Third, we will sequence the evolved populations and their gut microbiota to investigate the effects of oviposition choice on genomic features and microbiota that are associated with host plant adaptation. Fourthly, using an individual-based modelling approach, we will explore under which conditions oviposition choice can affect the process of host plant adaptation. Together, this project will directly assess the effects of niche choice on rapid adaptation in a multicellular eukaryote. The outcomes will shed light on how phytophagous insects rapidly adapt to different host plants in nature and may facilitate the development of sustainable crop management strategies, a pressing challenge in today's society.
