Tamalia gall aphids and their host plants, Arctostaphylos species, as part of California’s landscape: The California Conservation Genomics Project (CCGP)

The University of California-led Conservation Genomics Project (CCGP) is an effort to: 1) identify biological populations harboring the greatest genomic diversity across the state’s ecological regions (eco-regions); 2) identify those eco-regions likely to be resilient in the face of climate change and novel land-use patterns; 3) gather data on the genomic robustness of ecological keystone species. The aphid, Tamalia coweni (Aphididae), by inducing galls on a range of Arctostaphylos (Ericaceae) shrubs in California’s landscapes, acts as a keystone species. It supports a variety of associated arthropods, including socially parasitic Tamalia inquiline aphids, two specialist dipteran predators, opportunist predatory anthocorid bugs, gregarious Aprostocetus larvae (Eulophidae), and thigmotactic thrips. As seen in the variety of gall shape, size, and texture among host plant species, gall induction by Tamalia aphids is a unique manifestation of gene expression in both host plant and insect. To characterize the genetics of T. coweni at a landscape level, we have created a chromosome-level reference genome for T. coweni. At a population level, we are applying genome re-sequencing techniques for sampling Tamalia galls comprehensively across California’s eco-regions. Ultimately we will use these data to identify the regions and populations with the highest potential for safeguarding genetic and ecological diversity in perpetuity. Here we present an update on the project.