Genomics of host races in Tetranychus urticae

The genomes of co-occurring strains of the two spotted spider mite, Tetranychus urticae, in The Netherlands were sequenced. Genetic studies revealed that a subset of the strains could not be crossed (or at least did not show full viability). An analysis of genetic differences among groups that could or could not interbreed revealed substantial genetic differentiation. The resulting resource provides an opportunity to study the genes and alleles that lead to (or maintain) genetic differentiation between arthropod host races that can exist together in space.