Colonisation hypotheses. Relative timing of the common ancestors of Acacia thrips in relation to Acacia. The green branches indicate the Acacia clade and the black branches thrips. We calibrated the relative timing of the two clades at the nodes where a parallel divergence (codivergence) event occurred between them . Explanations for hypotheses: H0) contemporaneous origin of Acacia and Acacia-thrips MRCA; H1) multiple independent colonisations of Acacia and extinction of ancestral hosts; and H2) host shifting from more distantly related natal host.