show Abstracthide AbstractThis study aims to estimate a robust phylogeny, infer divergence times and historical biogeography, and perform ancestral state reconstructions of spider flies (Diptera, Acroceridae). Spider flies are some of the most striking insects found worldwide. Many species are important pollinators in certain ecosystems, and larvae of all species are internal parasitoids of spiders. We integrate morphology with next generation sequencing and comparative methods to reconstruct the evolution of both extant and extinct acrocerids. This will allow us to unravel the evolution of spider flies, and provide essential genomic data to broader projects on Diptera phylogeny.