Towards a time scale for scales: Divergence time estimation of major lineages in Coccoidea (Hemiptera: Sternorrhyncha)

The plant-sucking scale insects (Hemiptera: Coccoidea) are amongst the most damaging pests in agriculture and forestry. Despite a sophisticated and specialized taxonomy, obtaining a dated phylogeny of the Coccoidea has remained unexplored because of a unique situation in this group: their systematics is solely based on the highly reduced adult females, whereas fossils are mainly preserved as the morphologically dissimilar adult males. This complicates understanding how this group has evolved in relation to the angiosperms, and whether their host plants have triggered a radiation of the main families. Fortunately, recent studies of adult males across the Coccoidea are now allowing a comparison amongst Recent and fossil taxa. Moreover, male Coccoidea are both diverse and abundant in most deposits of amber around the world, providing one of the best stratigraphic records of any major group of phytophages for the past 130 million years. We use a combined approach to incorporate the fossils of 15 extinct families and assess their relationships with Recent families. Additionally, a divergence time estimation of major lineages of scale insects is presented, with a discussion of current challenges in the study of both fossil and recent taxa in this superfamily.