Extant Psylloidea, or jumping plant-lice, is a group of sternorrhynchous insects comprising 3000 – 3500 described species (
Burckhardt et al., 2005; Ouvrard et al., 2008). Mifsud & Burckhardt (2002) suggested that the number of actually existing species may be more than twice the number of the described species.

At the species level, psylloids exhibit very narrow host-plant ranges, particularly at the larval stage (Burckhardt et al., 2006; Yang & Raman, 2007). This restriction to particular host taxa is also often found in whole psylloid genera or families (Burckhardt & Lauterer, 1989). The extant world fauna of Psylloidea is associated almost exclusively with dicotyledonous plants (Hodkinson, 1974; Burckhardt, 2005), with a few species developing on monocotyledonous angiosperms and only four species on conifers (Burckhardt, 2005). This suggests that psylloid diversification coincided with or closely followed that of the angiosperms in the Cretaceous. Psylloids have a worldwide distribution, but are most diverse in tropical and subtropical areas (Burckhardt, 1987; Hollis, 2004).

(Extract from: Ouvrard et al., 2010).