Overview of the phylogeny, taxonomy and diversity of the leafhopper (Hemiptera: Auchenorrhyncha: Cicadomorpha: Membracoidea: Cicadellidae)

Comprising~ 20,000 described species, leafhoppers (Cicadellidae) are the largest family of sap-sucking herbivores and comprise the largest number of known vectors of plant pathogens of any insect family. Although recent studies of tropical faunas indicate that the vast majority of extant species remain to be discovered, availability of new cybertaxonomic tools is enabling newly trained taxonomists to increase the rate of species discovery. Phylogenetic relationships among leafhoppers remain largely unexplored, but recent published phylogenies based on morphological and molecular data have begun to elucidate the phylogenetic status and relationships of previously recognized tribes and subfamilies. As a result of such studies, several changes to the higher classification have been proposed, including changes to the concepts of subfamilies Cicadellinae, Delocephalinae and Megophthalminae, the groups comprising the majority of known vector species. Taking newly available phylogenetic information into account may help focus the ongoing search for competent vectors on the groups most closely related to known vector species. New molecular phylogenetic and functional genomic tools and techniques may facilitate more rapid and extensive surveys of the microbiota associated with non-pest leafhoppers and promote more comprehensive approaches to the study of the evolution of leafhopper-pathogen-plant associations.