Untangling the Beet Leafhopper (Hemiptera: Cicadellidae) species complex: a case study in integrative taxonomy

Abstract The Old World leafhopper genus Neoaliturus Distant includes the ‘beet leafhopper’ (N. tenellus Baker), a widespread vector of several plant pathogens originally described from the southwestern USA but native to the Mediterranean region. Previous authors suggested that this species, traditionally diagnosed based on the morphology of male genitalia, may be a ‘complex’ comprising more than one biological species. A recent molecular phylogeny of Neoaliturus recovered 6 well-supported monophyletic groups (OTUs) among samples identified morphologically as belonging to the N. tenellus complex but it was not clear whether these individual clades represent distinct species or reflect population structure within a single species. Here, morphometric and acoustic analyses are used to corroborate the status of these OTUs as distinct species. Vibrational signals analysis of male courtship calls and morphometric analyses of the male subgenital plate and style support the recognition of all 6 N. tenellus complex OTUs as distinct species. Three are described here as new species and the remaining 3 conform to known taxa including one previously described species (N. tenellus), and 2 formerly treated as subspecies, N. tenellus ambiguosus (Young and Frazier) and N. dubiosus infirmus (Young and Frazier). Both subspecies are here elevated to species rank, becoming N. ambiguosus and N. infirmus, respectively. Formal descriptions of the 3 newly recognized species, N. acuminatussp.n., N. ozitaliasp.n., and N. robustostylussp.n., are provided, along with redescriptions of the remaining species of the N. tenellus complex.