Empoasca Walsh

Southern, Phillip Sterling, 2010, Eight new species of Empoasca (Hemiptera: Cicadellidae: Typhlocybinae: Empoascini) from Peru and Bolivia, Zootaxa 2524, pp. 1-23 : 3

Genus Empoasca Walsh

Empoasca ( Walsh 1862) : 149.

Type species E. viridescens Walsh (a synonym of Tettigonia fabae Harris ) Synonyms: Asymmetrasca Dlabola 1958: 51 ; Dworakowska 1971: 275 Sabourasca Ramakrishnan & Menon 1972: 183 ; Dworakowska 1977: 283 Solanasca Ghauri 1974: 425 , new synonym

Diagnosis. Species of Empoasca may be distinguished from other Empoascini by the following combination of features: head in anterior view <2X taller than greatest width, lateral frontal sutures extended well dorsad of antennal pits but not to midline, ocelli well separated from eyes; crown in dorsal view with anterior and posterior margins subparallel or with anterior margin somewhat more produced, width between eyes greater than eye width, posterior margin of eye extended to posterior head margin, coronal suture not extended to crown apex; forewing with veins ScR separate from M basad of RA, inner apical cell distinctly tapered distally; hind wing vein CuA completely confluent with MP (only one large closed apical cell present); hind tibia row AV with 6 or fewer macrosetae; male pygofer lobe separated from base dorsally by membranous cleft, macrosetae absent, ventral appendage usually present; subgenital plate with or without lateral basal lamella, apex bent dorsad and compressed distally, extended beyond pygofer apex, group C macrosetae multiseriate basally and uniseriate distally, group B well differentiated, group A usually differentiated from group B, group D setae evenly distributed; connective triangular or trapezoidal, stem very short or absent, median anterior lobe absent; style usually simple without distinct preapical lobe, apex tapered, curved laterad, and bearing several small teeth, preapical setae sparse or absent; aedeagus with preatrium well developed, with or without processes, dorsal apodeme absent or poorly developed; anal tube usually with well-developed (rarely reduced and lobelike) pair of basolateral hook-like processes (anal hooks) extended ventromesad of pygofer lobe.

Notes. Empoasca , by far the most speciose genus of Empoascini , is presently poorly defined and doubtfully monophyletic. Previous authors have recognized distinctive groups of species within the genus and some of these were subsequently placed in separate genera or subgenera, but much more work, including phylogenetic analysis and improved documentation of tropical faunas will be needed before a more stable classification is possible. DeLong (1931) placed the North American species into four subgenera, one of which ( Idona ) was subsequently transferred to tribe Dikranaeurini ( Young 1952), but subsequent New World workers (including DeLong in his later papers) did not recognize subgenera. The present definition of the genus excludes Kybos Fieber and Distantasca Dworakowska , treated variously by recent authors either as subgenera of Empoasca or as separate genera (cf. Dworakowska 1972, Dworakowska & Viraktamath 1975, Dworakowska 1976, Oman, et al. 1990, Muehlethaler, et al. 2009). Species of Kybos , distributed largely in the Holarctic region, are readily distinguished by the conspicuous tuft of elongate setae on a thickened preapical section of the male style and by their larger size and usually short, broad head. Species of Distantasca , apparently restricted to the eastern Palearctic and Oriental regions, differ from Empoasca in having two conspicuous tufts of very long, fine setae on the male subgenital plate. Solanasca Ghauri (new synonym) and Asymmetrasca Dlabola were originally established for two complexes of closely related species from the New and Old Worlds, respectively. Species in both groups agree substantially with the diagnosis of Empoasca given above, differing from E. fabae only in a few details of the male genitalia. Therefore, these two taxa are here treated as synonyms of Empoasca . Although many recent authors, mostly in non-taxonomic papers, have continued to recognize Asymmetrasca as a valid genus, we follow Dworakowska (1971) in treating this taxon as a junior synonym of Empoasca . Most species of Empoasca (sensu stricto) appear to be restricted to the New World. Moderately speciose faunas are also known to occur in tropical Africa and Asia but relatively few species of Empoasca (s.s.) are recorded from the Palaearctic region.