A new genus , Smilirhexia , of Smiliini ( Hemiptera , Membracidae ) from Costa Rica

Smilirhexia naranja, gen. n. and sp. n., is described from Central America, the southern limit of the tribe Smiliini, and represents a strong divergence from the morphology of the oak-feeding genera prevalent in North America.


Introduction
Th e tribe Smiliini is the nominotypical tribe of Smiliinae, one of the largest subfamilies of treehoppers (McKamey 1998).Th e subfamily is native to the New World, being most speciose in the tropics.In contrast to this subfamilial pattern, the species of Smiliini are primarily North American, with the great majority of species oligophagous on oaks (Quercus spp., Fagaceae) and the southernmost species recorded from Panama (R. Cocroft, pers. comm.).Excluding the odd smiliine genus Antianthe Fowler, the tribe's southern limit is even more restricted than that of oaks, which extend southward to Colombia.
Th e mostly recently described species is Telamona archiboldi Froeschner (1968), from Florida.Th ere have been only three recent taxonomic works on Smiliini (McKamey and Deitz 1991, Wood and Pesek 1992, Wallace and Deitz 2003).Th e other recent papers consist of local or regional checklists (Kopp andYonke 1973, 1974;Johnson and Freytag 1997;Wallace et al. 2003;Flynn et al. 2003;Wallace and Troyano 2006).Quisenberry et al. (1978) described the immatures of most genera of Smiliini.
Diagnosis.Th e new genus diff ers from all other genera of the tribe in having a smooth and shining pronotum, which is broad, almost completely convex, and brightly colored.Description of male.Head (Fig. 3) glabrous, subtriangular in anterior view, ocelli equidistant from each other and from eyes.Pronotum (Figs 1-3) entirely concealing scutellum, convex, dorsal carina elevated only in posterior half, and weakly, otherwise delineated by absence of punctures; surface shining, punctures shallow and lacking setae; humeral angles not projected laterally beyond wing bases; posterior pronotal process ending at apex of forewing cell M 3+4 (last apical cell).Forewing (Fig. 1) free, in repose not concealed wholly or in part by pronotum; without r-m crossveins, with veins R and M adjacent basally, weakly divergent soon after, R 4+5 and M 1+2 confl uent for a short distance before apex, and strongly divergent at wing apex; R 2+3 present as distinct branch of R; R 4 and R 5 separately joined to vein M, creating a small cell R 4 near center of wing.Hind wing with short r-m crossvein (holotype right wing) or veins R and M fused at single point (holotype left wing).Femora, tibiae, and tarsomeres lacking cucullate setae except metathoracic femur with two apically, metathoracic tibia with three rows (row 2 double), and metathoracic tarsomere I with 4 cucullate setae at apex.Metathoracic coxa and trochanter without apposed processes.Abdomen lacking fenestrae or mid-dorsal protuberances.
Female.Unknown.Distribution.Costa Rica, Puntarenas Prov.Material Examined.Holotype male of Smilirhexia naranja, sp.n.Etymology.Th e new genus name is feminine and combines the name of its apparent tribe and the name of an unrelated genus, Rhexia Stål, which it resembles superficially [e.g., Rhexia viridicollis (Fowler), illustrated by Deitz (1983)].
Discussion.Th e distally confl uent radial and medial veins, which diverge before the forewing apex, and the lack of processes on the metathoracic coxa and trochanter place the new genus fi rmly in the subfamily Smiliinae.In Deitz's key to the higher classifi cation, the genus keys to the tribe Smiliini due to the presence of 2 m-cu crossveins.Th e only discrepancy is that in the new genus, the forewing is completely exposed rather than partially concealed.Most genera of the tribe are morphologically similar and authentic records of only a few species exist for Central America, the tribe's southern limit.Th e notable exception is the genus Antianthe Fowler, which is laterally compressed, strongly crested, and with pronounced humeral angles, and which occurs from the southern USA to South America.Smilirhexia appears to represent another distinct morphological form for Smiliini that may help to elucidate the evolutionary origin of this tribe.
Species of the subfamily Darninae, which appears to be a close relative of Smiliinae, also have the forewing with two r-m crossveins, as in Smiliini.Interestingly, Cymbomorpha Stål (Cymbomorphini, Darninae) occasionally have the characteristic forewing venation of Smiliinae, with veins R and M confl uent for a short distance before the apex, and double setation in metathoracic tibial row II.Both Cymbomorpha and Eumela Stål, the other cymbomorphine genus, and Smilidarnis Andrade, 1989 (a Neotropical, unplaced genus with characters of both Darninae -especially Cymbomorphini -and Smiliinae), exhibit the shining pronotal surface and completely exposed forewings of the new genus Smilirhexia.long, lacking protuberances.Aedeagus narrow in anterior view, in lateral view Ushaped and widest at mid-length, anterior margin with many denticulae of increasing size ventrally; styles simple, distally recurved (Fig. 4 Etymology.Th e species epithet is a Spanish adjective for orange, the predominant pronotal color of the species.

Smilirhexia naranja
Notes.In Costa Rica, most oaks occur in submontane and montane forests (1500-3200m) (Kappelle et al. 1992).In the Cordillera de Talamanca, which contains the type locality, there are at least eight oak species, with at least three reported from Coto Brus itself: Quercus seemannii Liebm., Q. oocarpa Liebm., and Q. rapurahuensis Pittier ex Trel.(Giddy 2008), and another (Q.insignis M. Martens & Gal.) at 1300m on the trail to Las Alturas (Instituto Nacional de Biodiversidad 2008).In short, it is easily possible that this new treehopper genus, like others in the tribe, feeds on Quercus.