A key to genera of South American Deltocephalini ( Hemiptera : Cicadellidae : Deltocephalinae ) with descriptions of new taxa and nomenclatural changes

A key to genera of South American Deltocephalini Dallas, 1870 based on adult males is presented. Two new genera, each based on a single new species from Argentina are described and illustrated: Corrientesia gen. n. based on type species C. ochrescens sp. n. and Salnogia gen. n. based on type species S. fl etcheri sp. n. A new species of Graminella DeLong, 1936, G. schrocki sp. n. from Argentina is also described and illustrated. Graminella stelliger (Berg, 1884) equals Fusanus acristylus Cheng, 1980, syn. n. A new combination, Limpica pallida (Linnavuori & DeLong, 1979) comb. n., transferred from Reventazonia Linnavuori, 1959, is also proposed. Quaziptus Kramer, 1965, is returned from Paralimnini Distant, 1908 to Deltocephalini Dallas, 1870. ZooBank Article LSID: BBAD822F-F76E-4BD0-89C0-685F3266A27F

but new species continue to be discovered, especially by vacuum sampling in native grasslands (Duan et al., 2016a(Duan et al., , b, 2017a(Duan et al., , b, 2018a, b), b).Although the genus-level classifi cation of Deltocephalini is somewhat unstable and in need of comprehensive revision, most of the recently discovered South American species have been referable to previously described genera.Here we provide a comprehensive key to South American genera of the tribe and describe two new genera to accommodate some species that do not appear to be closely related to previously described genera.We also describe a new Graminella species, propose new generic placements for two previously described species from Brazil and Paraguay, and transfer a genus previously placed in Paralimnini to Deltocephalini.

MATERIAL AND METHODS
The material studied here is deposited in the Museo de La Plata, La Plata, Argentina (MLP) and the Illinois Natural History Survey, Champaign, USA (INHS).Morphological terminology follows Die trich (2005) and Zhang (1990).Digital photographs were taken with a QImaging Micropublisher 3.3 digital camera mounted on an Olympus BX41 stereo microscope and with a Nikon D1x digital SLR camera confi gured with lenses by the Microptics, Digital Lab XLT system.Photographs were modifi ed with Adobe Photoshop CS.

INTRODUCTION
The grass-specialist leafhopper tribe Deltocephalini is a diverse group comprising 70 genera and > 600 species distributed worldwide.Morphological and molecular phylogenetic analyses to date suggest that it is monophyletic and closely related to Paralimnini, but further taxon sampling in these large tribes and more data are needed.The two tribes together appear to be related to Tetartostylini Wagner, 1951 which also possesses the tapered clypellus and linear connective.Many genera and species of Deltocephalini are morphologically quite similar to each other.Revisions of many genera and identifi cation keys, especially of the Neotropical fauna, are needed (Zahniser & Dietrich, 2013).Species of this tribe are abundant in both native grasslands and agroecosystems and include vectors of plant pathogens.The group is distinguished by the linear (not Y-shaped) connective fused to the aedeagus in the male genitalia (Webb & Viraktamath, 2009).The fauna of this tribe in South America is highly diverse.Linnavuori (1959) provided the fi rst key to Neotropical genera of the tribe, including 16 of the genera currently placed in Deltocephalini.Cheng (1980) provided a key to the 10 genera of Deltocephalini recorded from Paraguay.The South American Deltocephalini fauna now comprises 27 genera (17 endemic) and > 150 known endemic species,

Key to South American genera of Deltocephalini (males)
Note: Sanluisia Linnavuori, 1959, known from a single female specimen, is not included.
1 Forewing with two anteapical cells; male macropterous, female usually brachypterous; head, pronotum and mesonotum pale yellow or orange, without dark spots or longitudinal stripes (Fig. 1A-D navuori, 1959navuori, (after Linnavuori, 1959)); K, L -Haldorus (Haldorus) capreolus Linnavuori, 1959(after Linnavuori, 1959); M -Quaziptus chapini (after Kramer, 1965).A, E -apex of forewing; B -apex of male pygofer lobe, lateral view (without macrosetae); C, F -subgenital plate and style; D, H, J, L -aedeagus, lateral view; G, K, M -aedeagus, ventral view; I -male pygofer lobe, lateral view (without macrosetae).Morphology.Body robust, not depressed.Head much wider than pronotum, crown depressed, anterior margin distinctly angulate in dorsal view, slightly shorter than distance between eyes; ocellus small, less than half ocellar diameter from eye.Face moderately convex, length shorter than width; area between lateral frontal suture and eye strongly and evenly narrowed from antennal pit to crown margin, mesal margin of eye entire; frontoclypeus relatively narrow; antenna as long as width of head; clypeal sulcus poorly delimited or absent; anteclypeus tapered at base, but parallel sided through most of length, apex even with ventral margin of gena; lorum semicircular, narrower than anteclypeus, well separated from lateral margin of   face.Pronotum with lateral margin very short, eye nearly touching wing base.Forewing submacropterous in both sexes, apex obliquely truncate, appendix very narrow, vein R1 strongly refl exed, four closed anteapical cells present (central anteapical cell divided by crossvein), one or more supernumerary crossveins present in clavus and sometimes in corium.Front femur row AV with ~ 7 short, stout setae in basal half; row IC with ~ 6 fi ne pale setae.Front tibia dorsal macrosetae 1 + 4. Hind femur macrosetal formula 2 + 2 + 1. Hind tibial rows PD, AD and AV with ca. 8, 9 and 12 macrosetae, respectively; PD with one seta about half as long as macrosetae between successive macrosetae; AD with 1-4 short, stout setae between successive macrosetae.Hind tarsomere I with two well delimited plantar rows of stout, tapered setae; pecten with 4-5 platellae.Male and female abdominal tergite VIII with group of macrosetae near lateral margin.
Male genitalia.Pygofer well sclerotized dorsally in basal half; lobe without processes, with membranous posterodorsal section, and numerous long macrosetae restricted to well-sclerotized section of distal half.Segment X short and weakly sclerotized, without processes.Valve subtriangular, wider than long, posterior margin bluntly angulate.Subgenital plate triangular, apex sharply pointed, macrosetae arranged in uniseriate lateral row.Style with articulating arm short; preapical lobe distinct, angulate; apophysis moderately long and stout, digitiform.Connective shorter than aedeagus with arms slightly bowed laterad near midlength.Aedeagus with dorsal apodeme slender, platelike in posterior view; shaft slender, tubular, with pair of asymmetric apical processes; gonopore small but well delimited, preapical on ventral surface.
Female.Sternite VII with posterior margin broadly and shallowly concave (Fig. 21E).First valvula dorsal sculpturing imbricate, continuous with granulose ventral sculptured area near apex (Fig. 21A, B).Second valvula nearly uniform in width through most of length, dorsal margin with sclerotized tooth in middle of unpigmented area near midlength, distal toothed section occupying less than half total length, with several evenly spaced conical teeth each separated by 2-5 smaller teeth, apex somewhat attenuated (Fig. 21C-D).
Etymology.The genus name is based on that of the Argentine province from which the only known specimens were collected; gender feminine.

Distribution. Argentina.
Remarks.This genus is similar to the mostly North American genus Polyamia in having the forewing submacropterous with extra crossveins but differs in having the pygofer lobe with a poorly sclerotized posterodorsal section and the aedeagus with pair of long apical processes.Some species of the South American genus Loreta also have long, paired apical processes on the aedeagus, but the wings are fully developed, the aedeagal shaft is strongly depressed and straplike, and the forewing lacks supernumerary crossveins (Duan et al., 2016b).A group of macrosetae near the lateral margin of abdominal tergite VIII also occurs in Cortona but only in the female.1979(after Linnavuori & DeLong, 1979a); E-G -Spathifer fuscatus Linnavuori, 1955(after Linnavuori, 1959).A, C -aedeagus, ventral view; B -aedeagus, lateral view; D, G -connective and aedeagus, lateral view; E -connective and aedeagus, ventral view; F -apex of aedeagus, ventral view.
Male genitalia.Pygofer lobe with membranous posterodorsal area forming convex area in sclerotized section distally, caudal margin truncate (Fig. 20A, B).Subgenital plate lateral margin weakly concave (Fig. 20C).Style preapical lobe rectangular; apophysis slightly laterally curved (Fig. 20D).Aedeagus with atrium enlarged, ventral margin semicircular in lateral view; shaft evenly curved dorsad in lateral view, with 2-4 short asymmetrically arranged teeth on each side basad of gonopore; distal processes extended basolaterad, slightly less than half length of shaft (Fig. 20E, F).    sal view, shorter than distance between eyes; ocellus small, separated from eye by slightly more than one ocellar diameter.Face relatively fl at, width greater than length; area between lateral frontal suture and eye slightly narrowed from antennal pit to crown margin, mesal margin of eye strongly emarginate adjacent to antennal base; antenna shorter than head width; frontoclypeus broad, weakly convex; clypeal sulcus prominent; anteclypeus tapering, extending to lower margin of genae; lorum semicircular, narrower than anteclypeus, well separated from lateral margin of face.Pronotum with lateral margin relatively long, eye well separated from wing base.Forewing fully developed, without extra crossveins, apex rounded, appendix narrow, R1 and R2 + 3 not refl exed, three anteapical cells present, inner cell closed or open basally, central cell rarely divided.Front femur row AV with several short, stout setae in basal half,   somewhat irregularly arranged; row IC with ~8 fi ne setae.Front tibia dorsal macrosetae 3 + 4. Hind femur macrosetal formula 2 + 1 + 1. Hind tibial rows PD, AD and AV with ca. 9, 10 and 11 macrosetae, respectively; PD with seta about half as long as macrosetae between successive macrosetae; AD with 1-4 short, stout setae between successive macrosetae.Hind tarsomere I with two well delimited plantar rows of stout, tapered setae; pecten with 4-5 platellae.
Etymology.The generic name is an arbitrary combination of letters; gender feminine.
Etymology.This species is named for Dr. M.J. Fletcher who has made outstanding contributions to leafhopper classifi cation.Distribution.North and South America, China.

Distribution. Argentina.
Remarks.Until now, Graminella comprised 29 species including ten recorded from South America (Blocker et al., 1995).Below we describe a new species from Argentina, and propose a new synonymy for two other South American taxa belonging to this genus.Length.Male: 3.7 mm (female unknown).Description.Coloration.Dorsum with pair of orange longitudinal submedial bands extended from apex of crown to forewing clavus, coronal suture light brown.Pronotum lateral pair of longitudinal bands extended across mesonotum to clavus (Fig. 25A).Forewing membrane opaquely sclerotized orange brown in basal half, veins white, distal part of wing pale translucent (Fig. 25A, B).Face mostly pale yellow (Fig. 25C).Venter of thorax and legs pale yellow, unmarked (Fig. 25B, C).
Etymology.This species is named for Dr. J.R. Schrock who has helped the senior author revise many manuscripts.

Distribution. Argentina.
Remarks.This species is somewhat similar to the North American species Graminella fl oridana DeLong & Mohr, 1937 in coloration and the structure of the genitalia but differs in lacking dark spots on the anterior margin of the crown, having three pairs of longitudinal stripes on the pronotum, and in having the base of the aedeagus rounded and forming a continuous curve with the connective rather than sharply angulate ventrally in lateral view.

Graminella stelliger (Berg, 1884)
Athysanus stelliger Berg, 1884: 29.Fusanus acristylus Cheng, 1980: 79, syn. n.Remarks.Cheng's (1980) description and illustrations of F. acristylus indicate that this taxon is a synonym of G. stelliger, which was re-described and illustrated by Lin-  navuori (1959).The apex of the aedeagus of this species varies somwhat in shape intraspecifi cally.The similarity of F. acristylus to Fusanus griseostriatus Linnavuori, 1955, noted by Cheng (1980) is superfi cial because the style of the former has a strongly and acutely produced preapical lobe, a feature characteristic of most Graminella species, including G. stelliger.Species of Fusanus have the style preapical lobe rounded.
Limpica pallida (Linnavuori & DeLong, 1979), comb.n.Linnavuori & DeLong, 1979: 49.Remarks.Limpica was originally established based on a single species, Limpica forcata Cheng, 1980, from Paraguay.Comparison of Cheng's (1980) original description and illustrations of the type species of the genus with those of Linnavuori & DeLong's (1979) species clearly indicates that the two species are closely related.Species of Reventazonia have the gonopore situated on the ventral side of the shaft apex and extended basad, but the shaft apex is only slightly notched, not deeply divided as in Limpica.Based on the original descriptions and illustrations, L. pallida and L. forcata are identical in size and very similar in coloration but the latter differs in having the distal lobes of the aedeagus more slender and the subgenital plate with fewer macrosetae.The type specimens of both species need to be compared to determine whether the two taxa should continue to be treated as separate species.

Reventazonia pallida
Genus Quaziptus Kramer, 1965, reinstated tribal placement Quaziptus Kramer, 1965: 29.Type species: Quaziptus chapini Kramer, 1965.Remarks.This monotypic genus was originally unplaced to tribe within Deltocephalinae but Oman et al. (1990) listed it as belonging to Deltocephalini.Kamitani (1999) transferred the genus to Paralimnini and this placement was followed by Zahniser & Dietrich (2013).The type species, Q. chapini, clearly has the connective linear and fused to the aedeagus, so the genus is here returned to Deltocephalini and may be separated from other South American genera by the key given above.Remarks.DeLong (1970) described this genus based on two male specimens of one new species (N.fuegoensis) from southern Chile, placing it in Deltocephalinae, but not indicating a tribal placement.Linnavuori & DeLong (1977) placed the genus in Deltocephalini and described a second species, N. bicornis, also from Chile.Although Linnavuori & DeLong (1977) described N. bicornis as being similar to the type species of Nullamia "in general structure" published illustrations of the male genitalia of both species cast doubt on whether they are congeneric.DeLong's (1970) illustrations of the aedeagus of N. fuegoensis indicate that this species has a simple aedeagus, without processes and with a shallowly emarginate apex, whereas N. bicornis has a pair of long aedeagal processes arising near the midlength of the shaft and extended distad, with the shaft apex entire.As indicated in the above key, these two species will key to Amplicephalus and Haldorus, respectively.Unfortunately, DeLong's (1970) original description and drawings of N. fuegoensis are insuffi cient to establish its relationship to Amplicephalus with confi dence and, although the male genitalia of N. bicornis resemble those of Haldorus, the latter genus has the forewings fully macropterous, rather than shortened as in Nullamia.Thus, further comparative study of both Nullamia species will be necessary to determine the status and relationships of the genus.