Nigrojassus Krishnankutty & Dietrich 2012, New Genus
Creators: name: Krishnankutty, Sindhu M.
name: Dietrich, Christopher H.
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Cicadellidae
Nigrojassus

description: Nigrojassus New Genus
Type species: Nigrojassus madhurai sp. nov.
Diagnosis. Nigrojassus resembles Hoplojassus in the dark coloration, dorsolaterally situated ocelli, elongated scutellum, broad forewing appendix extended to the costal margin, absence of forewing crossvein r-m1, separate hind wing R4+5 and M1+2 veins, 2+2+1+1 hind femoral macrosetal formula, and presence of numerous scattered stout setae on the male subgenital plate. Nigrojassus differs in being much smaller overall, with the scutellum shorter and depressed, the male anal tube lacking ventrolateral hooks, and the pygofer with a distinct posterior process.
Description. Medium-sized, robust, darkly pigmented leafhoppers. Head rounded, weakly depressed, without sharp transition between crown and face; without setae or striations. Crown in dorsal view (Figs 1, 6) weakly developed, without spots, slightly longer medially than next to eyes; in profile continuing contour of pronotum and evenly rounded to antennal ledge. Ocelli on anterior margin of crown, situated closer to eyes than to each other. Antennal ledge prominent, oblique; antenna short, length subequal to half width of head. Frontoclypeus slightly longer than broad, evenly convex. Lateral frontal suture conspicuous, extending to antennal pit, continuing dorsad of antennal ledge but not reaching ocellus. Gena moderately broad rounded, weakly emarginate below eye, extending to apical margin of clypellus. Transclypeal suture obsolete. Lorum flat, slightly narrower than clypellus, well separated from genal margin apically, basal half bordering frontoclypeus. Anteclypeus slightly convex medially, parallel sided, apical margin slightly concave. Rostrum slender, parallel sided, extended to apex of front trochanter.
Pronotum (Figs 1, 2, 6, 7) wider than head, moderately declivous anteriorly, with numerous fine transverse striations; lateral margin long, distinctly carinate, evenly divergent posterad in dorsal view. Exposed part of mesonotum and scutellum flat, longer than pronotum, distinctly longer than broad, tapered, with numerous transverse striations, apex extended halfway to apex of clavus of forewing at rest. Forewing (Fig. 4) tectiform, shiny black, basal half opaque, apical part hyaline and amber brown in color; with scattered fine white setae confined to basal half and short stout light brown setae along claval margin; venation conspicuous, crossvein s usually present and well basad of crossvein r-m2, crossveins r-m1, mcu1 and m-cu2 absent (only one closed anteapical cell present); vein R with 3 branches; inner apical as wide as adjacent cell, less than half as long as broad, well delimited by submarginal vein, with same texture as that of other cells; appendix broad, slightly narrower than width of inner apical cell, extending from claval apex to costal margin, pointed near M1+2. Hindwing (Fig. 5) with submarginal vein not extending to jugum, R4+5 and M1+2 separate connected by crossvein; costal margin strongly arcuate near base. Legs shiny black. Front femur with dorsoapical pair of setae; AM1 undifferentiated; intercalary, AV, and PV groups undifferentiated, with scattered setae; tibia slender, dorsal surface narrowly bicarinate, with pair of apical macrosetae, ventral surface with scattered macrosetae. Middle femur with pair of dorsoapical macrosetae and few ventral macrosetae; tibia resembling that of front leg. Hind femur setal formula 2+2+1+1, penultimate setal pair close-set with posterior seta half length of anterior seta. Hind tibia flattened, with series of stout setae interspersed with hair-like setae, setal rows PD, AD, and AV with 13, 9, and 9 macrosetae, respectively; setal bases of AV row enlarged but not spinelike; PV row with ~20 fine setae basad of and interspersed among, preapical macrosetae; tarsomere I without stout dorsoapical pair of macrosetae, row AV double, PV single, pecten with four platellae; tarsomere II with 2 platellae.
Male abdomen. 3S apodemes short, not extending posterad past segment III. Sternite VIII slightly produced posteriorly, longer than sternite VII, only partially concealing subgenital plates in repose. Pygofer with tergite well developed with short, narrow posteromedial emargination flanked by small paired lobes (Fig. 10) bearing stout setae; sides in lateral view (Fig. 9) almost parallel sided, with posterior margin dorsal half slightly convex medially, with posterior process arising near midheight; ventrolateral lobe with group of short, stout setae. Anal tube well sclerotized, appendage absent. Valve (Fig. 11) triangular, fused to pygofer at base. Subgenital plates (Fig.12) freely articulated to valve and separated from each other; flattened and depressed basally, somewhat compressed distally, with macrosetae evenly distributed over ventral surface and fine short setae along outer margin near apex. Connective (Fig.16) well sclerotized, median anterior lobe long and slender, lateral arms short, apex weakly bilobed, articulated to aedeagus. Style in lateral view (Fig. 15) with apodeme long and nearly straight; apophysis sinuate basally, curved dorsolaterad distally, slightly expanded beyond midlength, tapered to apex; ventral margin with angulate prominence beyond midlength, Aedeagus (Figs 17, 18) articulated with connective, preatrium absent; dorsal apodeme well developed, columnlike; shaft curved dorsad with or without processes, atrium well developed almost as half of shaft; gonopore posteroapical. Conjunctiva between dorsal apodeme of aedeagus and base of anal tube distinctly sclerotized and forming distinct dorsal connective (Fig. 13) with ventral plate and long, paired dorsolateral arms.
Female. Unknown.
Etymology. The genus name, a masculine noun, was formed by appending nigro - (black), referring to the black coloration of species in the genus, to jassus, a stem commonly used in forming leafhopper genus names. Notes. Nigrojassus gen. nov. is similar to Hoplojassus in having the following features: body robust; head evenly convex with ocelli situated dorsolaterally on face near eyes; scutellum longer than pronotum; forewing without crossvein r-m1, appendix broad and extended around wing apex; hindwing R4+5 and M1+2 separate and connected by crossvein, hind femur with 2+2+1+1 macrosetal arrangement; male subgenital plate with numerous scattered macrosetae.
The new genus can be separated from Hoplojassus based on the following combination of characters: body size much smaller; ocelli near anterior margin of crown; scutellum not surpassing apex of clavus of forewing at rest, not keeled along posterior half; male anal tube without basolateral hook, pygofer with process.
Hoplojassus and Nigrojassus appear to represent a distinct lineage, separate from other New World Iassinae (sensu Blocker). As noted by Dietrich (1993) Hoplojassus retains a number of features thought to be plesiomorphic for the group as a whole. These include the separate R4+5 and M1+2 veins in the hind wing; the elongate, sigmoid style; the partially retracted male genital capsule; the large subgenital plates; and the simple connective with a well developed anterior lobe. Such features are shared by the new genus. In contrast, most New World iassines have a number of highly derived morphological features, including fusion of veins R4+5 and M1+ 2 in the hind wing, partial or complete loss of the forewing vein separating the inner apical cell from the appendix, and modification of the male genital capsule such that the subgenital plates are reduced and completely concealed by the enlarged pregenital sternite, the connective and styles are also highly modified.
description: Published as part of Krishnankutty, Sindhu M. & Dietrich, Christopher H., 2012, Two new iassine leafhopper genera from Ecuador (Hemiptera: Cicadellidae), pp. 43-50 in Zootaxa 3530 on pages 44-47, DOI: 10.5281/zenodo.282780