Decliviassus, Dai, Wu, Dietrich, Christopher H. & Zhang, Yalin, 2015

Dai, Wu, Dietrich, Christopher H. & Zhang, Yalin, 2015, A review of the leafhopper tribe Hyalojassini (Hemiptera: Cicadellidae: Iassinae) with description of new taxa, Zootaxa 3911 (1), pp. 1-142 : 15-16

Decliviassus gen. nov.

Type species: D. maculatus sp. nov.

Stramineous, with or without small black spots on dorsum of thorax and forewing ( Fig. 2 A–F). Body robust, cylindrical, not or only weakly depressed ( Fig. 2 A–F). Head in dorsal view narrower than pronotum ( Fig. 2 A, C, E); crown not developed, vertex vertical or nearly so, very short or not visible in dorsal view ( Fig. 2 A, C, E); vertex and frontoclypeus transversely rugose; face distinctly broader than tall; gena obtusely emarginate below eye; rostrum slender, extended slightly beyond front trochanter; anteclypeus convex, tapered from base to apex, apex truncate, even with lower margin of gena; lorum narrow, well separated from lateral and ventral margins of gena, with basal fourth of mesal margin bordering frontoclypeus; frontoclypeus convex; antennal ledge well developed, broad, transverse; lateral frontal suture nearly obsolete, extended only short distance above antennal ledge; ocellus large, directly above antennal pit and distant from eye ( Fig. 2 B, D, F). Pronotum strongly convex, nearly vertical anteriorly, transversely rugose; lateral margins long, strongly carinate, evenly divergent posterad ( Fig. 2 A, C, E). Exposed part of mesonotum and scutellum together distinctly shorter than pronotum, transversely rugose; scutellar suture arched anterad, scutellum weakly convex with apex acute ( Fig. 2 A, C, E). Forewing venation moderately well delimited; membrane opaquely sclerotized in basal 2/3, with or without numerous small black spots; setae very short, fine, and inconspicuous; appendix broad, extended to wing apex, slightly narrower than inner apical cell; vein R with 5–7 branches; three closed anteapical cells present; apical cells 1–4 long, parallel-sided, progressively longer toward trailing edge of wing, bases not aligned; posterior branch of CuA connected to margin at apex of clavus; clavus truncate apically; texture of inner apical cell same as that of appendix and adjacent apical cell ( Fig. 2 A–F). Front femur with pair of dorsoapical macrosetae and AM1 well developed but PD, AD and AM without well differentiated preapical setae; intercalary group consisting of irregular double row of moderately stout setae continuous with setae of similar size in basal AV group; PV with several well differentiated macrosetae; tibia with dorsal surface flat and bicarinate, AD and PD each with 7–8 macrosetae. Mesothoracic femur PD with 2 and AD with 6 macrosetae; ventral setae poorly differentiated. Hind femur macrosetae 2+2+1 with antepenultimate seta as large as others; tibial rows PD, AD, and AV with 20, 12, and 15 macrosetae, respectively; tarsomere I without dorsoapical setae, plantar surface bare, pecten with 6 platellae.

Male abdominal apodemes poorly developed. Sternite VIII ca. twice as long as sternite VII, longer than broad, lateral margins tapered posterad, apex convexly produced. Genital capsule with posteroventral part almost completely concealed by sternite VIII in repose, with only anal tube and part of posterior pygofer margin visible. Pygofer with tergite long, well sclerotized, narrowly emarginate distally in dorsal view; lobes elongated, acutely angulate, with posterodorsal group of several macrosetae; posterior setal group undifferentiated, posterior margin long and straight, with short basolateral process bearing two or more lobes ( Figs 10 E, 11C, 12E, 13B); anterodorsal margin in lateral view emarginate along intersegmental membrane; intersegmental membrane between anal tube and aedeagal atrium without accessory lobes, sclerites, or setae; basolateral setal group absent ( Figs 10 A, 12A, 13A). Subgenital plates short, broad, depressed, strongly constricted and close together at base, strongly divergent and broadened distally, with few fine setae ( Figs 10 D, 12F, 13A). Valve long, subquadrate, broadly fused to pygofer at base, posterior margin truncate( Figs 10 D, 12F, 13A). Connective well sclerotized, relatively long, straplike, lateral lobes weakly developed, articulated to anteroventral corner of aedeagal atrium, median anterior lobe extended well ventrad of style ( Figs 10 A, 11A, 12A, 13A, 13F). Style well developed, articulated to connective well below aedeagal atrium, in lateral view with apodeme and apophysis both nearly straight with junction forming obtuse angle; apodeme long, spatulate; apophysis slightly longer than apodeme, apex weakly or not expanded, with preapical tooth or angle ( Figs 10 C, 11B, 12D, 13C). Aedeagus simple, tubular basally, compressed distally, U-shaped in lateral view, preatrium absent, atrium in posterior view without well developed ventrolateral lobes, dorsal apodeme columnlike; shaft with pair of slender processes distad of gonopore extended basolaterad, apex tapered in lateral and posterior views; gonopore preapical on posterior surface with inner surface glabrous ( Figs 10 B, 11B, 12B, 12C, 13D, 13E). Female unknown.

Notes. The genus name combines decliv -, meaning sloping downward, with Iassus , the name of the type genus of Iassinae, and refers to the strongly declivous pronotum and vertex. The genus appears to be closely related to Trocnadella, Siniassus , and Lamelliassus based on the broad forewing appendix and the structure of the male genital capsule, but may be distinugished by the strongly declivous pronotum, elongate, acutely angular pygofer lobe, and the presence of a well developed ventral pygofer appendage.

Figures

FIGURE 2. Dorsal and lateral habitus. A, B, Decliviassus bipunctatus sp. nov.; C, D, Decliviassus maculatus sp. nov.; E, F, Decliviassus nudus sp. nov.; G, H, Kanchanaburiassus maculatus sp. nov.

FIGURE 10. The holotype of Decliviassus bipunctatus sp. nov. A. Genital capsule, lateral view; B. Aedeagus, lateral view; C. Style, lateral view; D. Subgenital plates, ventral view; E. Ventral process of pygofer side, caudolateral view; F. Apex of aedeagus, ventral view.