Metaurus Stål, 1866

Song, Zhi-Shun & Liang, Ai-Ping, 2012, Taxonomic revision of the Oriental genus Metaurus Stål (Hemiptera: Fulgoromorpha: Dictyopharidae), with description of a new species, Journal of Natural History 46 (41 - 42), pp. 2563-2575 : 2564-2570

Genus Metaurus Stål, 1866

Metaurus Stål, 1866a: 151 . Type species: Metaurus reticulatus Stål, 1866 ; by subsequent designation.

Metaurus Stål : Stål, 1866b: 391; Atkinson, 1886: 24; Melichar, 1912: 46; Metcalf, 1946: 38.

Diagnosis

Head in front of eyes strongly upturned, produced in a distinctly slender, straight process; vertex with median carina weakly ridged at base and lateral carinae abruptly constricted before eyes into a straight sulcate process; frons with median carina present but indistinct, sometimes absent in apical part, intermediate carinae before eyes slightly converging posteriorly and approaching to frontoclypeal suture; pronotum with median carina sharp and complete, intermediate carinae indistinct; mesonotum tricarinate, lateral carinae incurved anteriorly towards median carina; forewings hyaline, anterior margin distinctly expanded into a narrow, sclerotized costal area; M vein first branching to M 1+2 and M 3+4 veins near basal one-third, and then branching to dozens of accessory veins on apical two-thirds; numerous netted transverse veins among Sc+R, M and CuA veins on apical two-thirds; stigmal area distinctly elongate, with eight or nine cells; legs moderately elongate, fore femora more or less flattened and dilated, with a distinct spine near apex; hind tibiae with seven apical black-tipped spines; segment X (anal tube) of males distinctly broad, basal and apical ventral margins protruded ventrally; aedeagus with a pair of branched endosomal processes extended from phallotheca.

Description

Head ( Figures 1 ; 2 A–C; 4A–C) in front of eyes strongly upturned, produced in a distinctly slender, straight process. Vertex ( Figures 1 A–E; 2A; 4A) basally flat, nearly square; lateral carinae strongly ridged, abruptly constricted before eyes, curved upwardly into a straight sulcate process; posterior margin ridged and angularly concave at about 120 ◦; median carina weakly ridged at base. Frons ( Figures 2C ; 4C ) elongate and broad, but anterior portion with intermediate carinae distinctly narrowed and protruded anteriorly and upwardly in ventral and lateral views ( Figures 2B,C ; 4B,C ), so apical part of frons distinctly visible in dorsal view ( Figures 2A ; 4A ); lateral carinae ridged, distinctly expanded outwards below antennae; posterior margin concave deeply; median carina present but indistinct, sometimes absent in apical part; intermediate carinae before eyes slightly converging posteriorly and approaching to frontoclypeal suture. Postclypeus and anteclypeus strongly convex at middle, with distinct median carina. Rostrum long, reaching to abdominal sternite VI. Genae beyond the eyes strongly arched outwards, thence converging acuminately, so part of genae clearly visible in dorsal view ( Figures 2A ; 4A ). Eyes oval and large. Ocelli relatively large, reddish. Antennae with very small scape; pedicel large and subglobose, with more than 50 distinct sensory plaque organs distributed over entire surface; flagellum long, setuliform.

Pronotum ( Figures 1 A–E; 2A; 4A) distinctly shorter than mesonotum medially, narrow anteriorly, broad posteriorly; anterior margin centrally slightly convex, lateral marginal areas straight and sloping with two longitudinal lateral carinae on each side between eyes and tegulae, lower lateral carina indistinct; posterior margin broadly concave at about 120 ◦; median carina sharp and high, with a big lateral pit on each side, intermediate carinae indistinct. Mesonotum ( Figures 1 A–E; 2A; 4A) tricarinate, lateral carinae incurved anteriorly towards median carina. Forewings ( Figures 1 A–I; 3A) hyaline, much longer than tail of abdomen, nearly three times as long as broad; anterior margin distinctly expanded into a narrow, sclerotized costal area; costal cell without transverse veins, Sc+R forked apicad of claval veins junction; M vein first branching to M 1+2 and M 3+4 veins near basal one-third, and then branching to dozens of accessory veins on apical two-thirds; numerous netted transverse veins among Sc+R, M and CuA veins on apical two-thirds; apical cells 22–24; Pcu and A 1 veins fused into a short Pcu+A 1 vein at apical one-third of clavus; stigmal area distinctly elongate, with eight or nine cells. Hindwings ( Figures 1A ; 3B ) hyaline, CuA vein first branching to CuA 1 and CuA 2 veins near middle, M and CuA 1 veins branching to several accessory on apical two-thirds, with several transverse veins; apical cells 12–14. Legs moderately elongate, fore femora more or less flattened and dilated, with a distinct spine near apex; hind tibiae with seven lateral black-tipped spines and seven apical black-tipped spines; hind tarsomeres I with 15–18 and tarsomeres II with 13–16 black-tipped apical spines.

Male genitalia. Pygofer distinctly wider ventrally than dorsally, dorsal margin slightly excavated to accommodate segment X. Segment X (anal tube) distinctly broad, basal and apical ventral margins protruded ventrally; apical dorsal margin slightly excavated in dorsal view ( Figures 2G ; 4G ) to accommodate anal style; anal style short and small. Gonostyles symmetrical, nearly constant breadth in lateral view ( Figures 2F ; 4F ); upper margin with a dorsally directed, black-tipped process at apex, outer upper edge with a ventrally directed, hook-like process near middle. Aedeagus with a pair of branched endosomal processes from phallotheca: the lower paired branches elongate and inflated, directed laterally, apex subacute and sclerotized; the middle ones short and small, directed inwards; the apical ones elongate, directed posteriorly. Phallobase basally sclerotized and pigmented, with paired membranous inflated apical lobes, without spines ( Figures 2 H–J; 4H–J).

Female genitalia. Segment X (anal tube) relatively small, broadest in middle, gradually narrowed towards apex in dorsal view ( Figure 3C ). Gonocoxae VIII ( Figure 3D ) with two endogonocoxal processes (GxP) membranous and flattened on endogonocoxal lobe (GxL): Gxp1 large and elongate, with a long sclerotized plate in it; Gxp2 smaller, without sclerotized plate. Gonapophyses VIII (first valvulae, Figure 3D ) with anterior connective lamina (ACL) large and sclerotized, with six teeth of varying sizes and shapes in lateral view ( Figure 3D ). Gonapophyses IX (second valvulae, Figure 3E ) with posterior connective lamina (PCL) triangular, symmetrical in ventral view ( Figure 3E ), fused with the intergonocoxal plate (iGxp) at base; iGxp extended cephalad into the genital cavity forming the wall of the gonospiculum. Gonoplacs (third valvulae, Figure 3F ) with three lobes: Gp1 and Gp2 homologous and fused basally; the lateral lobe (Gp1) large and moderately sclerotized, with four long setae at apex; the posterior lobe (Gp2) membranous, in which a long sclerotized plate is visible; the third process (Gp3) very small and membranous, sheltering behind Gp2.

Remarks

The genus Metaurus is externally similar to Igava Melichar, 1912 from South America for the head before eyes strongly upturned, produced in a distinctly slender, straight process. But Igava belongs to the tribe Lappidini Emeljanov for its Sc+R and M veins with a long common stem in the forewings ( Emeljanov 2011).

Metaurus is similar to the Oriental genus Dictyopharina Melichar, 1903 in the tribe Orthopagini , but can be distinguished from the latter by the head in front of eyes strongly upturned, produced in a distinctly slender, straight process; the vertex with median carina only weakly ridged at base (median carina distinct and complete in Dictyopharina ); the anterior margin of the forewings with narrow, sclerotized costal area; the hind tibiae with seven apical spines (eight in Dictyopharina ); the aedeagus with a pair of branched endosomal processes; and the gonoplacs with a small third lobe ( Song and Liang 2006).

In the genus Metaurus , the anterior margin of the forewings is distinctly expanded into a narrow, sclerotized costal area between Costa vein and anterior margin. This character is not present in other Oriental dictyopharid genera, but often exists in Tropiduchidae . M vein is first forked to M 1+2 and M 3+4 veins before CuA near basal one-third of corium, which is branched in succession to dozens of accessory veins on apical two-thirds of corium. There are numerous netted transverse veins among Sc+R, M and CuA veins on apical two-thirds of corium. The aedeagus possesses a pair of branched endosomal processes and the gonoplacs possess a small third lobe. The above characters may represent a series of autapomorphies in Metaurus , or may even represent a new tribe in Dictyopharinae .

Distribution

Oriental Region ( Cambodia; Laos; southwestern China; Thailand).

Key to the species of the genus Metaurus Stål

1. Cephalic process in front of eyes distinctly longer than length from curved point to posterior margin of eyes, with the ratio about 1.4: 1 in lateral view................................................................ M. indet. sp. Cephalic process in front of eyes a little shorter or as long as length from curved point to posterior margin of eyes in lateral view................... 2

2. Cephalic process in front of eyes a little shorter than length from curved point to posterior margin of eyes, with the ratio about 0.7–0.8: 1 in lateral view; segment X of males distinctly short and small, with ratio of the longest length to width near base about 1.1: 1 in dorsal view, apical ventral margins protruded ventrally into a short small process in lateral view; aedeagus with ventral outer apical lobes curved anteriorly in ventral view.......... M. ramusitis sp. nov. Cephalic process in front of eyes as long as length from curved point to posterior margin of eyes in lateral view; segment X of males distinctly large and elongate, with ratio of the longest length to width near base about 1.6: 1 in dorsal view, apical ventral margins protruded ventrally into a large rounded process in lateral view; aedeagus with ventral outer apical lobes directed posteriorly in ventral view...................... M. reticulatus Stål

Figures

Figure 1. Habitus of Metaurus species (A–E, dorsal view; F–I, lateral view). (A) Metaurus reticulatus Stål, holotype, female; (B,F) Metaurus ramusitis sp. nov., holotype, male; (C,G) Metaurus ramusitis sp. nov., paratype, female; (D,H) Metaurus reticulatus Stål, non-type, male; (I) Metaurus indet. sp.

Figure 2. Metaurus ramusitis sp. nov. (A) Head, pronotum and mesonotum, dorsal view; (B) head and pronotum, lateral view; (C) head, ventral view; (D) pygofer and gonostyles, ventral view; (E) pygofer, gonostyles and segment X, lateral view; (F) gonostyles, lateral view; (G) segment X of male, dorsal view; (H) aedeagus, dorsal view; (I) aedeagus, lateral view; (J) aedeagus, ventral view.

Figure 3. Metaurus ramusitis sp. nov. (A) Forewing; (B) hindwing; (C) segment X of female, dorsal view; (D) gonopophysis VIII, dorsolateral view; (E) gonopophysis IX, ventral view; (F) gonoplacs, ventrolateral view.

Figure 4. Metaurus reticulatus Stål. (A) Head, pronotum and mesonotum, dorsal view; (B) head and pronotum, lateral view; (C) head, ventral view; (D) pygofer and gonostyles, ventral view; (E) pygofer, gonostyles and segment X, lateral view; (F) gonostyles, lateral view; (G) segment X of male, dorsal view; (H) aedeagus, dorsal view; (I) aedeagus, lateral view; (J) aedeagus, ventral view.