Tarehylava, Stroiński, 2021

Stroiński, Adam, 2021, Tarehylava, a new planthopper genus from Madagascar (Hemiptera: Fulgoromorpha: Ricaniidae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1), pp. 329-340 : 330-336

Tarehylava gen. nov.

( Figs 1–7 , 11–63 )

Type species. Tarehylava avymaina sp. nov. (here designated).

Diagnosis. Tarehylava gen. nov. differs from all other known Madagascan genera of Ricaniidae by the following characters: vertex arrowhead-shaped, frons elongate, lateral carinae of frons connected with median carina below upper margin and forming extension; lateral lobes of pronotum with transverse carina; tegmen divided in two parts, venation of posterior part swelling and flattened, with setae and sensory structures; costal margin of hind wing without precostal cell.

Description. Head with compound eyes (in dorsal view) slightly narrower than thorax. Vertex ( Figs 2–3 , 11–13 ) distinctly wider at the level of posterior angles than long at midline, arrowhead-shaped, posterior angles placed about the level of midlength of compound eyes; median portion of posterior margin placed before anterior margin of compound eyes; posterior margin strongly elevated medially. Disc of vertex with keel-shape median carina. Frons ( Figs 1, 4 , 15–19 ) with all margins well carinated; frons at upper margin distinctly shorter than high at midline, widest at the lower part; lateral margins covering base of pedicel, incised at the level of ocelli. Frontal disc tricarinate, lateral carinae connected with median carina below upper margin of frons and forming extension; area between connection of frontal carinae and upper margin distinctly swollen; all carinae distinctly surpassing half of disc; median carina straight, lateral carinae in a form of horseshoe almost reaching fronto-clypeal suture, lateral carinae of same length or slightly shorter than median carina, all carinae around point of their connection distinctly elevated, keel-shaped. Disc of frons strongly wrinkled. Compound eyes with a very small callus at postero-ventral margin, elongate in dorsal view. Ocelli present. Antenna ( Figs 22–24 ): pedicel barrel-shaped with a slightly wider tip, with functional area (trichoid sensilla type 1 and antennal plate organs) reaching half of segment length on the dorsal and ventral surfaces, small on the lateral surface; plate organs of crenellated type, surrounded by a ring of elevated spines. Clypeus ( Figs 4 , 15 , 20 ) distinctly narrower than frons, with median carina well visible in lower part. Rostrum with apical segment slightly shorter than subapical one, reaching hind coxae.

Thorax. Pronotum ( Figs 1–3 , 11–13 ) distinctly longer than vertex at midline; disc of pronotum with elevated median carina and two lateral impressions; lateral lobes of pronotum with fully developed postocular transverse carinae, reaching both margins; anterior margin of pronotum placed before the line of anterior margin of compound eyes. Mesonotum ( Figs 1–3 , 11 , 30 ) about as long as combined length of vertex and pronotum at midline and wider in lateral angles than long at midline; disc of mesonotum tricarinate with median carina and lateral carinae present; antero-lateral carinae absent; median carina and lateral carinae separated basally, subparallel; median carina reaching scutellum, lateral carinae reaching posterior margin; lateral angles placed before midlength. Hind legs ( Figs 25–28 ). Metatibia distinctly longer than metafemur, not widened at distal part; metatibia in basal half with two remnants of lateral spines weakly visible in some specimens, two well-developed lateral spines placed distally to each other in distal half, and apical row of well-developed teeth (2+5, 7), different in size and forming irregular line; lateral spines of equal size, larger than internal. Metatarsus with basitarsomere about as long as cumulative length of second and third tarsomeres, with asymmetrical V-shaped row of 9–10 teeth: two lateral teeth different in size, external lateral spine larger than internal lateral one which is similar in size to intermediary spines; each internal tooth bearing strong seta; mesotarsomere with pad of strong setae on ventral side.

Tegmina ( Figs 1–2, 6 , 29–40 ) elongate, semi-convex in basal part, partly coriaceous basally to the level of clavus apex, posterior part of tegmen from the level of clavus apex membranous, partially flexible; tegmina with distinct venation and transverse veinlets, venation of posterior part swelling and flattened, with setae and sensory structures. Costal margin arcuate, apical angle broadly rounded, posterior margin tapered with rounded tip ( Fig. 5 ); tornus (postclaval margin) present and weakly concave. Costal area with dense transverse veinlets, ending at the level of clavus apex; very narrow basally (to 1/3 of length), distinctly wider (also wider than costal cell) more posteriorly. Costal cell with irregular net of transverse veinlets in basal part. Basal cell elongate, narrow, distinctly longer than wide (about 3 times). Longitudinal veins ScP+RA, MP and CuA leaving basal cell separated; all first forks of longitudinal veins placed distinctly before half of tegmen; veins ScRA and RP arising as long common stem from basal cell; first fork placed before first fork of MP; first fork of MP placed before or almost at claval connection (never extending beyond this level); Cu stem always longer than MP stem with first fork at the level of claval connection or more posteriorly. Nodal line absent. Cubital cell with transverse veinlets (weakly visible in some specimens). Clavus closed; CuP ending at margin, claval veins (Pcu and A1) fused distinctly after midlength of CuP; posterocubital cell (basal and posterior parts), postcubital and anal cells with transverse veinlets, transverse veinlets of postcubital and anal cells weakly visible in some specimens.

Hind wing ( Fig. 7 ) shorter than tegmina, with posteri- or margin reaching midlength of the area between tip of clavus and posterior margin of tegmina; anterior margin without precostal cell; ScRA and MP forking distinctly after midlength of wing in distal part, first fork of MP slightly more distad than ScRA but both close each other, CuA forking approximately at wing midlength; ScRA with single terminal, RP with 2–3, MP with 3–4, CuA with 6–7 terminals; rp-m, m-cua (1–2) and icu (1–4, variable character) transverse veinlets present in distal part of wing.

Female terminalia ( Figs 41–63 ). Pregenital sternite ( Figs 46–48 , 54, 58 ) with well-developed, elongate-oval and distinctly separated lateral lobes; median part of pregenital sternite narrow, anterior and posterior margins almost straight medially; posterior margin without any process. Anal tube in lateral view ( Figs 41–42 , 55, 57 ), elongate, not extending beyond the midlength of upper margin of gonoplac; basal part of anal tube distinctly wider than posterior one; anal opening, in dorsal and lateral views, placed before midlenght; anal tube, in dorsal view ( Figs 44–45 , 53 ), elongate ovoid, wider at midlenght; anal style (paraproct) and anal segment (epiproct) short, not extending beyond posterior margin of anal tube. Gonoplac ( Figs 41–43, 46 , 49–52 , 55, 59 ) well developed, unilobate, laterally flattened; posterior margin of the gonoplac with single row of well-developed teeth placed alongside apical part of dorsal margin and upper half of posterior margin; membranous parts of gonoplac in two parts: first part narrow, weakly sclerotized, placed on lower part of posterior margin below teeth, second part large, fully membranous, placed ventro-basad of the gonoplac. Gonapophysis VIII ( Fig. 60 ) elongate, sabre-like, V-shaped in cross section, with teeth at posterior part of dorsal margin; endogonocoxal process tapering apicad, slightly shorter than gonapophysis VIII, with median sclerotized belt surrounded by membranous part. Gonapophyses IX and gonospiculum bridge well developed as in Figs 61–62 . Bursa copulatrix with two pouches connected with short ductus; first pouch elongate, with cells and sclerotized ornamentation (except dorsal part), with sclerotized plate with very large median sclerite and 5–8 small petals around; second pouch elonga- te-oval, smaller than first one, without cell but with sclerotized plates. Spermatheca ( Fig. 63 ) well-developed; ductus receptaculi elongate and narrow, ribbed; diverticulum ductus with two parts (about the same length), distinctly longer (about twice) than ductus receptaculi, with long, narrow, smooth basal ductus, and long, smooth, wider apical ductus.

Male. Unknown.

Etymology. The generic name Tarehylava is a combination of two Malagasy words: “tarehy” (= face) and “lava” (= long), which refers to the characteristic prolongation of the frons. Gender feminine.

Distribution. South-western Madagascar: Atsimo-Andrefana region ( Figs 8–10 ).

Figures

Figs 1–10. Tarehylava avymaina gen. & sp. nov. 1 – habitus, lateral view; 2 – same, dorsal view; 3 – anterior part of body, dorsal view; 4 – same, ventral view; 5 – tegmen, outline; 6 – posterior part of tegmina, dorsal view; 7 – hind wing; 8– Madagascar, physical map, with area enclosed by the black square enlarged in Figs 9 and 10; 9 – distribution of T. avymaina gen. & sp. nov. in Madagascar (red points); 10 – same, ecoregions.

Figs 11–16. Tarehylava avymaina gen. & sp. nov., SEM micrographs. 11– anterior part of body, dorsal view; 12 – vertex and pronotum, dorsal view; 13 – anterior part of body, dorso-lateral view; 14 – lateral lobes of pronotum, frontal view; 15 – frons and clypeus, frontal view; 16 – same, oblique dorso-frontal view.

Figs 17–22. Tarehylava avymaina gen. & sp. nov., SEM micrographs. 17 – connection of frontal carinae, frontal view; 18 – same, fronto-lateral view; 19 – upper part of head, lateral view; 20 – lower part of frons and clypeus, frontal view; 21 – lower parts of head and pronotum, lateral view; 22 – antenna, dorso-frontal view.

Figs 23–28. Tarehylava avymaina gen. & sp. nov., SEM micrographs. 23 – apex of antenna; 24 – antennal plate organs; 25 – hing leg, ventral view; 26 – distal part of hind tibia and tarsus, ventral view; 27–28 – apical part of hind tibia and basimetatarsomere, ventral view.

Figs 29–34. Tarehylava avymaina gen. & sp. nov., tegmen, SEM micrographs. 29 – lateral view; 30 – tegmina, dorsal view; 31 – median part of tegmen; 32 – basal part of tegmen; 33 – apical part of costal area and costal cell; 34 – clavus.

Figs 35–40. Tarehylava avymaina gen. & sp. nov., tegmen, SEM micrographs. 35 – clavus, dorsal view; 36 – apical part of tegmina, dorsal view; 37 – apex of clavus and margin between coriaceous and membranous parts of tegmen; 38–40 – details of venation of membranous part.

Figs 41–46. Tarehylava avymaina gen. & sp. nov., female abdomen and terminalia, SEM micrographs. 41 – lateral view; 42 – anal tube, lateral view; 43 – gonoplac, lateral view; 44 –dorsal view; 45 – anal tube, dorsal view; 46 – ventral view.

Figs 47–52. Tarehylava avymaina gen. & sp. nov., female terminalia,SEM micrographs. 47 – pregenital sternite,ventral view; 48 – terminalia,ventral view; 49 – apex of gonoplac, dorsal view; 50 – terminalia, dorso-lateral view; 51 – posterior margin of gonoplac; 52 – teeth on posterior margin of gonoplac.

Figs 53–63. Tarehylava avymaina gen. & sp. nov., female abdomen and terminalia. 53 – abdomen, dorsal view; 54 – same, ventral view; 55 – same, lateral view; 56 – anal tube, dorsal view; 57 – same, lateral view; 58 – pregenital sternite; 59 – gonoplac, lateral view; 60 – gonapophysis VIII and endogonocoxal process, lateral view; 61 – gonapophyses IX and gonospiculum bridge, dorsal view; 62 – same, lateral view; 63 – spermatheca. Figs 53 – 55 were taken of the dry abdomen, Figs 56–62 after its maceration in KOH.