Parahyadina latistylis, Mathis & Zatwarnicki, 2019

Mathis, Wayne N. & Zatwarnicki, Tadeusz, 2019, Revision of the Shore-fly Genera Parahyadina Tonnoir and Malloch and New Zealand Hyadina Haliday (Diptera: Ephydridae), Zootaxa 4623 (3), pp. 401-440 : 434-437

Parahyadina latistylis , sp. nov.

( Figs. 53–58 , Map 11 )

Diagnosis. This species is distinguished from congeners by the following combination of characters: Adults. Small shore flies, body length 1.23–1.77 mm.

Head ( Figs. 53–54 ): Lateroclinate fronto-orbital seta well developed, basal diameter comparable or only slightly reduced compared to basal diameters of vertical setae.

Thorax ( Figs. 53–54 ): Postsutural scutum with distinct, longitudinal vittae in rows between acrostichal setae and dorsocentral setae; 2 pairs of posterior dorsocentral setae, anterior seta shorter than posterior seta. Wing hyaline; costal section II shorter in length than costal section III; costal vein ratio 1.12–1.27; M vein ratio 0.30–0.32.

Abdomen: Tergites 3–5 with ventrolateral margin shallowly rounded; male tergite 5 extended posteriorly in same plane as tergite 4. Male terminalia. ( Figs. 55–58 ) Epandrium in posterior view ( Fig. 55 ) an oval to almost diamond-shaped, lateral margins somewhat angulate, each surstylus subrectangular, ventral margin emarginated medially, bearing 4 longer setulae on ventral portion and with an apical, prominent setula, in lateral view ( Fig. 56 ) with epandrium very narrow and straight, surstylus expanded, irregularly and broadly lanceolate, apical setulae prominent; cercus in posterior view ( Fig. 55 ) irregularly oblanceolate, pointed tapered to narrowly rounded point dorsally, ventral margin broadly rounded, in lateral view ( Fig. 56 ) irregularly semihemispherical, height almost twice width, dorsal margin rounded, posterior margin tapered to rounded point, generally covered with small setulae; aedeagus in lateral view ( Fig. 58 ) comparatively small, length about half that of phallapodeme, L-shaped, with extended, basal arm much narrower, digitiform, than length of aedeagal body, main structure, thumb-like apex broadly rounded, in ventral view ( Fig. 57 ) only slightly longer than basal width, truncate basally and apically, lateral margin tapered toward apex; phallapodeme in lateral view ( Fig. 58 ) elongate, moderately narrow, base with short, anteriorly directed projection, just beyond midlength with a robust, large projection, thereafter tapered slightly to narrowly truncate apex, in ventral view ( Fig. 57 ) elongate, narrow with 2 cross bars, one at base, the other sub-basally, thereafter parallel sided, narrow; gonite and hypandrium broadly fused, in lateral view ( Fig. 58 ) robustly L-shaped, gonal portion shorter than hypandrial portion, margins sinuous and tapered to narrowly rounded apex, hypandrial portion, narrow, somewhat elongate, in ventral view ( Fig. 57 ) wider than long, robust with large, tapered posterolateral extension, apex bearing 2 minute, dentate setulae, anterolateral angle also extended as a process that is parallel sided at base then tapered to pointed apex.

Type Specimen. The holotype male is labeled “ NEW ZEALAND. N. Isl. TO: Tokaanu (37°58.2’S, 175°46.2’E), 3–5 January 2004 [,] W. N. Mathis / USNM ENT 00026320 [plastic bar code label]/ HOLOTYPE ♂ Parahyadina latistylis Mathis & Zatwarnicki NZAC [red].” The holotype is double mounted (minuten in a plastic block), is in excellent condition, and is deposited in the NZAC. Forty paratypes (15♂, 25♀; NZAC, USNM) bear the same label data as the holotype .

Type locality. New Zealand. North Island. TO: Tokaanu (37°58.2’S, 175°46.2’E) .

Other specimens examined. NORTH ISLAND. NORTH ISLAND. BP: Paradise Valley (38°07.9’S, 176°09.9’E), 7 Feb 1998, W. N. Mathis (1♂, 1♀; USNM). ND: Hailes Road (quarry; 35°31.1’S, 174°25.8’E), 19 Feb 1998, W. N. Mathis (1♂; USNM). TO: Ikawhenua Range (E of Te Whaiti; 38°28.3’S, 176°59.4’E; 350 m), 4 Nov 1977, E. I. Schlinger (1♂; NZAC). WI: Mangawhero River (39°34.5’S, 175°15.7’E; 275 m), 9 Nov 1977, E. I. Schlinger (1♂; NZAC) .

SOUTH ISLAND. CO: Danseys Pass (2.2 km NE; 44°56.9’S, 170°24.2’E; 586 m), 11 Jan 2004, W. N. Mathis (3♂; USNM) . KA: Hapuku Stream (42°13’S, 173°45.3’E; 420 m), 8 Jan 2004, W. N. Mathis (1♂; USNM) ; Seddon (Awatere River; 41°39.6’S, 174°04.6’E), 14 Feb 1998, W. N. Mathis (5♂; USNM) . FD: Monowai River (45°46.7’S, 167°35.7’E; 171 m); 17–18 Jan 2004, W. N. Mathis (2♂; USNM) . MC: Acheron River (43°19.7’S, 171°40.5’E; 772 m), 10 Jan 2004, W. N. Mathis (1♂; USNM) ; Lake Lyndon (43°17.6’S, 171°42.5’E), 15 Feb 1998, V. Hollmann, W. N. Mathis (10♂, 5♀; NZAC, USNM) ; Lake Pearson (43°05.6’S, 171°46.8’E; 612 m); 3 Feb 2004, W. N. Mathis (1♂; USNM) ; Simois Stream (43°17.8’S, 171°32.9’E; 130 m), 10 Jan 2004, W. N. Mathis (2♂; USNM) . OL: Kingston (45°19.8’S, 168°42.7’E; 319 m); 26 Jan 2004, W. N. Mathis (1♂; USNM) ; Moke Lake (3.5 km S; 45°02.2’S, 168°34.7’E; 616 m); 28 Jan 2004, W. N. Mathis (1♂; USNM) . SL: Cascade River (46°15.6’S, 167°54.6’E; 73 m); 15 Jan 2004, W. N. Mathis (1♂; USNM) ; Orepuki (46°17’S, 167°44.3’E), 8 Feb 1976, L. L. Deitz (1♂; NZAC) ; Te Waewae Lagoon (46°12.3’S, 167°38.1’E); 19 Jan 2004, W. N. Mathis (1♂; USNM) .

Distribution ( Map 11 ). Australasian/Oceanian: New Zealand. North Island (BP, TO, WI), South Island (CO, KA, FD, MC, OL, SL).

Etymology. The species epithet, latistylis , is of Latin derivation and means broad or wide style, referring to the shape of the surstylar apex.

Remarks. External structures of the male terminalia of this species are similar to those of P. debilis , especially the robustly developed, apical extension of the surstylus. The shape of the gonites, however, differ considerably and distinguish this species, especially the anterior extensions that are tapered and flared laterally ( Figs. 57–58 ), not bifurcated and oriented anteriorly, as in P. debilis .

Figures

MAP 11. Parahyadina latistylis.

FIGURES 53–54. Parahyadina latistylis sp. nov. (male; New Zealand. N. Isl. TO: Tokaanu). 53. Antero-oblique photo of head and thorax (Scale bar = 0.2 mm). 54. Same, close up.

FIGURES 55–58. Parahyadina latistylis sp. nov. (male; New Zealand. North Island. TO: Tokaanu). 55. Epandrium, cerci, and surstyli, posterior view. 56. Same, lateral view. 57. Internal structures of male terminalia, ventral view. 58. Same, lateral view (scale bar = 0.1 mm).