Parahyadina atra, 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 : 412-415

Parahyadina atra , sp. nov.

( Figs. 11–16 , Map 3 )

Diagnosis. This species is distinguished from congeners by the following combination of characters: Adults. Small to moderately small shore flies, body length 1.70–2.08 mm.

Head: ( Figs. 11–12 ): Lateroclinate fronto-orbital seta well developed, basal diameter comparable or only slightly reduced in comparison to basal diameters of vertical setae.

Thorax ( Fig. 11 ): Wing amber; costal section II equal in length or longer than costal section III; costal vein ratio 0.90–0.94; M vein ratio 0.28–0.32.

Abdomen: Tergites with ventrolateral margins pointed; male tergite 5 extended posteriorly in same plane as tergite 4. Male terminalia ( Figs. 13–16 ): Epandrium in posterior view ( Fig. 13 ) as inverted, irregular U, surstyli oriented slightly medially, widest at ventral level of cerci, in lateral view ( Fig. 14 ) with dorsal, epandrium linear, more or less parallel sided, widest at level of fusion with surstyli; surstylar length (from level of fusion) subequal to cercal height, angled very slightly posteromedially, in lateral view ( Fig. 14 ) with a medial, obtuse protrusion dorsally, thereafter ventrally tapered to narrowly rounded apex, apex bearing a single, short setula, also bearing 3 larger setulae in a vertical line along anterior margin at midlength, length of these setulae twice that of apical setula; cercus in posterior view ( Fig. 13 ) irregularly ovate, generally covered with small setulae, in lateral view ( Fig. 14 ) height almost twice width with anterior margin somewhat straight, posterior margin somewhat symmetrically but unevenly arched; aedeagus heavily sclerotized, in lateral view ( Fig. 16 ) narrowly tubular, elongate, with base shallowly bifurcate with asymmetric, short arms, thereafter apically as moderately abruptly curved, gradually tapered to moderately rounded apex, in ventral view ( Fig. 15 ) irregularly hexagonal, basal margin wide, shallowly and broadly invaginated, both lateral margins relatively short, thereafter margin angled medially to moderately broad apical truncation; phallapodeme in lateral view ( Fig. 16 ) irregularly triangular, aedeagal angle digitiform, short, hypandrial angle at 90 degrees, keel elongate slightly tapered, moderately broadly truncate apically, in ventral view ( Fig. 15 ) very narrowly triangular, like a spear point, with wider base symmetrically bifurcate, arms short, basal margin widely and shallowly invaginated, thereafter tapered to narrow apex with subapical slight widening; gonite and hypandrium broadly fused, in lateral view ( Fig. 16 ) together robustly L-shaped, gonal portion shorter but more robust, bearing a shallowly triangular, sub-basal projection and an apical, digitiform projection that bears 2 tiny, spine-like setulae, hypandrial portion much longer than wide, narrowly rectangular, lateral margins irregularly sinuous, in ventral view ( Fig. 15 ) generally irregularly rectangular, basal margin wide, shallowly convex, each lateral corner narrowly pointed, 2 apical extensions broadly digitiform, bearing tiny, medial and apical spine-like setulae.

Type Specimen. The holotype male of Parahyadina atra is labeled “ NEW ZEALAND. S. Isl. CO:DanseysPass(1.2 kmSW; 44°57.2’S, 170°22.0’E; 856m), 11 Jan2004, W.N.Mathis/ USNM ENT 00027373 [plastic bar code label]/ HOLOTYPE ♂ Parahyadina atra Mathis & Zatwarnicki NZAC [red].” The holotype is double mounted (minuten in block of plastic elastomer), is in excellent condition, and is deposited in NZAC . Seven paratypes (3♂, 4♀) bear the same label data as the holotype . Other paratype as follows: New Zealand. South Island . CO: Danseys Pass (44°56.7’S, 170°34.1’E; 245 m), 12 Jan 2004, W. N. Mathis (2♂, 2♀; USNM) ; Danseys Pass (2.2 km NE; 44°56.9’S, 170°24.2’E; 586 m), 11 Jan 2004, W. N. Mathis (1♂, 2♀; USNM)

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Type locality. New Zealand. South Island. CO: Danseys Pass (1.2 km SW; 44°57.2’S, 170°22.0’E; 856 m) .

Other specimens examined. NORTH ISLAND. TO: Tokaanu (37°58.2’S, 175°46.2’E), 3–5 Jan 2004, W. N. Mathis (3♀; USNM).

SOUTH ISLAND. CO: Danseys Pass (44°56.7’S, 170°34.1’E; 245 m), 12 Jan 2004, W. N. Mathis (2♂; USNM). FD: Borland Saddle (22 km W Monowai; 45°44.8’S, 167°23.2’E; 945–988 m); 18 Jan 2004, W. N. Mathis (1♂; USNM); Monowai River (45°46.7’S, 167°35.7’E; 171 m); 17–18 Jan 2004, W. N. Mathis (7♂, 2♀; USNM). KA: Hapuku Stream (42°13’S, 173°45.3’E; 420 m), 8 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 (2♂; USNM); Lake Lyndon (43°17.6’S, 171°42.5’E), 15 Feb 1998, W. N. Mathis (1♂; USNM). OL: Kingston (45°19.8’S, 168°42.7’E; 319 m); 26 Jan 2004, W. N. Mathis (1♂; USNM). SL: Riverton (beach; 46°22.0’S, 168°01.2’E); 14–16 Jan 2004, W. N. Mathis (1♀; USNM) .

Distribution ( Map 3 ). Australasian/Oceanian: New Zealand. North Island (TO), South Island (CO, FD, MC, OL, SL).

Etymology. The species epithet, atra , is of Latin derivation and means black, referring to the shiny, black abdomen of this species.

Remarks. Although similar to P. bulla and P. lacustris in having an elongated surstylus, this species is distinguished from these two species by having a straight surstylus (best seen in posterior view) and by the elongated, narrow, and acutely pointed aedeagus. In many specimens, the wing is faintly to conspicuously amber colored, somewhat similar to P. angusta , from which it is distinguished by the more slender, sickle-like aedeagus in lateral view ( Fig. 16 ), the longer than wide hypandrial-gonal structure in ventral view ( Fig. 15 ), and the shape of the apical, gonal process in lateral view ( Fig. 16 ).

Figures

MAP 3. Parahyadina atra.

FIGURES 11–12. Parahyadina atra sp. nov. (male; New Zealand. South Island. CO: Danseys Pass). 11. Antero-oblique photo of body (Scale bar = 0.2 mm). 12. Antero-oblique photo of head (Scale bar = 0.2 mm).

FIGURES 13–16. Parahyadina atra sp. nov. (male; New Zealand. South Island. CO: Danseys Pass). 13. Epandrium, cerci, and surstyli, posterior view. 14. Same, lateral view. 15. Internal structures of male terminalia, ventral view. 16. Same, lateral view (scale bar = 0.1 mm).