Parahyadina edmistoni, 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 : 423-426

Parahyadina edmistoni , sp. nov.

( Figs. 28 , 33–36 , Map 7 )

Diagnosis. This species is distinguished from congeners by the following combination of characters: Adults. Small to moderately small shore flies, body length 1.40–2.20 mm.

Head ( Fig. 28 ): Lateroclinate fronto-orbital seta evident but variable, weakly or well developed, if well developed then basal diameter comparable or only slightly reduced in comparison to basal diameters of lateral vertical setae.

Thorax ( Fig. 28 ): 2 pairs of posterior dorsocentral setae, anterior seta shorter than posterior seta. Wing hyaline; costal section II about equal in length to costal section III; costal vein ratio 0.95–1.05; M vein ratio 0.24–0.39

Abdomen: Tergites 3–5 with anterior margin extended ventroposteriorly as a pointed, well-sclerotized process; male tergite 5 tucked obliquely ventrad from plane of tergite 4. Male terminalia ( Figs. 33–36 ): Epandrium in posterior view ( Fig. 33 ) a relatively narrow, inverted, U-shaped band, arms slightly flared laterally and with medial extension for from cup-like receptacle for ventral portion of cercus; surstyli in posterior view ( Fig. 33 ) curved medially, tapered from base to apex, apical 2/3 almost parallel sided, apex truncate, ventral half bearing setulae laterally, lacking a prominent apical seta, in lateral view ( Fig. 34 ) epandrium straight, narrow, swollen at fusion with surstylus, surstylus swollen basally, thereafter abruptly narrowed, apical extension parallel sided, angularly truncate apically, bearing numerous setulae on ventral portion; cerci in posterior view ( Fig. 33 ) obovate, tapered to rounded point dorsally, base broadly rounded, in lateral view ( Fig. 34 ) semihemispherical; aedeagus in lateral view ( Fig. 36 ) slipper-shaped with narrow, slightly sinuous tongue, apex bluntly rounded, in ventral view ( Fig. 35 ) pear-shaped, wider basally, apical half narrowed, truncate at apex; phallapodeme in lateral view ( Fig. 36 ) with thumb-like, narrow extension toward aedeagal base, and much shorter extension toward hypandrium, keel robustly developed, elongate, rectangular, in ventral view ( Fig. 35 ) symmetric but unequal hour-glass shaped apical dagger-shaped, projection, base wide, rounded posteriorly, thereafter apically abruptly narrowed then with moderately wide cross piece, each lateral extension triangular, length of narrow, apical extension slightly greater than width of cross piece, tapered to narrow point; gonite/hypandrium broadly fused, in lateral view ( Fig. 36 ) generally forming L-shaped structure with apical arm broader and shorter than basal arm, external angle of L with a digitiform process, base with shallow bifurcation, in ventral view ( Fig. 35 ) almost as wide as long, anterior margin broadly truncate, with subanterior lateral knob-like projections, then lateral margins shallowly concave, thereafter posteriorly with a subapical, short protrusion, posterior margin as 2 medially curved, parallel-sided digitiform processes, one process from each side that nearly touch posteromedially

Type Specimen. The holotype male is labeled “ New Zealand. N[orth] I[sland], ND, Hailes Road, quarry 37°[]sic, should be 35°] 31.1’S, 174°25.8’E [,] 19 February 1998, V. Hollmann-Schirmacher/ USNM ENT 00250355 [plastic bar code label]/ HOLOTYPE ♂ Parahyadina edmistoni Mathis & Zatwarnicki NZAC [red].” The holotype is double mounted (minuten in a plastic block), is in excellent condition, and is deposited in the NZAC. Ten paratypes (6♂, 4♀; USNM) bear the same label data as the holotype except for some (4♂, 3♀), W. N. Mathis was the collector.

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Type locality. New Zealand. North Island. ND, Hailes Road (quarry 35°31.1’S, 174°25.8’E) .

Other specimens examined. NORTH ISLAND. AK: Huia Dam (36°59.7’S, 174°33.9’E), 5–18 Feb 1998, W. N. Mathis (1♂; USNM) ; Karekare swamp (37°0.8’S, 174°28.8’E), 5 Feb 1989, V. Hollmann (1♂; NZAC) ; Mangere (36°58.7’S, 174°45.8’E), 6 Feb 1998, V. Hollmann, W. N. Mathis (3♂; NZAC, USNM) ; Waiheke Island , Palm Beach (36°46.7’S, 175°02.5’E), 27 Aug 1977, L. L. Deitz (1♂; NZAC) ; Whatipo (37°02.2’S, 174°30’E), 5 Feb 1998, V. Hollmann (1♂; NZAC) . BP: Paradise Valley (38°07.9’S, 176°09.9’E), 7 Feb 1998, W. N. Mathis (1♀; USNM) ; Paradise Valley , Rotoroa (38°07.7’S, 176°45.8’E), 6 Feb 1998, V. Hollmann (1♂, 1♀; NZAC) . TO: Lake Otamangakau (39°0.4’S, 175°37.1’E; 610 m), 5 Jan 2004, W. N. Mathis (3♀; USNM) .

SOUTH ISLAND . MC: Christchurch ( Styx Mill Reserve ; 43°27.8’S, 172°36.8’E; 9 m), 2 Feb 2004, W. N. Mathis (1♂, 3♀; USNM) ; Christchurch (Styx Mill Reserve; 43°28.1’S, 172°36.4’E), 17 Oct 2002, D. and W. N. Mathis (1♂, 1♀; USNM) ; Lake Pearson (43°05.6’S, 171°46.8’E; 612 m); 3 Feb 2004, W. N. Mathis (1♀; USNM) .

MK: Ahuiri Valley (near Ben Avon Stream; 44°24.5’S, 169°37.5’E), 2 Mar 1976, L. L. Deitz (1♀; NZAC) . NN: Graham Stream (41°11.9’S, 172°48.6’E), 12 Feb 1998, W. N. Mathis (1♂; USNM); Maitai Dam (41°17.6’S, 173°22.1’E), 11 Feb 1998, W. N. Mathis (1♂; USNM); Nelson (airport; 41°18.2’S, 173°13.6’E), 11 Feb 1998, V. Hollmann, W. N. Mathis (5♂, 9♀; NZAC, USNM) .

Distribution ( Map 7 ). Australasian/Oceanian: New Zealand. North Island (AK, BP, ND, TO), South Island (MC, MK, NN, OL).

Etymology. The species epithet, edmistoni , is a genitive Latin patronym to honor Father James F. Edmiston, O. F. M., Ph.D., a former colleague in the study of shore flies and a personal friend. Jim passed away on Sunday, May 18, 2008 (born 18 July 1954), and is still greatly missed. Before his untimely death, Jim had intended to participate in this study, primarily in adding a molecular analysis of the included species.

Remarks. Like specimens of H. breva , the lateroclinate fronto-orbital seta is weakly developed, in some specimens almost setula-like.Also like H. breva , the structures of the male terminalia are unique ( Figs. 33–36 ) and unlike the pattern for most congeners. The surstyli, for example, are robustly developed, elongated, mostly parallel sided, and are shallowly curved medially. The surstylar apex is also obliquely truncated and not acute. The keel of the phallapodeme ( Fig. 36 ) is also elongated and in lateral view appears rectangular in shape.

Figures

MAP 7. Parahyadina edmistoni

FIGURES 27–28. Antero-oblique photo of head and thorax (Scale bar = 0.2 mm). 27. Parahyadina debilis sp. nov. (female; New Zealand. South Island. OL: Mararoa River). 28. Parahyadina edmistoni sp. nov. (female; New Zealand. North Island. ND: Hailes Road).

FIGURES 33–36. Parahyadina edmistoni sp. nov. (male; New Zealand. North Island. ND, Hailes Road (quarry)). 33. Epandrium, cerci, and surstyli, posterior view. 34. Same, lateral view. 35. Internal structures of male terminalia, ventral view. 36. Same, lateral view (scale bar = 0.1 mm).