Parahyadina hennigi, 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 : 426-427

Parahyadina hennigi , sp. nov.

( Figs. 37–42 , Map 8 )

Parahyadina lacustris of authors, not Tonnoir & Malloch 1926 [misidentification].— Zatwarnicki & Ryczko 2014: 502 [description, phylogeny, illustration of male terminalia].

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

Head ( Figs. 37–38 ): Lateroclinate fronto-orbital seta well developed, basal diameter comparable or only slightly reduced compared to basal diameters of vertical setae.

Thorax ( Fig. 37 ): 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, inserted near suture. Wing hyaline; Costal vein ratio: 0.97; M vein ratio 0.35.

Abdomen: Male terminalia ( Figs. 39–42 ): Epandrium in posterior view ( Fig. 39 ) generally almost circular with a ventral gap, mostly a relatively thin band, in lateral view ( Fig. 40 ) with dorsal 2/3 band-like, narrow, ventral third expanded, spatulate; surstylus in posterior view ( Fig. 39 ) narrowly triangular, with setulae along lateral margin, in lateral view ( Fig. 40 ) somewhat rectangular with posteroventral angle extended; cercus large, bearing scattered setulae, in posterior view ( Fig. 39 ) irregularly oval, in lateral view ( Fig. 40 ) hemispherical; aedeagus in lateral view ( Fig. 42 ) robustly comma-like, base wide, basal margin deeply excavated, apical 2/3 gently curved, tapered, apex rounded, in ventral view ( Fig. 41 ) elongate, almost parallel sided, at basal third with lateral, curved, digitiform process; phallapodeme in lateral view ( Fig. 42 ) longer than aedeagus, extended keel long, robust, rectangular, apex irregularly rounded, extension to aedeagal base slender, digitiform, in ventral view ( Fig. 41 ) clavate; gonite in lateral view ( Fig. 42 ) with basal half triangular, apical half elongate, slender, at an angle to basal portion, in ventral view ( Fig. 41 ) more or less an irregular triangular with basal curved, extended process toward aedeagal base pointed, apical process long and slender; hypandrium in lateral view ( Fig. 42 ) linear, sinuous, anteriorly with short, thumb- like processes, opposite end pointed, in ventral view ( Fig. 41 ) broad and short, anterior margin shallowly arched, posterior margin widely and deeply emarginate, broadly U-shaped with thinner, lateral arms extended posteriorly.

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Type Specimen. The holotype male is labeled “ NEW ZEALAND. S. Isl. CO:DanseysPass(2.2kmNE; 44°56.9’S, 170°24.2’E; 586 m), 11Jan2004, W. Mathis/ USNM ENT 00027416 [plastic bar code label]/ HOLOTYPE ♂ Parahyadina hennigi Mathis & Zatwarnicki NZAC [red].” The holotype is glued to a block of plastic elastomere (came off minuten while making dissection), is in good condition (abdomen removed and dissected), and is deposited in the NZAC.

Type locality. New Zealand. South Island. CO: Danseys Pass (2.2 km NE; 44°56.9’S, 170°24.2’E; 586 m) .

Other specimens examined. NORTH ISLAND . SOUTH ISLAND . KA: Marlborough Province , Molesworth (42°05.1’S, 173°15.5’E), 23 Mar 1976, W. J. Knight (1♀; BMNH) . OL: Southland , Mararoa River, The Key (45°32.7’S, 167°53.7’E), 29 Jan 1976, W. J. Knight (1♂, BMNH) .

Distribution ( Map 8 ). Australasian/Oceanian: New Zealand. South Island (CO, KA, OL).

Etymology. The species epithet, hennigi , is a Latinized genitive patronym to honor the contributions of Willi Hennig to the study of the acalyptrate Diptera and to the family Ephydridae specifically.

Remarks. This species is similar to P. irwini in having a comparatively short surstylus. Others structures of the male terminalia are substantially different from P. irwini and distinguish it, especially the shape of the hypandriumgonite structure that in lateral view ( Fig. 42 ) is bifurcate basally with the two finger-like prongs being perpendicular to the general plane of this structure. In addition, the hypandrium in ventral view ( Fig. 41 ) is wider than long (longer than wide in P. irwini ), and the extension of the phallapodeme going to the aedeagal base is very elongate, as long or longer that the length of the keel (in P. irwini , this extension is smaller, especially its length, compared to the length of the keel).

Figures

MAP 8. Parahyadina hennigi

FIGURES 37–38. Parahyadina hennigi sp. nov. (male; New Zealand. South Island. CO: Danseys Pass). 37. Antero-oblique photo of head and thorax (Scale bar = 0.2 mm). 38. Antero-oblique photo of head (Scale bar = 0.2 mm).

FIGURES 39–42. Parahyadina hennigi sp. nov. (male; New Zealand. South Island. CO: Danseys Pass). 39. Epandrium, cerci, and surstyli, posterior view. 40. Same, lateral view. 41. Internal structures of male terminalia, ventral view. 42. Same, lateral view (scale bar = 0.1 mm).