Haloscatella karekare, Mathis, Wayne N., Zatwarnicki, Tadeusz & Marris, John W. M., 2004

Mathis, Wayne N., Zatwarnicki, Tadeusz & Marris, John W. M., 2004, Review of unreported shore­fly genera of the tribe Scatellini from the New Zealand subregion (Diptera: Ephydridae) with description of three new species, Zootaxa 622, pp. 1-27 : 14-17

Haloscatella karekare , sp. nov. ( Figs. 15–23 )

Diagnosis. This species is distinguished from congeners by the following characters: Small shore flies, body length 1.50–1.70 mm; generally densely microtomentose, usually gray to brownish gray; gena high and lacking a genal seta; and wing with a maculation pattern of white spots on an infuscate background.

Description. Head: Frons slightly wider than long, microtomentose, generally appearing dull; mesofrons triangular, narrowed anteriorly, brownish gray to gray, more grayish laterad of ocellar triangle, lateral margin bearing 3–4 setulae; parafrons lighter in color than mesofrons, fronto­orbits brown to grayish brown anteriorly; ocelli forming an isosceles triangle; prominent setae (ocellar, vertical, and fronto­orbital setae) all subequal. Antenna black, generally unadorned except for macropubescence (especially evident on 1st flagellomere); arista short, length subequal to length of 1st flagellomere. Face uniformly tannish microtomentose, no prominent setae; ventroclinate facial setulae white. Parafacial gray, contrasted with tan face. Eye wider than high; eye ratio 1.15–1.25; slightly obliquely oriented. Gena concolorous with parafacial, genal height greater than 1/2 eye height; genato­eye ratio 0.50–0.70; genal seta lacking.

Thorax: Mesonotum brown medially between dorsocentral setae; scutellum slightly darker than medial, brown area of scutum; acrostichal setae short, mostly uniform in length, posteriormost pair slightly longer, in 2 rows; apical and basal scutellar setae subequal in length; lateral margins of mesonotum (postpronotum through supra­alar area) gray; posterior notopleural seta at elevated insertion compared to anterior seta; pleural area concolorous with lateral margin of mesonotum; only anepisternal seta along posterior margin well developed. Wing ( Fig. 15 ) fully developed, similar in males and females, maculate, generally infuscate with white spot on either side of crossvein dm­cu and in cell R4+5 at same level as white spot in cell M, some specimens with faint white area at apex of cell R4+5; costal vein ratio 0.20–0.25; M vein ratio 0.48–0.52. Legs generally densely microtomentose, gray; tarsi evenly grayish black; setulae on tibiae and tarsi whitish to appearing translucent.

Abdomen: Tergites densely microtomentose, mostly gray but with some pale tan to pale blue to green coloration; 5th tergite of male brownish gray; 5th sternite of male (Fig. 22) bar shaped, densely setulose. Male terminalia (Figs. 16–21): Epandrium in ventral view (Fig. 16) oval, narrowed posteriorly and anteriorly; cercal opening occupying posterior 1/3; cercus broadly allantoid with narrower apices, setulose; ventral margin somewhat truncate with a shallow, medial emargination, patch of setulae at ventral margin conspicuously more dense with setulae more approximate, epandrium in lateral view (Fig. 17) almost parallel sided; aedeagus in lateral view (Fig. 19) with basiphallus semihemispherical, apex as a digitiform projection, distiphallus membranous, almost twice length of basiphallus, surface structures shown in squares; phallapodeme in lateral view (Fig. 19) Lshaped, narrow, parallel sided; in ventral view (Figs. 20–21) trapezoidal; gonite in lateral view (Fig. 19) with apical projection narrow, parallel sided, digitiform, apex broadly rounded; hypandrium in lateral view (Fig. 19) somewhat like a skewed, very shallow C; gonites and hypandrium in ventral view (Figs. 19, 21) diamond­shaped with hypandrial arms sharply angulate, U­shaped, truncate basally at articulation with phallapodeme.

Type material. The holotype male is labeled “ NEW ZEALAND. N. Isl. AK: Karekare (37°00.2'S, 174°28.8'E) 10 October 2002 D. and W.N. Mathis/ USNM ENT 0 0 183773 [plastic bar code label]/ HOLOTYPE ɗ Haloscatella karekare Mathis Zatwarnicki & Marris [red].” The holotype is double mounted (minuten in a block of plastic), is in excellent condition, and is deposited in NZAC. Thirty­one paratypes (17ɗ, 14Ψ; AMNZ, NZAC, USNM) bear the same label data as the holotype but with the date of 1 Jan 2004.

Other specimen examined. NEW ZEALAND. South Island. SL: Riverton (46°22'S, 168°1.2'E; beach), 14–16 Jan 2004, W. N. Mathis (1Ψ; USNM). Although this female is probably conspecific, we lack a male to confirm its identity and have not included it in the type series.

FIGURES 16–22. Structures of the male terminalia of Haloscatella karekare ( New Zealand. AK: Karekare ). 16, Epandrium, and cerci, ventral view. 17, Same, lateral view. 18, Internal genitalic structures (aedeagus with basiphallus shaded, phallapodeme, gonite, and hypandrium), and 5th sternite, ventral view. 19, Same, lateral view. 20, Aedeagus (shaded) and phallapodeme, ventral view. 21, Gonite and hypandrium, ventral view. 22, 5th sternite, ventral view.

Distribution. Australasian/Oceanian: New Zealand (AK, SL).

Etymology. The species epithet, karekare , is a noun in apposition and refers to the type locality, which is a beach on the Tasman Sea just to the west of Auckland.

Natural history. This species was found in depressions just behind large beach dunes where there were shallow and largely ephemeral pools of brackish water. The pools had emergent sedges and small algal mats on some of the surface ( Fig. 23 ).

The type locality, Karekare , is a beach on the Tasman Sea where both marine and freshwater habitats converge. Shore flies occurring there are diverse and often abundant, probably as a reflection of the varied habitat. We have recorded over 20 species of shore flies, including six that are apparently undescribed, from the site. Among the more abundant, and in that sense dominant species, are: Psilopa metallica (Hutton) , Hydrellia enderbii (Hutton) , H. tritici Coquillett (an introduction), Hecamede granifera (Thomson) (the most abundant shore­fly species at the site); Ephydrella assimilis (Tonnoir and Malloch) , Scatella (Scatella) nitidithorax Malloch , and S. (Neoscatella) vittithorax Malloch (also an introduction).

Remarks. This species is very distinctive and somewhat anomalous among species of Haloscatella in the maculation pattern in the wing, which is atypical for Haloscatella . However, structures of the male terminalia clearly show that this species is aligned with congeners of Haloscatella . Within Haloscatella this species is similar to H. dichaeta , which occurs in the Afrotropical and Palearctic Regions. It differs from this species in the maculation pattern of the wing and structures of the male terminalia.

Figures

FIGURE 23. Karekare, the type locality of Haloscatella karekare.

FIGURES 13 – 15. Wings of Haloscatella species. 13, H. balioptera (New Zealand. Chatham Island: Tennants Lake). 14, H. harrisoni (New Zealand. Bounty Islands. Depot Island). 15, H. karekare (New Zealand. AK: Karekare).