Zalea johnsi, McAlpine, 2007

McAlpine, D. K., 2007, The Surge Flies (Diptera: Canacidae: Zaleinae) of Australasia and Notes on Tethinid-Canacid Morphology and Relationships, Records of the Australian Museum 59 (1), pp. 27-64 : 48-50

Zalea johnsi n.sp.

Figs 15, 24, 25, 48, 50, 51

Material examined. HOLOTYPE?, New Zealand ( South Island ): Kaikoura Peninsula [East Head on some maps], 26–28.i.2000, D.K.M., R.M. ( NZAC). Dry-mounted on triangular card . PARATYPES. South Island : 5??, 2!!, same data as holotype ( AM, CMC, USNM); 6??, 2!!, Paratai Point, Kaikoura district, 26–27.i.2000, D.K.M., R.M. ( AM, NZAC, ZMC) .

Other material. South Island: 2!!, Jackson’s Bay, near Haast ( AM).

Description (?,!). Appearance and habitus resembling those of Z. minor , Z. horningi , etc.

Coloration. Head predominantly grey-brown; anterior margin of postfrons narrowly rather yellowish brown; parafacial and much of cheek yellowish with covering of pale grey pruinescence; hypofacial and posterior extremity of cheek darker, greyish. Antenna tawny-brown; segment 3 darker distally than basally; arista blackish. Prelabrum greybrown; palpus greyish tawny. Thorax with blackish ground colour; mesoscutum and scutellum with brown pruinescence; pleura with grey to greyish brown pruinescence. Legs, including tarsi, dark greyish brown. Wing membrane uniformly smoky grey; veins dark brown. Halter yellow, with pale creamy capitellum. Abdomen dark grey-brown, almost entirely pruinescent; in male, anterior surstylus shining brown, darkest towards base; in female, tergite 7 extensively shining black anteriorly, pruinescent dark grey towards posterior margin; cercus of female brown.

Head and eye both much higher than long; height of cheek c. 0.23–0.27 of height of eye; face almost flat and vertical (when uncollapsed), but recessed between parafacials on upper part; vibrissal region of cheek less anteriorly produced than in Z. major and Z. minor , so that the moderately short vibrissa is situated almost at its anterior extremity, as seen in profile; postgenal setulae absent; postvertical bristles divergent, much smaller than ocellars and fronto-orbitals. Palpus shorter than in Australian species, slightly widened distally.

Thorax. Prosternum with well sclerotized precoxal bridge; scutellum without setulae, with only the two pairs of major bristles. Mid femur of male with a mostly sparse series of posteroventral bristles, those just beyond mid-length shorter, slightly thickened, more closely placed, with curved sharp apices, forming ill defined comb; in female posteroventral bristles of mid femur absent or little differentiated from setulae; fore tibia generally with three or more dorsal to posterodorsal setulae or bristles, as long as or longer than tibial diameter; mid and hind tibiae also with some moderately long dorsal setulae or bristles. Wing: cell-4 index = 0.50–0.58.

Abdomen. Sternite 1 divided into two small, widely separated sclerites; sternite 2 without accessory sclerites. Male: epandrium coarsely setulose, without any distinct bristle pairs; anterior surstylus slender, much curved so that slender but compressed apical part is directed posteriorly, with scattered setulae longest on posterior surface of basal half, and with few microtrichia restricted to inner surface near apex; posterior surstylus broad, narrowly rounded at apex, strongly incised posteriorly at base to produce subbasal prominence, very extensively microtrichose except near anterior margin, outer surface with scattered small setulae and longer ones towards anterior margin, inner surface with large, stout setulae particularly developed towards base; each anterior papilla of aedeagus with lightly pigmented longitudinal strip, distally slender, smooth, tapering to fine point; posterior papilla stout, only gradually tapering to obtuse apex; distiphalus smooth, rather abruptly contracted before acuminate apex; cercus smaller than in Z. horningi . Female: sternites 2 to 6 not longer than wide; sternite 4 distinctly divided in two, but others entire or imperfectly divided; tergite 6 not markedly desclerotized on posterior margin; tergite 7 rather similar to that of Z. minor , weakly sclerotized rather than desclerotized medially, broad with much of posterior margin transverse (rather than narrowly rounded on each side as in Z. horningi and Z. sp. 1), with anterior part of tergite extensively shining black and glabrous, with posterior margin (often the only part visible in dried specimens) grey-pruinescent, with anterior apodeme not distinctly forked as it merges with thickened anterior margin of tergite; sternite 7 with pair of sclerites separated by c. twice width of each.

Dimensions. Total length,? 1.3–1.5 mm,! 1.5–1.6 mm; length of thorax,? 0.6–0.7 mm,! 0.6–0.8 mm; length of wing,? 1.5–1.7 mm,! 1.7–1.9 mm.

Distribution. New Zealand: South Island—northeast coast and apparently west coast. Only females are available from Jackson’s Bay on the west coast. It is desirable that males be obtained from this population to confirm its specific identity.

Notes

Zalea johnsi is very similar to Z. horningi which it resembles especially in the well-developed prothoracic precoxal bridge (often not easily visible in dried specimens), the position of the vibrissa very close to anterior extremity of cheek, the relatively long dorsal setulae on the tibiae, and, in the male, the broad, densely microtrichose posterior surstylus. Zalea johnsi is most readily distinguished from Z. horningi by the characters given in the key, also by those of the aedeagal papillae, distiphallus, and female abdominal sternites, as given in the descriptions. For comparison with other species of the horningi group see under those species, and particularly compare the figures of postabdominal structures.

The specific epithet refers to Peter M. Johns in recognition of his generous help and sharing of field knowledge during my field work in New Zealand.

omitted. (51) Z. johnsi , hypandrium and associated parts. ap, anterior papillae of aedeagus. ass, anterior surstylus. d, distiphallus. go, gonite. hc, hypandrial comb. hy, hypandrium. mpa, median posterior papilla.

pss, posterior surstylus. Both scales = 0.1 mm.

Figs 52, 53

Material examined. HOLOTYPE?, New Zealand: Whananaki South (35°'31.1'S 174°27.2'E), North Island, 6–8.x.2002, D.M., W.N.M. ( NZAC by agreement from USNM, 00184020). Dry-mounted on micro-pin through polyporus pith . PARATYPES New Zealand: 12??, same data as holotype but some 19.ii.1998 ( NZAC, AM, USNM); 3??, Sandy Bay (35°33.4'S 174°28.5'E), 6.x.2002, D.M., W.N.M. ( USNM) .

Description (?,! unknown). Very similar to Z. johnsi , agreeing with description of that species, except as indicated below.

Coloration. Agreeing with that of Z. johnsi .

Head. Height of cheek = 0.20–0.28 of height of eye; postvertical bristles generally convergent and proclinate, parallel in one specimen.

Thorax. Wing: cell-4 index = 0.49–0.57.

Abdomen. Anterior surstylus very attenuated but with similar curvature to that of Z. johnsi , with scattered, fine setulae, apparently without microtrichia, but densely minutely denticulate on small apical area; posterior surstylus broadly subovate, its distal margin broadly rounded, with no armature on anterior margin, nearly all setulae being scattered on inner surface but not particularly developed towards base, with central to posterior and apical parts of outer surface pruinescent, anterobasal part bare; each anterolateral papilla of aedeagus with slender obtuse apical section; posterior papilla massively swollen and rugose at sides where it overlies basiphallus, tapering to rounded apex; distiphallus rugose distally, not tapered.

Dimensions. Total length 1.2–1.4 mm; length of thorax 0.55–0.67 mm; length of wing 1.3–1.6 mm.

Distribution. New Zealand: North Island, Northland.

Notes

Identification of North Island species in the horningi group (other than Z. earlyi ) relies mainly on male postabdominal characters, especially the shape and armature of the surstyli. Associated females for these are largely absent, but there are indications that the female postabdomen may provide diagnostic characters for at least some species. Males of Z. mathisi are distinguished by the very attenuated, weakly setose anterior surstylus and the broadly subovate posterior surstylus with oblique base and very few or no setulae on its outer surface.

The specific epithet refers to Wayne N. Mathis, who collected the type series.