Dasyrhicnoessa ostentatrix, Munari, 2004

Munari, L., 2004, Beach Flies (Diptera: Tethinidae: Tethininae) From Australia and Papua New Guinea, with Descriptions of Two New Genera and Ten New Species, Records of the Australian Museum 56 (1), pp. 29-56 : 40-42

Dasyrhicnoessa ostentatrix n.sp.

Figs. 15–17

Type material. HOLOTYPE 3 Australia, New South Wales “ Swept Sea grass / Careel Bay, / Avalon , NSW. // 12 May 1984 / D.K. McAlpine / D.J. Bickel // HOLOTYPUS / Dasyrhicnoessa / ostentatrix sp.n. 3 / L. Munari des.” AM K186740 . The specimen is in excellent condition, and is double mounted (glued on the tip of a triangular card); abdomen dissected, stored in glycerol in a small plastic tube, and pinned below the specimen . PARATYPES (many specimens were prepared byAM technicians using the brochette double mounting method): Australia, New South Wales: same data as holotype, 4533 28♀♀ ; “ NSW: Broken Head / nr Byron Bay / 7–8 Nov. 2000

// Shoreline rocks / D.K. McAlpine ”, 3 33 2♀♀ ; “ Bundagen, via Repton / NSW 15 Jan. 1971 / D.K. McAlpine / & A. Hughes // MV lamp”, 1 3; “ Careel Bay / N. South Wales / 27 Oct. 1962 // Mangroves / D.K. McAlpine ”, 3 33 11♀♀ ; ibidem, “ 14 March 1963 // on beach / D.K. McAlpine”, 1 3; “ Careel Bay, / Avalon , NSW. / 15 Dec. 1964 // Mangroves”, 1 3 1♀ ; 14 June 1965, on beach, 533 5♀♀; 8 Nov 1975, 3933 25♀♀; “ Glenfield, near / Sydney, NSW / 2 April 1967 [or 1957?] // D.J. Lee / collector”, 1 3; “ Little Beach nr / Terrigal , NSW / 29 Jan. 1988 // On beach / D.K. McAlpine / and B.J. Day ”, 1 3; “Tidal flat, / Merimbula, NSW. / 12 Febr. 1963. / D.K. McAlpine ”, 6 33 2♀♀ ; “ North Creek, near / Ballina , NSW / 1 March 1965 / McAlpine & Lossin”, 4 33 10♀♀ ; “ Mangroves, Nth / Cronulla , NSW. / 21 Jan. 1962 / D.K. McAlpine”, 11 33 13♀♀ ; 29 Jan. 1962, 6233 58♀♀; 1 March 1962, 733; 31 March 1972, 4333 45♀♀. Australia, Victoria: “ Bunarong Cliffs 5 km / SW Inverloch, Vic. / 8 Apr. 1986 / D.K. McAlpine // On stranded kelp”, 1 3. The holotype and most of the paratypes are deposited inAM, some paratypes are preserved in MCV .

Description. Size. Body length 1.8 mm (1.2–2.1), wing length 1.8 mm (1.5–1.9), wing width 0.6 mm (0.5–0.6).

Habitus. Dark grey to ochreous yellow species, with setal vestiture dark brown to black. Wings yellowish grey. Head. Frons brownish yellow, with frontal and orbital vittae pale yellowish, and with golden brown patch on both sides of dark grey ocellar triangle, latter concolorous with postcranium; antennal postpedicel infuscated; face, parafacial, and gena pale yellow; gena with distinct, longitudinal, narrow, translucent stripe as in many species of Tethina Haliday ; paravertical setae long and thin; inner vertical seta inclinate, strong, about as long as lateroclinate outer vertical seta; postocular and postgenal setae short, former ones in 1–2 irregular rows; upper postocular seta long, inclinate towards inner vertical seta; ocellar triangle bearing pair of moderately long pseudopostocellar setae in addition to pair of strong ocellars; few short, thin setulae between ocellars and pseudopostocellars; 3 strong, lateroclinate orbital setae; row of thin, inclinate setulae on orbital vitta between two anterior orbitals and frontals; 3–4 short, additional setulae before anterior orbital seta, between this one and anterior margin of orbital vitta; 3 pairs of frontal setae intercalated with 3–4 pairs of short, thin setulae, all setae and setulae inclinate; antenna with brownish postpedicel, bearing short-haired, black arista; eye micropubescent, large, oblique, its longest diameter 5.2× as long as genal height; 6–7 black peristomal setae, three anterior ones, including vibrissa, long and strong; mouth parts pale yellowish, with labellum slightly shorter than length of buccal cavity; palpus long, slender, bearing scattered black setulae. Thorax. Dark grey to ochreous; 1+3 dorsocentral setae; 6 rows of acrostichal setulae on anterior half of scutum, otherwise arranged in 4 rows; prescutellar acrostichals long and strong; postpronotal lobe bearing 3 setae, each with different inclination, posterior seta long and strong, anterior setae shorter and weaker; 1 long presutural seta; 2 notopleurals about subequal in length; 1 supra-alar, below it 1 short seta; 2 postalars, external one distinctly longer and stronger; scutellum with 4 long marginal setae; both proepisternal and proepimeral setae present; anepisternum with few, scattered setulae (more numerous in most paratypes), bearing 3 long, posteriorly directed, posteromarginal setae, mid one distinctly longer and stronger, and 1 erect seta at posterodorsal margin; katepisternum with few, scattered setulae, bearing long and strong posterodorsal seta; anepimeron, katatergite, and meron without setae and setulae. Legs. Evenly setulose, bearing short, blackish setae and setulae, except for foreleg having coxa with scattered, black, long setae, and femur with posterodorsal and posteroventral rows of spaced, long, strong setae; ctenidium of fore femur formed by few (4 in holotype), weak, short, spinulae; mid femur of male with long row of spaced, spine-like, posteroventral black setae, decreasing in length distally; all legs, including coxae, yellowish grey; last two tarsomeres slightly infuscated. Wing. Veins pale brownish, membrane yellowish grey to grey; alula with fringe formed by long, erect, blackish setae; costal vein reaching end of M 1, bearing several, spaced, microscopic setulae on both dorsal and ventral surfaces; R 2+3 distinctly bisinuate, diverging from R 4+5 distally; R 4+5 and M 1 parallel; crossvein r-m ending on basal third of cell dm; crossvein dm-cu slightly shorter than one third of last section of CuA 1; halter yellowish. Abdomen. Dark brown to blackish, with tergites showing very narrow, apicomarginal, yellowish stripes; setal vestiture blackish. Male terminalia ( Figs. 15–17). Epandrium bearing long and strong setae on distal half, and several shorter setae on all remaining posterior surface; cercus of normal size, pubescent, dorsally covered with microscopic hairs and with long setae; anterior surstylus very small, slightly bent medially, bearing sparse, thin setae; posterior surstylus lobeshaped, with lateral profile variable in many paratypes ( Figs. 15–16), bearing several long setae and apical cluster of stout tubercles on inner side; aedeagal apodeme long, straight, only slightly bent distally; ejaculatory apodeme with distal fan well developed, more or less sclerotized; distiphallus long, ribbon-like, micropubescent.

Female. Similar to male, except for slight sexual dimorphism. Female terminalia. Cerci moderately long, setulose; spermathecae spherical, smooth.

Distribution. Australia (NSW, VIC).

Remarks. The new species shows a marked variability in coloration, with individuals having dark grey to ochreous yellow thorax, and with dark brown to black setal vestiture. That implies a considerable degree of difficulty in identifying the female specimens, unless they are strictly associated with several male specimens from the same biotope. In the preserved material, the males are easily distinguished from congeners in having the abdomen, when observed laterally, with the posterior surstyli distinctly and characteristically exposed outwards. Also, the lateral outline of the surstylus often exhibits a fair variability ( Figs. 15–16).

Etymology. From the Latin ostentatrix meaning exhibitionist, parading or showing. The specific epithet refers to the external male terminalia which are distinctly exposed outwards.