Dasyrhicnoessa pallida, 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 : 42-44

Dasyrhicnoessa pallida n.sp.

Figs. 18–19

Type material. HOLOTYPE 3 Australia, Queensland “Mangroves. / Mackay, Q. / 19 Jan. 1967. // D. McAlpine & / G. Holloway coll. // HOLOTYPUS / Dasyrhicnoessa / pallida sp.n. 3 / L. Munari des.” AM K186741 . 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 Australia, Queensland: same data as holotype, 233 6♀♀. The holotype and most of the paratypes are deposited in AM , a couple of paratypes are preserved in MCV .

Description. Size. Body length 2.2 mm (2.1–2.5), wing length 1.8 mm (1.7–2.0), wing width 0.7 mm (0.6–0.8).

Habitus. Yellowish to greyish yellow species with setal vestiture dark brown to blackish. Wings yellowish grey. Head. Yellow, except for frons reddish yellow having orbital vittae distinctly lighter and usual golden yellow patch on both sides of ocellar triangle; paravertical setae well developed, thin, inclinate; inner vertical seta inclinate, strong, about as long as lateroclinate outer vertical seta; postocular and postgenal setae short, former ones in single row; upper postocular seta long, inclinate towards inner vertical seta. Ocellar triangle bearing pair of moderately long, thin pseudopostocellar setae in addition to pair of strong ocellars; a few very 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; 6 short, strong, additional setulae before anterior orbital seta, between this one and anterior margin of orbital vitta; 3 pairs of frontal setae intercalated with 3 pairs of short, thin setulae, all setae and setulae inclinate, frontal setae often cruciate at apex. Antenna with large and pubescent postpedicel, bearing blackish, microscopically pubescent arista. Eye micropubescent, large, slightly oblong vertically, its longest diameter priapus n.sp.: (20) lateral view, (21) posterior view, (22) apex of distiphallus. Scale bars: 0.1 mm.

4.6× as long as genal height; 6 blackish peristomal setae, three anterior ones, including vibrissa, long and strong. Mouth parts pale yellow, with labellum stumpy, shorter than length of buccal cavity, and palpus long, slightly clavate, bearing scattered black setulae. Thorax. Yellowish with scutum greyish, slightly darker than pleura and scutellum; 1+3 dorsocentral setae; 6 irregular 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 and before it 2–3 short and weaker setae; 2 postalars, external one distinctly longer and stronger; scutellum with 4 long marginal setae; proepisternal seta long and strong, proepimeral one weak and slightly shorter; anepisternum with scattered setulae, bearing 2–3 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 few pale brownish to black long setae, and femur with posterodorsal and posteroventral rows of spaced, long setae; fore femur without true ctenidium, only with simple row of very short, thin setulae anteroventrally on distal half; mid femur of male with posteroventral comb of spine-like, short, subequal in length, slightly but distinctly curved forward, black setae on distal half. All legs, including coxae, yellow; last tarsomere not or indistinctly infuscated. Wing. Veins yellowish, membrane yellowish 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 before middle of cell dm; crossvein dm-cu distinctly shorter than one third of last section of CuA 1; halter yellow. Abdomen. Mostly yellowish to brownish yellow, with median, longitudinal, brown stripe, and setal vestiture formed by golden brown setae and setulae; transverse stripes at posterior edge of tergites yellow, hardly discernible. Male terminalia ( Figs. 18–19). Epandrium bearing some long setae dorsally and ventrolaterally, and several short setae on all remaining posterior surface; cercus of normal size, dorsally covered with microscopic hairs and with long setae; anterior surstylus short, straight, narrow, bearing few apical, thin setae; posterior surstylus lobe-shaped, distinctly squat in caudal view, bearing many short setae and apical cluster of stout tubercles on inner side; aedeagal apodeme long and straight; ejaculatory apodeme stumpy, with distal fan moderately though distinctly developed; distiphallus long and slender, ribbon-like, with evident micropubescence on basal half as well as subapically.

Female. Similar to male, except for slight sexual dimorphism. Female terminalia. Cerci long, straight, bearing thin setulae dorsally and apically; spermathecae spherical to subspherical, in a few paratypes with chitinous wall surrounding spermathecal duct opening distinctly invaginated (possibly collapsed).

Distribution. Australia (QLD).

Remarks. In this species the lateral profile of the male terminalia vaguely resembles that of Dasyrhicnoessa mathisi Munari even though the latter species has the anterior surstylus noticeably longer and stouter. Additionally, the two species are easily separable by the different colour of the body and legs.

Etymology. From the Latin pallidus meaning pale.The specific epithet refers to the pale hue of the body in this new species.