Cairnsimyia englishae, Mcalpine, David K., 2013

Mcalpine, David K., 2013, Supplementary descriptions of Australian Rhinotorini (Diptera: Heteromyzidae), Zootaxa 3680 (1), pp. 130-138 : 132-134

Cairnsimyia englishae n. sp.

Figs 3–5

Type material. Holotype 3. New South Wales: Mooney Mooney Creek, near Gosford [33°26ʹS 151°15ʹE], 1.i.1977, D.K. McAlpine (AM K358275). Double mounted on micro-pin through polyporus. Paratypes. New South Wales: 1 3, 1 Ƥ, same locality as holotype, Nov. 1975, Dec. 1976, D.K. McAlpine (AM).

Description (male, female).

Coloration. Head pale yellowish-grey; postfrons with reddish-brown markings; face predominantly pale with only one or two light brown spots just above centre; cheek region with one light brown mark centrally. Antenna largely grey; segment 2 darker; segment 3 partly tawny; arista dark brown. Prelabrum greyish-tawny; palpus greyish brown. Thorax tawny brown, with extensive pale grey to yellowish pruinescent markings, least developed on sternopleuron; scutellum tawny, pale yellow apically, dorsally with pale greyish pruinescence except on central region. Fore coxa brown with grey pruinescence; other coxae and femora tawny; tibiae yellowish, each with subbasal and apical brown zone; tarsi tawny-yellow, not noticeably darker distally. Wing hyaline, tinged with yellow basally, with numerous brown spots as in Fig. 3 . Halter yellow.

Head. Vertical excavation moderately deep; postfrons c. 0.44 as wide as total width of head; lateral extension of face below cheek extensive, but not as deep as in some species; the following cephalic bristles present: inner and outer vertical, rather stout postvertical, ocellar, only one rather large fronto-orbital, long vibrissa, several shorter cheek bristles in male, vestigial in female; postfrons anteriorly less strongly setulose than in some species (particularly C. uniseta ). Antennal segment 3 not longer than deep; arista arising distinctly beyond mid-length of dorsal surface of segment 3, with extensive very short pubescence not longer than half basal diameter of arista. Prelabrum rather short and rounded; palpus of moderate size; proboscis moderately short for genus.

Thorax. Scutellum distinctly longer than in C. robusta , C. uniseta etc. with almost straight lateral margins, with dorsal setulae sparser medially; prescutellar acrostichal bristle absent; often one of the mesopleural setulae near posterior margin slightly enlarged. Femora without spinescent ventral bristles; fore femur with few small posteroventral bristles distally, not located on a prominent ridge; mid femur with few differentiated mid-posterior bristles. Costa of wing slightly but distinctly thickened on proximal side of subcostal break, on this region bearing particularly short, thick black setulae; vein 2 slightly curved forward apically.

Abdomen. Male: epandrium somewhat narrowed posteriorly, with many moderately long setulae; surstylus asymmetrically almost obovate (broader than appearing in Fig. 4 because of angle of view), outer surface densely microtrichose on distal third and on more than posterior half of rest of length, with many setulae of various sizes and non-uniform arrangement, some forming a dense apical tuft; cercus small, setulose. Female: tergite 5 nearly as long as tergite 4, without median weakly sclerotised seam; cercus long and slender.

Dimensions. Total length, 3 5.0– 5.1 mm, Ƥ 4.5 mm; length of thorax, 3 2.9 mm, Ƥ 2.9 mm; length of wing, 3 5.7–5.8 mm, Ƥ 5.6 mm.

Distribution. Only known from type locality on Central Coast of New South Wales.

Notes. Cairnsimyia englishae is the only Australian species lacking both the prescutellar acrostichal bristle and the spinescent ventral femoral bristles, except for the far-northern C. aroana distinguished by its vestigial ocellar bristle, precipitous anterior marginal zone of the postfrons, and slightly elongate-ovoid antennal segment 3. The scutellum of C. englishae is more elongate than that of C. cavifrons , C. uniseta , and C. verticalis , and more like that of C. sydneiensis . The surstylus of the male ( Fig. 4 ) has a distinctive outline and compact apical tuft of setulae.

The adults of C. englishae were found on tree trunks in a rainforest vestige near a salt-water inlet. Cairnsimyia uniseta was more plentiful in the same habitat.

The specific epithet refers to Kathleen M.I. English, a former science teacher, who collected and described immature stages of Australian lower brachycerans, and obtained the first known rhinotorine larvae (see McAlpine 1968).

Figures

FIGURE 3 – 5. Cairnsimyia englishae, male. 3, right wing. 4, left surstylus and cercus, lateral view (scale = 0.2 mm). 5, head (setulae on postfrons omitted). c, cercus; ep, epandrium; ss, surstylus.