Coenosia pumilio Stein, 1900

Couri, Marcia S., Pont, Adrian C. & Daugeron, Christophe, 2010, The Muscidae (Diptera) of New Caledonia 2503, Zootaxa 2503 (1), pp. 1-61 : 45-46

32. Coenosia pumilio Stein

Coenosia pumilio Stein, 1900b: 151 . Lectotype male, Aitape, Papua New Guinea, in ZMHU, des. Pont (1969b: 88). Coenosia pumilis [sic]; Curran, 1929: 7.

Coenosia pumilio ; Pont, 1989: 695; Shinonaga et al., 1991: 333.

Diagnosis. Small species, 2.0–3.0mm; frons yellowish to brownish; antenna short and yellow, brownish in female, postpedicel with a slight point anteriorly at tip; palpus yellow; scutum uniformly grey dusted, without (male) or with (female) a pair of narrow brown vittae; 1 proepisternal seta; lower calypter projecting well beyond upper one; legs yellow; male tibiae without submedian setae; mid femur with 0 anterior and 1 posterior preapical setae.

Description. As this species has not been described since Stein’s original description over a century ago, we are giving here a re-description of both sexes based on the lectotype and our New Caledonian material.

Length. Body: 3.0mm; wing: 2.5 mm.

Head. Ground-colour black, but frontal vitta mostly orange (male) or yellow in front (some females); all setae black. Fronto-orbital plate, parafacial, face, gena and lower occiput silvery-white pruinose; upper occiput and ocellar tubercle grey. Frontal vitta silvery pruinose (male) or dull grey (female) when viewed directly from below; frontal triangle not visible. Eye bare. Ocellar seta fine, subequal to orbital. 2 pairs of fine inclinate frontal setae, one at lunule, one halfway towards vertex, without interstitials; upper frontal closer to orbital than to lower frontal. Fronto-orbital plate narrow, at level of upper frontal seta about 1/6 width of frontal vitta at this point. Antenna yellow (male), or black with only dorsum of pedicel yellowish (female). Postpedicel short, about twice as long as broad, with a small point anteriorly at tip. Arista short-pubescent, the longest hairs shorter than its basal width. Parafacial slender, as slender as a fronto-orbital plate, not tapering much below. Gena below lowest eye-margin just over width of postpedicel. Mentum of proboscis dark brown. Palpus yellow, more dull in female.

Thorax. Ground-colour black. Scutum grey dusted, with a pair of fine brown vittae along the dorsocentral rows, more conspicuous in female than in male. Scutellum grey dusted, pleura light grey. Acrostichal setulae in two rows. Dorsocentrals 1+3. Inner postpronotal seta hair-like, less than half as long as outer seta. Anterior postsutural intraalar present but short. 1 proepisternal seta. Scutellum with the usual apical and subbasal lateral setae strong; disc virtually bare, with only 2 preapical discal setulae. Wing virtually clear, veins yellow; epaulet and basicosta yellow. Costal spine inconspicuous. Cross-vein r-m slightly basad of (male) or below (female) the point where vein R1 enters costa. Cross-vein m-cu straight, upright, slightly longer (male) or shorter (female) than apical section of vein CuA1. Calypters white, lower one projecting well beyond upper one. Halter yellow. Legs yellow, but coxae with some dark shadows, and apical tarsomeres browner. Fore femur with a row of fine posterodorsal and posteroventral setae. Fore tibia with a submedian posterior seta in female, absent in male. Mid femur without anteroventral setae, with 1–2 fine posteroventrals in basal half; 2– 3 anterior setae in basal half; 0 anterior and 1 posterior preapical seta. Mid tibia in female with 1 anterodorsal and 1 posterodorsal, the anterodorsal stronger and slightly closer to tibial apex than the posterodorsal; without these setae in male. Hind femur on anteroventral surface with 1 seta in basal half and 1–2 in apical half; 1 short posteroventral in basal half; about 6 setae in anterodorsal row; 1 dorsal preapical in addition to the anterodorsal. Hind tibia in male with the dorsal preapical 2/5 to 3/5 length of tarsomere 1, otherwise without setae; in female with 0 posterodorsal, 1 anterodorsal and 1 anteroventral, and the dorsal preapical half length of tarsomere 1 and at least twice as long as the anterodorsal preapical.

Abdomen. Ground-colour black, basal two segments often pale in male. Tergites grey dusted, in male with a pair of elongate paramedian dark spots on each tergite, these not very conspicuous and ill-defined but occupying the entire length of the tergites and thus giving the impression of two weak complete vittae; in female with syntergite 1+2 and tergite 3 unmarked, tergites 4 and 5 each with a pair of oval spots, those on tergite 5 rather faint. Sternite 1 bare.

Material examined: BPBM. New Caledonia: Bourail: iii.1959, 1 ♀, N.L.H. Krauss. La Foa: Beach near La Foa, 19.xi.1958, 1 ♀, C.R. Joyce. Hienghène: 0–50 m, i.1969, 1 ♀, N.L.H. Krauss. Isle of Pines: Point SW of Kuto, 0–5 m, 17.viii.1979, on grass, 1 ♂, 2 ♀ s, W. C. Gagné . Loyalty Islands: Lifou: We , 30–31.i.1962, 1 ♀, N.L.H. Krauss .

AMNH: New Caledonia: Plum Farm : 6.vi.1029, 1 ♂, T.D.A. Cockerell (identified by Curran, 1929: 7) .

OUMNH: New Caledonia: Grand Terre , Port Boise, near to the sea, light trap, 19.xii.2000, one ♀, S.T. Turvey .

Comments. Recorded from Plum Farm by Curran (1929) and, with some doubt, by Pont (1989). The occurrence of this species on New Caledonia is herein confirmed. Curran (op. cit.: 6) mentioned a female Coenosia that could not be identified, also collected at Plum Farm on 6 June. The characters that he mentions (“antennae and palpi black”) are those of female Coenosia pumilio , and, although this specimen could not be located in AMNH, it seems certain that it must have been correctly identified as C. pumilio .

Distribution. New Caledonia ( New Caledonia, Isle of Pines, Loyalty Is), PNG ( PNG),? Taiwan.