Dichaetomyia quadrata (Wiedemann)

Couri, Marcia S., Pont, Adrian C. & Daugeron, Christophe, 2010, The Muscidae (Diptera) of Vanuatu, Zootaxa 2556 (1), pp. 1-39 : 17-18

15. Dichaetomyia quadrata (Wiedemann)

Anthomyia quadrata Wiedemann, 1824: 52 . Lectotype male, Batavia [= Jakarta], Java, in ZMUC, des. Pont (1997: 110). Dichaetomyia quadrata ; Pont, 1989: 684.

Diagnosis. Scutum dark brown, yellow laterally, with grey pollinosity and with four dark brown vittae, the lateral pair on the boundary of the grey/yellow areas; dorsocentrals 2+4; scutellum entirely yellow, broader than long and with dark discal setulae extending on to lateral and sometimes also on to ventral surfaces; legs yellow; fore tibia without submedian posterior seta.

Material examined. BMNH: Vanuatu: Banks: Santa Maria, Gaua, Nombur , 8.x.1922, 1 ♂, T.T. Barnard; Navua Lava, x.1929, 1 ♂; xi.1929, 1 ♀, L.E. Cheesman . Malekula: ii.1930, 1 ♀, L.E. Cheesman .

BPBM: Vanuatu: Ambrym: 22.viii–4.ix.1967, 1 ♀, J. & M. Sedlacek . Éfaté: SW, Limestone, Plateau N. of Maat , 100 m, 17.viii.1957, 3 ♂, 3 ♀, J.L. Gressitt . Erromango: 11 km W of Ipota , 100–200 m, 2 ♂ (1 MNRJ), ii.1970, N.L.H. Krauss . Espiritu Santo: SW, Tasmalum , 3 m, 4.ix.1957, 1 ♂, ex fresh human excrement, J.L. Gressitt; Narango, 90 m, vi.1960, 4 ♂, W.W. Brandt; Luganville, 20.vii.1958, 1 ♂, B. Malkin . Malekula: Lamap , 8–21.xi.1967, 1 ♂, 4 ♀; 19–21.ix.1967, 2 ♂ ( MNHN & BMNH), 5 ♀ (1 MNHN, 1 MNRJ, 1 BMNH), J. & M. Sedlacek .

Comments. The species was first recorded from Vanuatu by Pont (1989). Emden (1965: 337–338) recognised two subspecies of quadrata : ssp. quadrata s. str. with abdominal tergites 4 and 5 very thinly dusted and appearing shagreened; and ssp. monticola Emden with tergite 5 entirely undusted except at extreme base of lateral surface and therefore appearing glossy. The BMNH Vanuatu material was determined by ACP in 1966 as having tergite 4 shagreened and tergite 5 glossy and thus appears to be closest to Emden’s ssp. monticola which is otherwise known only from the Oriental Region. Further study needs to be made of these morphological “subspecies”, and of quadrata throughout its range, before their exact status can be assessed

Distribution. Bellona I., Indonesia (West Papua), PNG (Bismarck Arch, PNG), Rennell I., Solomon Is, Vanuatu; Oriental Region.