Atherigona (Acritochaeta) orientalis Schiner 1868

Atherigona orientalis Schiner, 1868: 295. Holotype female, Tellnschong, Nicobar Is, in NMW (type seen by Pont 1986: 18).

Atherigona orientalis; Pont, 1989: 682.

Diagnosis. Species exhibiting intraspecific variation in colour (see Pont 1986). Vanuatu specimens with frontal vitta brown to orange, or partly brown and orange; palpus yellow in male, brown in female with basal part orange; male palpus elongate and flattened; female palpus large and band-shaped; presutural acrostichal setulae in 4–5 rows; scutum grey dusted, without vittae or with three more or less distinct brown vittae, the median one not continuing on to scutellum; scutellum grey dusted; pleura dark in ground-colour; legs mostly yellow, fore femur yellow in male, black in female with yellow base and tip; mid femur with a single preapical posterior seta; hind femur with a dorsal preapical seta, rarely without; abdominal ground-colour black or orange in female; male without hypopygial prominence and trifoliate process; male terminalia as in Figs 41, 42 and female ovipositor as in Figs 15–16 and 45–47 (all in Pont 1986). See also Pont & Magpayo (1995).

Material examined. BMNH: Vanuatu: Malekula: Ounua, iii–iv.1929, 2 ♀ s, L.E.Cheesman (Pont 1992: 58).

BPBM: Vanuatu: Ambrym: 22–28.viii.1967, 3 ♀, J. & M. Sedlacek; south, 22.viii–4.ix.1967, 9 ♀, J. & M. Sedlacek; Ranon to Mt. Toyo, 0–500 m, 2.ix.1979, 1 ♂, W.C. Gagné, G.M. Nishida, G.A. Samuelson. Éfaté: NW, Maat (Mat. Ambrym Vill.), 3 m, 15.viii.1957, 1 ♀, J.L. Gressitt; Port Vila, 0–5 m, ii.1970, 1 ♂, 1 ♀; 0–100 m, i.1976, 1 ♀; 0–100 m, ii.1976, 1 ♂; 0–100 m, xii.1978, 1 ♂; 0–100 m, iii.1980, 1 ♂, 1 ♀; 0–100 m, i.1981, 1 ♂, 1 ♀; all N.H.L. Krauss. Epi: Vaemali, 80–150 m, 11–18.viii.1967, 1 ♀; 8.viii.1967, Malaise trap, 8 ♀; 12.viii.1967, Malaise trap, 1 ♀; 16–21.viii.1967, Malaise trap, 1 ♂, 1 ♀; 100–150 m, 6–10.viii.1967, 1 ♂, 3 ♀; 150 m, 9–20.viii.1967, Malaise trap, 1 ♂, 5 ♀; all J. & M. Sedlacek. Erromango: Ipota, 0–100 m, iii.1970, 2 ♂, 1 ♀, N.H.L. Krauss. Espiritu Santo: Luganville, 29–30.viii.1958, 1 ♂, B. Malkin; SW, Namatasopa, 300 m, light trap, 1–2.ix.1957, 1 ♂, J.L. Gressitt; SW, Tasmalum, 3 m, ex fresh human excrement, 4.ix.1957, 4 ♀, J.L. Gressitt. Maewo: Kerepei, 0–200 m, viii.1983, 1 ♂, 1 ♀, N.H.L. Krauss. Malekula: Lakatoro, Malaise trap, 29.ix.1967, 1 ♀, J. & M. Sedlacek; Lakatoro, 0–200 m, ii.1973, 3 ♀, N.H.L. Krauss; N. Lakatoro, 22–30.ix.1967, 13 ♀, J. & M. Sedlacek. Pentecost: 14.iii.1964, 2 ♀, R. Straatman; 24.iii.1964, 4 ♀, R. Straatman. Tanna: Lenakel, 0–150 m, iii.1970, 1 ♀, N.H.L. Krauss.

Comments. A widespread and common species first recorded from Vanuatu by Pont (1989). A few specimens lack the dorsal preapical seta on hind femur, but the material is too small and its condition too poor to determine whether there is a second species of the subgenus Acritochaeta on Vanuatu.

Distribution. American Samoa, Australia (NSW, NT, Qld, WA), Belau, Bonin Is, Easter Island, Fiji, French Polynesia, Guam, Hawai‘ian Is, Indonesia (West Papua, Maluku), Johnston Atoll, Kiribati, Marcus I., Marshall Is, Micronesia, New Caledonia (New Caledonia), Niue, Northern Marianas, Palmyra Atoll, PNG (Bismarck Arch., PNG), Solomon Is, Tonga, Vanuatu, Volcano I., Wake I., Western Samoa; pantropical.