Citrogramma quadricornutum, VOCKEROTH, 1969

Mengual, Ximo, 2012, The flower fly genus Citrogramma Vockeroth (Diptera: Syrphidae): illustrated revision with descriptions of new species, Zoological Journal of the Linnean Society 164 (1), pp. 99-172 : 159

CITROGRAMMA QUADRICORNUTUM VOCKEROTH, 1969

Citrogramma quadricornutum Vockeroth, 1969: 96 . Holotype: ♂, BPBM, by original designation. Type locality: Papua New Guinea: Wau. Vockeroth, 1969: 96, fig. 95; Thompson & Vockeroth, 1989: 442; Wyatt, 1991: 155, 157.

Description

Male: See original description in Vockeroth (1969: 96–98).

Female: Very similar to male: face yellow, medially shiny and laterally white pollinose; gena yellow, with a black macula on genal groove; frons yellow with medial broad black vitta narrowing dorsally, with bluish metallic iridescence, not reaching ocellar triangle, black laterally on eye margin on dorsal half, forming a narrow inverted V-shaped yellow macula; antenna orange, basoflagellomere dark dorsally; lunule yellow. Pleuron mostly yellow, except katepisternum black with dorsal yellow macula, posterior anepisternum black on anterior half, meron black, anterior anepimeron black, and katatergum black posteriorly. Metasternum bare. Scutellum yellow with dorsal broad dark macula reaching anterior margin. Coxa and trochanter yellow; pro- and mesolegs yellow except tarsi dark; metaleg black. Same scutum and abdominal pattern as in male, with yellow fasciae narrower and two triangular yellow maculae joined medially on tergum 2 ( Fig. 43 ). Abdomen a bit broader.

Geographical distribution: New Guinea.

Diagnosis: Very distinct species with face entirely yellow and large male genitalia. Citrogramma quadricornutum is the only species of this genus with metasternum bare, and it also has scutellum with a broad defined black macula, scutum with two metallic bluish vittae, and abdominal terga 2, 3, 4, and 5 with posterior bluish metallic dark vittae ( Figs 42, 43 ). In general, C. quadricornutum is a small species with the most extensive bluish metallic areas in its body, on frons, scutum, pleuron, and abdomen.

Remarks: Vockeroth (1969) did not describe the female of this species. A short description of the only female studied, deposited in the BMNH, is here provided.

Holotype male deposited in the Bernice P. Bishop Museum ( Honolulu , Hawaii, USA) and labelled:

‘NEW GUINEA: NE/Wau, 1250 m / 10.V.1965 ’ ‘J. Sedlacek/Collector/BISHOP’ ‘ HOLOTYPE / Citrogramma / quadricornutum / Vockeroth ’ [red, handwritten except first line].

Type locality: Papua New Guinea: Morobe Province, Bulolo District, Wau , 1250 m, 70°20′S, 146°42′E .

Material examined: Type material. Holotype, as above. Paratype. PAPUA NEW GUINEA: Morobe Province, Wau, 1400 m, 20.xii.1961, J. & J.H. Sedlacek [1♂, CNC]; (NE) 6 km W of Wau, Nami Creek , 1700 m, 10.vi.1962, J. Sedlacek [1♂, BPBM] .

Nontype material. PAPUA NEW GUINEA: NE, Wau , 1150 m, vi.1971, M. Sedlacek [1♂, BPBM];..., 13.vii.1971,... [1♂, BPBM]; Wau, Kulolo Creek, 10.vi.1983, H. Roberts [1♂ 1♀, BMNH] .

Figures

Figures 39–50. 39–40, Citrogramma solomonense: 39, dorsal view of male abdomen; 40, dorsal view of female abdomen. 41, Citrogramma hervebazini, dorsal view of female abdomen. 42–44, Citrogramma quadricornutum: 42, dorsal view of male abdomen; 43, dorsal view of female abdomen; 44, dorsal view of male scutum and scutellum. 45, Citrogramma fumipenne, dorsal view of male abdomen. 46–49. Citrogramma luteifrons: 46, dorsal view of female head; 47, dorsal view of male abdomen; 48, lateral view of male pleuron and head; 49, dorsal view of female abdomen. 50, Citrogramma schlingeri, dorsal view of male head.