Citrogramma schlingeri, 2012

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 : 161-162

CITROGRAMMA SCHLINGERI THOMPSON SP. NOV.

Description

Male: Head: Face with low facial tubercle, gradually sloping dorsally, more abrupt ventrally, with oral apex slightly more prominent than antennal base, entirely yellow, black pilose; gena yellow, dark pilose; lunule yellow; holoptic; frontal triangle yellow with very narrow posterior black vitta on eye margin, black pilose; vertical triangle black, as long as eye contiguity, black pilose, golden pollinose ( Fig. 50 ); ocelli reddish; antenna orangish brown, black pilose on scape and pedicel; basoflagellomere orangish, dark dorsally; arista brown; occiput black, silver pollinose, pale pilose on ventral half, yellow pilose medially and dark pilose on dorsal third.

Thorax: Scutum black with dorsomedial area almost uniformly grey pollinose without brightness, with a lateral yellow vitta, black pilose except notopleuron yellowish pilose on anterior third, densely black pilose on ventral notopleuron and supra-alar area; postpronotum yellow; notopleuron yellow continuing until scutellum, with postalar callus entirely yellow, black pilose; scutellum yellow with dorsomedial broad round brown macula, black pilose, with sparse incomplete subscutellar fringe with black hairs. Pleuron mostly yellow, except posterior anepisternum black on anterior third, katepisternum black with dorsal yellow macula, meron black, posterior anepimeron black, katatergum black posteriorly, grey pollinose ventrally, mainly yellow pilose, except anterior anepimeron with little black hairs and anepisternum black pilose on posterodorsal quadrant; metasternum pilose; calypter yellow basally and very blackened distally, with long black hairs on margin; plumula yellow, long, about twice as long as subalare; halter orangish; spiracular fringes yellow.

Wing: Wing membrane brown, costal cell darker, entirely microtrichose. Alula microtrichose, broad, slightly broader than cell BM.

Legs: Coxa and trochanter orangish brown, black and yellow pilose; femur, tibia and tarsus black, except pro- and mesofemur yellowish distally, and pro- and mesotibia yellowish basally; black pilose; tibia orange-yellow pollinose.

Abdomen: Figure 51 . Parallel-sided, terga 3 and 4 margined. Dorsum mainly black, black pilose dorsally and laterally except tergum 1 yellow pilose laterally and tergum 2 yellow pilose laterally on anterobasal quarter; tergum 1 black, yellow laterally; tergum 2 black with two mesolateral yellow maculae, laterally extended forward to anterolateral tergal margin and pointed mesomedially, yellow lateral margin on anterior quarter; terga 3 and 4 black with broad, about third of tergum length, medially narrowed yellow fascia, not reaching lateral margin; tergum 5 black with narrower yellow fascia constricted medially; sterna yellow, yellow pilose; male genitalia as in Figure 141 .

Female: See description of females under C. schlingeri species group.

Variation: Species variable. Some specimens with pro- and mesotibia lighter, dark brown. Pleura mostly yellow pilose with black hairs on posterior anepisternum, but some individuals with black hairs on anepimeron too. The coloration of anepimeron is variable: in some specimens, like the holotype, anepimeron is yellow with a black macula on posterior section; other specimens have several small black maculae on anepimeron; and at the other extreme, there are specimens with anepimeron black except dorsomedial section yellow.

The specimen from Goilala has the black macula on posterior anepisternum not well defined and it can look yellowish.

Length (N = 2): Body, 8.0–10.2 (9.1) mm; wing, 7.2–9.4 (8.4) mm.

Geographical distribution: New Guinea.

Etymology: This new species is named after Evert Irving Schlinger in his honour. Schlinger has worked mainly on the family Acroceridae (Diptera) and has described several genera and dozens of new species. I am particularly indebted to Evert Schlinger and his foundation for the economic support during my postdoctoral studies at the National Museum of Natural History (Smithsonian Institution). Species epithet to be treated as a noun in apposition.

Differential diagnosis: Species with entirely yellow face, gena yellow, broad frontal triangle (angle more than 90°) with a narrow black fascia on eye margin, costal cell darker than rest of wing membrane (except stigma), brown macula on scutellum and legs almost entirely black. Species difficult to distinguish from others in its group, like C. distinctum or C. triton , and it can only be separated by male genitalia. Citrogramma pintada and C. pinyton are very similar and they probably belong to the same species group, but these have anepisternum yellow.

Remarks: Originally, Thompson diagnosed this new species during his stay at AMNH many years ago. At the very beginning of this revision, Chris provided two undescribed species, a male of C. schlingeri and another male of C. distinctum , clearly differentiated by the male genitalia and the colour of the anepimeron. After the study of BPBM material, only the male genitalia were noted as different and a third species, C. triton , was diagnosed in this species group. Females are very difficult to distinguish for each species based on male specimens. Only females of C. pintada and C. pinyton could be separated by the coloration of costal cell. Thus, females of this species group are described together.

Holotype male deposited in the Bernice P. Bishop Museum ( Honolulu , Hawaii, USA) and labelled: ‘ NEW GUINEA: NE:/ Mt Wilhelm, 2550–2700 m,/ 10.VIII.1969 ’ ‘ J.L. Gressitt & Mena,/ Collectors /

BISHOP MUSEUM’ ‘ HOLOTYPE / Citrogramma / schlingeri /det. X. Mengual 20 09 ’ [red, second and third lines handwritten].

Type locality: Papua New Guinea: (Simbu, Western Highlands and Madang provinces intersection), Mount Wilhelm , 2550–2700 m, 5°48′00′′S, 145°02′00′′E .

Material examined: Type material. Holotype, as above. Paratypes. PAPUA NEW GUINEA: Eastern Highlands District, no. 6, Pengagl Camp, east slopes Mt Wilhelm , 2770 m, 22–24.vii.1959, L. J. Brass [1♂, AMNH]; Neth. Ind. –American New Guinea Exped., Top Camp 2100 m, 25.i.1939, L.J. Toxopeus [1♂, RMNH]; NE: Ialibu, 2650–2900 m, J.L. Gressitt [1♂, BPBM]; Kepilam, J. & M. Sedlacek [1♂, BPBM]; Owen Stanley Range, Goilala: Bome, 1950 m, 16–30.iv.1958, W.W. Brandt [1♂, BPBM] .

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.

Figures 51–62. 51–52, Citrogramma schlingeri: 51, dorsal view of male abdomen; 52, dorsal view of female abdomen. 53, Citrogramma flavigenum, dorsal view of male abdomen. 54–55, Citrogramma sp. 1: 54, dorsal view of female abdomen; 55, wing. 56, C. flavigenum, dorsal view of male head. 57–60, Citrogramma luteopleurum: 57, dorsal view of female head; 58, dorsal view of male head and lateral view of scutum; 59, dorsal view of male abdomen; 60, dorsal view of female abdomen. 61–62, Citrogramma pintada: 61, dorsal view of male abdomen; 62, dorsal view of female abdomen.

Figures 140–144. Male genitalia. 140, Citrogramma bicornutum (from Vockeroth, 1969): a, left lateral view; b, superior lobe, lateral, outline only; c, sternum 9, superior lobes and aedeagal base, ventral view; d, right surstylus, lateral view. 141, Citrogramma schlingeri, left lateral view. 142, Citrogramma distinctum, left lateral view. 143, Citrogramma triton, left lateral view. 144, Citrogramma frederici, left lateral view.