Citrogramma luteopleurum, 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 : 148-149

CITROGRAMMA LUTEOPLEURUM MENGUAL SP. NOV.

Citrogramma luteifrons of Wyatt, 1991: 157, 165.

Description

Male: Head: Face with facial tubercle, gradually sloping dorsally, more abrupt ventrally, entirely yellow, mainly yellow pilose, dark pilose dorsally and laterally, white pollinose laterally; gena yellow with a brown macula ventrad to eye, mainly yellow pilose with little dark hairs on macula, white pollinose posteriorly; holoptic; lunule orange; frontal triangle yellow with a medial triangular orange macula pointed posteriorly, black pilose; vertical triangle black, black pilose ( Fig. 58 ); ocelli brownish; antenna brownish, black pilose on scape and pedicel; basoflagellomere dark dorsally; arista brown; occiput black, mainly silver pollinose, golden pollinose dorsally, yellowish-white pilose on ventral two thirds, black pilose on dorsal third.

Thorax: Scutum black with dorsomedial area almost uniformly grey pollinose with some metallic iridescence, with lateral yellow vitta and sublateral narrow matte black vitta, black and yellow pilose dorsally, mainly yellow pilose laterally except postalar callus entirely black pilose and some black hairs dorsally after transverse suture, densely yellow pilose on lateral notopleuron and supra-alar area; postpronotum yellow; notopleuron yellow continuing until scutellum; scutellum yellow with dorsomedial broad brownish macula reaching posterior margin, black pilose, with complete subscutellar fringe of black hairs. Pleuron mostly yellow ( Fig. 58 ), except katepisternum black with a dorsal large yellow macula, meron black and anepimeron yellow with a small black macula on posterior section, entirely yellow pilose; metasternum pilose; calypter yellow, blackened basally and distally, with yellow and black hairs on margin; plumula yellow; halter yellow; spiracular fringes yellow.

Wing: Wing membrane brownish, lighter on posterior margin, entirely microtrichose. Alula microtrichose, broad, broader than costal cell, and slightly narrower than cell BM.

Legs: Coxa and trochanter yellow, yellow pilose; pro- and mesofemur and tibia yellow; pro- and mesotarsus dark yellow, clearly different from tibia; metafemur black, yellow, or yellowish on basal half; tibiae and tarsi black; femur, tibia, and tarsus mainly black pilose.

Abdomen: Figure 59 . Parallel-sided, tergum 4 slightly margined. Dorsum mainly matte black, except terga 2, 3, and 4 each with a posterior shiny black fascia, black pilose dorsally and laterally except tergum 1 yellow pilose laterally and tergum 2 yellow pilose laterally on anterobasal third; tergum 1 black, yellow laterally; tergum 2 black with two mesolateral subtriangular yellow maculae, laterally extending forward to anterolateral tergal margin (like ‘golf club’- shaped spots), yellow lateral margin on anterior half; terga 3 and 4 black with broad slightly sinuate yellow fascia on anterior half of tergum, about two fifths of tergum length, not reaching lateral margin; tergum 5 black with yellow fascia, widening laterally; sterna yellow, yellow pilose with black hairs posteriorly; genital segments yellowish; male genitalia brownish, as in Figures 127 and 130 .

Female: Similar to male except for normal sexual dimorphism and as follows: face yellow entirely pilose; frons yellow, orangish medially dorsad to lunule, with a black vitta on lateral margin from ocellar triangle to half distance between anterior ocellus and antennal base; abdominal tergum 2 with two yellow maculae joined medially forming a fascia; terga 3, 4, and 5 with a straight yellow fascia not reaching lateral margin ( Fig. 60 ).

Variation: Coloration of coxa and trochanter is variable. Some individuals have a yellowish ring on metatibia, difficult to see. Some specimens have a yellow fascia on tergum 4 that only the anterior portion of the fascia reaches lateral margins, but mostly not. Few specimens have tergum 5 with a yellow fascia little widening laterally. The scutellar brown macula is very clear in most of the specimens, but some individuals can look like they have yellow scutellum. The lateral matte black vitta of scutum may be indistinguishable in some specimens. Some individuals present a dark yellow area on anterior half of posterior anepisternum as a result of the drying process. Although it should not create confusion, there is a note under couplet 39 explaining the differences in a possible case of misinterpretation.

Length (N = 5): Body, 10.0–10.8 (10.5) mm; wing, 8.5– 9.1 (8.8) mm.

Geographical distribution: New Guinea.

Etymology: The specific epithet is derived from the Latin luteus meaning yellow, and the Greek pleura meaning side ( Brown, 1956: 500, 618), and refers to the large yellow area on pleuron of this species. Species epithet to be treated as an adjective.

Differential diagnosis: Citrogramma luteopleurum belongs to a species group where specimens present a yellow fascia on terga 3 and 4 not reaching lateral margins. The species are very difficult to differentiate amongst the group, including C. pintada and C. schlingeri . Citrogramma luteopleurum is similar to C. pintada , but with frontal triangle entirely yellow and lunule yellow; females of C. luteopleurum have frons medially yellow.

Remarks: The male collected by H. Roberts (BMNH) was identified and published as C. luteifrons by Wyatt (1991), but it has posterior anepisternum yellow (slightly dark yellow anteroventrally) and anepimeron yellow with posterior anepimeron black very dorsally; thus not matching the original description of the species. Moreover, this BMNH male has abdominal tergum 3 with a yellow fascia that does not reach lateral margins. This male is here designated as the holotype of Citrogramma luteopleurum Mengual sp. nov.

Holotype male deposited in The Natural History Museum, formerly British Museum (Natural History) (London, UK) and labelled: ‘ PAPUA NEW GUINEA: / Kulolo Creek / 9–vi–1983 / H. Roberts ’ [handwritten] ‘2128’ ‘ Citrogramma sp. ♂ /nr. clarum Herve – Baz. / det. N.P. Wyatt 19 83 ’ ‘ Citrogramma / luteifrons (de Meijere) /det. N.P. Wyatt 19 89 ’ ‘ HOLOTYPE / Citrogramma / luteopleurum /det. X. Mengual 20 09 ’ [red, second and third lines handwritten].

Type locality: Papua New Guinea: Morobe Province, Wau, Kulolo Creek , 70°20′S, 146°42′E .

Material examined: Type material. Holotype, as above. Paratypes. PAPUA NEW GUINEA: (NE) Morobe Province, Wau, 1500 m, 24.ix.1961, J. Sedlacek [1♀, BPBM];..., 1200 m, 10.v.1963, J. Sedlacek [1♀, BPBM];..., Nakata Ridge, 4700 ft, 11.vi.1968, J.W. Boyes [2♂ 2♀, CNC]; Owen Stanley Range, Goilala, Loloipa. 1–15.ii.1958, W.W. Brandt [1♂ 2♀, BPBM]; Wau, 1250 m, 23.viii.1965, Malaise trap, J. & M. Sedlacek [1♂, BPBM]; Tapini, 1100 m, 7.xi.1968, N.L.H. Krauss [1♂, BPBM]; (NE) 6 km W of Wau, Nami Creek , 1700 m, 15.vi.1962, Malaise trap, J. Sedlacek [1♀, BPBM];..., 10.vi.1962,... [1♀, BPBM]; NE Ialibu, 8–14.i.1968, 2900 m, Gressitt – Maa [1♀, BPBM] .

Figures

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 122–130. 122–123, Citrogramma frederici: 122, frontal view of female head; 123, dorsal view of female abdomen. 124–126, Citrogramma notiale species group: 124, lateral view of puparium; 125, dorsal view of puparium; 126, posterior view of posterior breathing tube and spiracular openings (detail). 127, Citrogramma citrinum, left lateral view of male genitalia. 128–129, Citrogramma henryi: 128, left lateral view of male genitalia; 129, tergum 9 and surstyli, dorsal view. 130, C. henryi (from Vockeroth, 1969 as C. citrinum): a, left lateral view; b, superior lobe, lateral, outline only; c, sternum 9, superior lobes and aedeagal base, ventral view.