Citrogramma amarilla, 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 : 106-128

CITROGRAMMA AMARILLA MENGUAL SP. NOV.

Olbiosyrphus clarum of Hervé-Bazin, 1923a, b (in part).

Syrphus difficilis of Curran, 1928 (in part).

Syrphus clarus of Curran, 1931b (in part).

Description

Male: Head: Face with facial tubercle, gradually sloping dorsally, more abrupt ventrally, entirely yellow, yellow pilose, dark brown pilose dorsolaterally; gena yellow, yellow pilose posteriorly with brown hairs on genal suture, white pollinose posteriorly; holoptic; lunule yellow; frontal triangle yellow, dark brown pilose; vertical triangle black, black pilose; ocelli reddish; antenna orangish, black pilose on scape and pedicel; basoflagellomere dark dorsally and distally; arista dark; occiput black, silver pollinose, white pilose on ventral half, yellow pilose on dorsal half.

–. Terga 3 and 4 with broader fascia, about half of tergum length, strongly emarginate posteriorly and very narrow laterally, lateral yellow margin being narrower than half fascia length ( Fig. 116 ) (Java, Sumatra, Hainan)........... ................................................................................................................. C. gedehanum (de Meijere)

51. Lunule dark, brown to black; frons yellow with medial triangular black macula reaching black area of ocellar triangle or not ( Fig. 109 ). Posterior anepimeron mostly black ( Fig. 114 ) ................................................................ 52

–. Lunule yellow; frons yellow, slightly darker medially ( Fig. 107 ). Posterior anepimeron yellow ( Fig. 110 ) (Borneo).. ..................................................................................................................... C. fascipleurum (Curran)

52. Occiput dark/black pilose on dorsal third (Malay peninsula, Borneo).................................. C. difficile (Curran)

–. Occiput yellow pilose on dorsal third (Java, Sumatra, Hainan)................................ C. gedehanum (de Meijere)

Thorax: Scutum blackish brown with dorsomedial area uniformly bluish grey pollinose with some metallic iridescence, with lateral broad yellow vitta, yellow pilose with black hairs on posterior half and on postalar callus, with two or three black hairs on notopleuron; postpronotum yellow; notopleuron yellow continuing to scutellum, with postalar callus entirely yellow; scutellum yellow, black pilose, subscutellar fringe complete with brown hairs. Pleuron mostly yellow, except katepisternum black ventrally and meron dark, entirely yellow pilose; metasternum pilose; calypter yellow, brownish dorsally with long yellow hairs and short black hairs on margin; plumula yellow; halter yellow; spiracular fringes yellow.

Wing: Wing membrane hyaline, entirely microtrichose. Alula microtrichose, broad, broader than cell BM.

Legs: Coxa and trochanter yellow, yellow pilose; pro- and mesofemur yellow, mainly black pilose, yellow pilose basally; pro- and mesotibia yellow, black pilose; pro- and mesotarsus brown; metafemur yellow on basal half to two thirds, brown/dark on distal third to half; metatibia brown with medial yellow annulus; metatarsus dark brown, black pilose.

Abdomen: Figure 67 . Parallel-sided, slightly oval, terga 3, 4, and 5 vaguely margined. Dorsum mainly black or dark brown, black pilose dorsally and laterally except tergum 1 yellow pilose laterally and tergum 2 yellow pilose laterally on anterobasal half and dorsally on yellow maculae; tergum 1 black, yellow laterally; tergum 2 black with two mesolateral round yellow maculae, extended forward laterally to anterolateral tergum margin (like ‘golf club’-shaped spots), yellow lateral margin on anterior half; terga 3 and 4 black with broad yellow fascia, about one third to two fifths of tergum length; tergum 5 black with very broad yellow fascia with posterior margin curved; sterna mainly yellow, yellow and black pilose; male genitalia small, as in Figures 127 and 130 .

Female: Similar to male except for normal sexual dimorphism and as follows: face entirely yellow pilose, frons yellow, dark brown pilose; ocellar triangle black; occiput yellow pilose. Scutum yellow pilose, with some black hairs posteriorly close to scutellum and on postalar callus, but lesser black hairs than in male; notopleuron yellow pilose; katepisternum grey pollinose on black ventral area. Pro- and mesobasitarsomere yellowish basally, brown distally; metafemur yellow on basal two thirds, dark brown on distal third; abdominal tergum 2 with two ‘golf club’-shaped yellow maculae joined medially forming a yellow fascia but of different shape than those on terga 3 and 4; tergum 4 with yellow fascia broader at lateral margin; tergum 5 with yellow lateral margin on basal four fifths ( Fig. 68 ).

Variation: In all specimens the yellow annulus of the metatibia is difficult to see because most of them have brownish metatibia, so there is little contrast. Paratype male from Philippines has abdomen compressed anteroposteriorly; thus, abdominal characters are difficult to see but it seems that tergum 5 has two triangular yellow maculae instead of a yellow fascia.

Females have small differences amongst them. Some specimens have a few black hairs on postalar callus but others do not. The most variant female is the one from Pahang Province , previously a paratype of C. difficile . Its frons matches the description but it has a very small black fascia posteriorly on lateral margin. Consequently it was not included as a paratype. The other male from India was not included in the type series because its head is lost .

Length (N = 4): Body, 9.0–10.1 (9.7) mm; wing, 7.8–8.9 (8.3) mm.

Geographical distribution: India, Nepal, Java, Philippines, Thailand, Laos, Hainan.

Etymology: The specific epithet is derived from the Spanish amarillo meaning yellow, and refers to the large yellow areas on thorax and face. Species epithet to be treated as a noun in apposition.

Differential diagnosis: Species very similar to the female of Citrogramma matsumurai . Citrogramma matsumurai is larger than C. amarilla (13.1 versus 9.9 mm) and its abdomen is more oval. Female of C. matsumurai has frons mainly yellow with posterior small black fascia joined to ocellar triangle ( Fig. 71 ); thus, black posterodorsal area of frons in C. matsumurai is larger (see Figs 66, 71 ).

Citrogramma amarilla is clearly related to C. clarum , but can be easily separated from this by wing being completely microtrichose and frons entirely yellow. Citrogramma clarum has wing partly bare basally (cell R bare on basoanterior half; see Fig. 124 ) and frons is black laterally on dorsal two fifths (narrow lateral vitta from ocellar triangle) ( Fig. 75 ).

Remarks: This species is clearly separable from C. clarum by its wing microtrichia and frons. During my study, I realised that the part of the identification key including C. matsumurai , C. amarilla , C. sp. B, and C. clarum could be a difficult species group, especially for females. Based on its widespread distribution, I did consider that this taxon defined here might group females from several species that look morphologically identical.

Holotype male deposited in the Nationaal Natuurhistorische Museum ‘Naturalis’ (Leiden, The Netherlands) and labelled: ‘S. India, Madras St./ Anamalai Hills/Kadamparai 3500 ft. / v–1963 /P. Susai Nathan’ ‘ Miogramma citrinum Brun. / ♂ /det. v. Doesburg’ [handwritten except third line] ‘ HOLOTYPE / Citrogramma / amarilla /det. X. Mengual 20 09 ’ [red, second and third lines handwritten].

Type locality: India: Tamil Nadu, Anaimalai Hills, Kadamparai , 1067 m, 10°22′N, 77°07.5′E .

Material examined: Type material. Holotype, as above. Paratypes. India: West Bengal, Darjeeling, Gopaldhara, Bw, 4720 ft, 10.vii.1911, H. Stevens [1♂, BMNH]; PHILIPPINES: Mountain Prov., Abatan, Buguias 60 km S of Bontoc, 1800–2000 m., 27.v.1964, H.M. Torrevillas [1♂, BPBM]; NEPAL: Ktmd., Goda- vari, 6000 ft, 13.viii.1967, Can. Nepal Exped. [1♀, CNC]; MALAYSIA: B.N. Borneo, Mt Kinabalu, Kenokok, 3300 ft, 24.iv.1929, H.M. Pendlebury [1♂, BMNH]; INDONESIA: Java ‘ Olbiosyrphus / clarum / H.- B. / cotype ’ [1♂, MNHN]; W Java, G. Tjimerang, Djampang Tengah, 600 m, iii.1937, M.E. Walsh [1♀, RMNH]; West Java, Wynkoopsbay, ii.1937, R. Mus. Hist. Nat. Belg. I.G.11.161 [1♀, IRSNB]; THAILAND: Khun Tan Mts., 4000 ft, v.1933, H.M. Smith [1♀, USNM]; Chiang Mai Province, Dai Chow Cheng, xi.1920, J.F. Rock [1♀, BPBM]; Chiang Mai Province, Doi Chiang Dao, 1150 m, 11.viii.1990, H. Bänziger [1♀, BMNH]; LAOS: Nam Long, 28.iv.1918, R. Vitalis de Salvaza ‘ Olbiosyrphus / clarum / Hervé-Bazin/cotype ’ [1♂, MNHN]; Dang He, 29.iv.1918, R. Vitalis de Salvaza ‘ Olbiosyrphus / clarum / Hervé-Bazin/cotype ’ [1♂, MNHN].

Nontype material. INDIA: Shillong, 15.vii.1961, CIBC-IS [1♂, BMNH]; MALAYSIA: Pahang, Cameron Highlands, Rhododendron Hill , 5200 ft, 21.vi.1923, H.M. Pendlebury ‘ Allotype / Syrphus / difficilis / Curran ’ [1♀, BMNH]; CHINA: Hainan, Wuzhishan City, Shuiman Town , 23–25.v.2007, Yi-Bi Ba & Jun-Tong Lang [2♀, SBSC] (Huo, unpubl. data).

Figures

Figures 112–121. 112–115, Citrogramma difficile: 112, dorsal view of male abdomen; 113, dorsal view of female abdomen; 114, dorsal view of female head and lateral view of pleuron; 115, lateral view of male head and pleuron. 116–118, Citrogramma gedehanum: 116, dorsal view of male abdomen; 117, dorsal view of female abdomen; 118, lateral view of male pleuron. 119–120, Citrogramma marissa: 119, dorsal view of male abdomen; 120, dorsal view of female abdomen. 121, Citrogramma pendleburyi, dorsal view of male abdomen.

Figures 100–111. 100, Citrogramma variscutatum, dorsal view of female abdomen. 101–102, Citrogramma currani: 101, dorsal view of male abdomen; 102, dorsal view of female abdomen. 103–106, Citrogramma wyatti: 103, dorsal view of male abdomen; 104, dorsal view of female abdomen; 105, anterodorsal view of male head; 106, dorsal view of female head. 107, Citrogramma fascipleurum, anterodorsal view of female head. 108–109, Citrogramma difficile: 108, frontal view of male head; 109, dorsal view of female head. 110, C. fascipleurum, lateral view of female pleuron and head. 111, C. difficile, dorsal view of head, scutum and scutellum.

Figures 63–75. 63, Citrogramma pintada, dorsal view of male head. 64–65, Citrogramma sp. 2: 64, lateral view of pleuron and dorsal view of female head; 65, dorsal view of female abdomen. 66–69, Citrogramma amarilla: 66, dorsal view of female head; 67, dorsal view of male abdomen; 68, dorsal view of female abdomen; 69, lateral view of female pleuron and head. 70–73, Citrogramma matsumurai: 70, dorsal view of male head; 71, dorsal view of female head; 72, dorsal view of male abdomen; 73, dorsal view of female abdomen. 74–75, Citrogramma clarum: 74, dorsal view of male head; 75, dorsal view of female head.

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.