Asiobaccha samoaensis Mengual
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|Asiobaccha samoaensis Mengual|
Asiobaccha samoaensis Mengual sp. nov.
( Figure 9a, b, e View Figure 9 )
Baccha praefica of Hull 1929: 194.
Episyrphus (Asiobaccha) praefica of Thompson and Vockeroth 1989: 443 (in part, citation from Samoa).
Male: Head. Face with distinct round facial tubercle, black, black pilose, white-silver pollinose laterally, shiny medially; gena black; lunule black, shiny; frons slightly protruded forward, black, black pilose, dark brown pollinose posteriorly; vertical triangle narrow, isosceles, with the ocelli on the anterior half, black, black pilose; antenna yellow, basoflagellomere brown dorsally, black pilose; arista brown, bare; eye bare, holoptic; occiput black, grey-silver pollinose, pale pilose on ventral 3/4 and dark pilose on dorsal 1/4 ( Figure 9e View Figure 9 ).
Thorax. Scutum black with purple iridescence and partly brown pollinose, with short, black pile; mesonotal fringe or collar well-defined on anterior part of scutum, with pale pile; postpronotum black, bare; notopleuron black, pale pilose; scutellum black, brown pollinose on anterior margin, with short, black pile, subscutellar fringe with long, pale pile ( Figure 9a, b View Figure 9 ). Pleuron black, white pollinose on dorsal katepisternum and posterior anepisternum; anterior anepisternum yellow pilose on posterodorsal quarter, posterior anepisternum and anepimeron pale pilose; metaepisternum with short, dark pile ventrad to spiracle; metasternum bare; calypter small, reduced, yellow; plumula small, pale; halter dark brown to black; posterior spiracular fringes pale. Wing: alula broad, as broad as or broader than cell BM, microtrichose. Wing membrane infuscated, brown; entirely microtrichose. Legs: dark brown to black.
Abdomen. Parallel sided, slightly petiolate, unmargined; dark with bluish-purple iridescence without pollinosity, or small, black pollinose maculae medially; terga 1 and 2 pale pilose, and terga 4 – 6 black pilose; tergum 3 pale pilose anteriorly and black pilose posteriorly ( Figure 9a, b View Figure 9 ); sterna black. Male genitalia dark.
Female. Similar to male except for normal sexual dimorphism and as follows: frons black, shiny, white pollinose only lateroventrally; occiput entirely pale pilose.
Variation. Some specimens may have the face, under the white pollinose laterals, a yellow background. Lighter individuals have basal part of pro- and mesotibiae yellow and postalar callus light brown.
Length (N = 5). Body, 10.0 – 14.5 (12.5) mm; wing, 8.0 – 10.0 (9.4) mm.
Species known only from Samoan Islands.
The specific epithet is derived from the country ’ s name where the species is found, Samoa, and the Latin suffix - ensis denoting place, locality, country, or belonging to, pertaining to ( Brown 1956, p. 45, 303). Species epithet is to be treated as adjective.
This taxon has the face, the scutellum and the abdomen dark, with purple shine, and it presents a broad alula. It is very similar to A. praefica , both with the metatarsi dark brown or black, but they can be distinguished by the microtrichosity of the basal cells: A. praefica has the cell BM bare basally, and A. samoaensis has the wing entirely microtrichose.
American Samoa: Eastern district , Tutuila island, N .P. American Samoa, Mt. ‘ Alava, 300 – 480 m, 14°15 ʹ 53 ʹ ’ S, 170°41 ʹ 17 ʹ ’ W.
Type material. Holotype, male, deposited in the Bernice P. Bishop Museum (Honolulu, Hawaii, USA) and labelled: ‘ SAMOA: Tutuila, // Mt. Alava, 300 – // 480 m, 9.III.1971 ’ ‘ N.L.H. Krauss // Collector // BISHOP MUSEUM ’ ‘ HOLOTYPE // Asiobaccha // samoaensis // des. X. Mengual 2014’ [red] (specimen photographed). Paratypes: AMERICAN SAMOA: Tutuila island, N.P. American Samoa, Mt. ‘ Alava, 300 – 480 m, 9 March 1971, N.L.H. Krauss [1♂, BPBM; 1♂, ZFMK, ZFMKDIP 00011919]; Tutuila island, 9 August 1957, W.R. Kellen [1♀, BPBM];..., Pago Pago, 16 April 1924, E.H. Bryan Jr. [1♂, CNC];..., Pago Pago, 21 July 1925, G.P. Wilder [1sp., BPBM];..., Pago Pago, 14 December 1925, P.A. Buxton and G.H. Hopkins [1♀, BPBM];..., Malaota, 10 September 1953, C.P. Hoyt, sweeping ferns [1♂, ZFMK, ZFMKDIP 00011930]; Manu ’ a district, Tau island, Tavalogi Ridge, 165 m, 16 – 19 February 1965, G.A. Samuelson, Malaise trap [2♂ 2♀, BPBM; 1♂ 1♀, ZFMK, ZFMKDIP 00011943, 00011940]. SAMOA: Tuamasaga district, Upolu island, Tuaefu, 16 September 1923, Swezey and Wilder [1♀, BPBM; 1♀, ZFMK, ZFMKDIP 00011938];..., Afiamalu, 19 June 1940, 2100 ft., E.C. Zimmerman, beating [1♀, BPBM];..., Malololelei, 2000 ft., 18 April 1924, P.A. Buxton and G.H. Hopkins [1♂, BPBM];..., 17 June 1924, P.A. Buxton and G.H. Hopkins [1♀, CNC];..., 21 June 1924, J.S. Armstrong [1♀, BMNH];..., 22 June 1924, J.S. Armstrong [1♀, CNC];..., 30 June 1924, J.S. Armstrong [1♀, BPBM]; Palauli district, Savai ’ i island, Sala ’ ilua, 19 May 1924, E.H. Bryan Jr. [1♀, BPBM];..., 21 May 1924, E.H. Bryan Jr. [1♀, BMNH];..., 22 May 1924, E.H. Bryan Jr. [1♂, BMNH];..., Safune, lower forest, 1000 – 2000 ft., 11 May 1924, E.H. Bryan Jr. [1♀, RMNH];..., Asau, 200 m, 3 January 1969, B. Hocking [1♀, ZFMK, ZFMKDIP 00011941].
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