Asiobaccha doesburgi Mengual sp. nov.

(Figure 5c, d, f)

Description

Male: Head. Face with distinct facial tubercle, yellow, darker basolaterally along eye margin, pale pilose except dark pilose dorsolaterally, white-silver pollinose except tubercle shiny (Figure 5f); gena yellow; lunule yellow, shiny; frons slightly protruded forward, black, dark pilose, pale pollinose laterally and dorsally, shiny basomedially dorsad to lunule; vertical triangle narrow, black, slightly pollinose; antenna bright yellow, black pilose; arista brown, bare; eye bare; occiput black, white-silver pollinose, entirely yellow pilose.

Thorax. Scutum dark, medially brown pollinose, with short and scarce pale pile; mesonotal fringe well-defined on anterior part of scutum, with yellow pile; postpronotum paler, somewhat yellow, yellow pollinose; notopleuron tawny, yellow pollinose; scutellum yellow, yellow pilose, subscutellar fringe absent (Figure 5c, d). Pleuron brown, dark brown, except anepisternum yellow (brown between anterior and posterior anepisternum), katepisternum with dorsal, broad yellow macula and katatergum paler; pale pilose, densely white pollinose; anterior anepimeron pilose dorsally; metaepisternum pilose ventrad to spiracle; metasternum bare; calypter small, reduced, yellow; plumula small, pale; halter pedicel yellow, capitulum dark; posterior spiracular fringes yellow. Wing: alula triangular, broader than costal cell apically, bare with some microtrichia basally. Wing membrane hyaline apically and basally, but clearly infuscated (dark brown) medially; stigma dark brown and costal cell brownish; extensively microtrichose, except cell R bare on basal 1/2, cell BM bare on basal 1/2 – 3/4, costal cell bare very basally, and cell CuP and anal lobe bare on basal 1/5. Legs: pro- and mesoleg yellow except black coxae; metacoxa and metatrochanter black, metafemur yellow with diffuse subapical dark annulus, metatibia black somewhat paler basally, metabasitarsomere black except yellow on apical 1/10 or less, metatarsi 2 – 5 yellow.

Abdomen. Petiolate, unmargined, mainly black pilose except tergum 1 pale pilose. Tergum 1 yellow with a posterior narrow brown fascia; tergum 2 yellow with a medial, diffuse brown macula and brown on posterior 1/5; tergum 3 black with a basal, broad yellow fascia (about 1/2 of tergum length) reaching anterior margin; tergum 4 black with grey pollinose fascia on basal 1/3; other terga black (Figure 5c, d); sterna 1 – 2 yellow, sterna 4 – 7 black, and sternum 3 yellow on anterior 1/2 and black on posterior 1/2.

Female. Similar to male except for normal sexual dimorphism and as follows: frons pollinose, ocellar triangle shiny contrasting with frons.

Variation. Some specimens have a medial, small dark macula on the yellow fascia of tergum 3, on anterior margin. Paler specimens have yellow halter and basal 1/2 of metatibia pale.

Length (N = 4). Body, 13.0 – 15.0 (14.3) mm; wing, 11.8 – 13.5 (12.5) mm.

Geographical distribution

Species known from Papua New Guinea.

Etymology

This species is named after Pieter H. van Doesburg, Sr. (1892 – 1971) in his honour to acknowledge his work on Syrphidae, especially on this genus. The name is to be treated as a noun in the genitive case.

Differential diagnosis

Species with a broad alula, mostly bare, terga 1 and 2 mainly yellow, tergum 4 black, mesonotal fringe present and infuscated wing. Similar to A. virtuosa and A. nubilipennis, but A. doesburgi has tergum 1 yellow, tergum 4 black, and cell R bare basally.

Type locality

Papua New Guinea: Morobe Province, Bulolo District, Manki Logging Area, 70°20 ′ S, 146°42 ′ E.

Material examined

Type material. Holotype, male, deposited in The Natural History Museum, formerly British Museum (Natural History) (London, United Kingdom) and labelled: ‘PAPUA NEW GUINEA: // Bulolo, // Manki Logging Area // 20.v.1983 // H. Roberts’ [handwritten] ‘ Allobaccha ♂ //? nubilipennis Austen // N.P. Wyatt det. 1983 ’, ‘ 2I29 ’, ‘ HOLOTYPE // Asiobaccha // doesburgi // des. X. Mengual 2014’ [red] (specimen photographed). Paratypes: PAPUA NEW GUINEA: Morobe Prov., NE Wau, 1200 m, 4 February 1970, J. Sedlacek [1♂, BPBM];..., NE Wau, 1100 – 1200 m, June 1968, N.L.H. Krauss [1♀, ZFMK, ZFMKDIP 00011911];..., Kaisenik, 16 August 1978, on Pinus patula, H. Roberts [1♀, BMNH]; Central Prov., Tapini, 1100 m, November 1968, N.L. H. Krauss [1♀, BPBM]; Chimbu Prov., Wahgi Valley, Kerowagi area, 1700 m, 24 June 1957, D. Elmo Hardy [1♀, ZFMK, ZFMKDIP 00011909].