Asiobaccha doesburgi Mengual

Mengual, Ximo, 2016, A taxonomic revision of the genus Asiobaccha Violovitsh (Diptera: Syrphidae), Journal of Natural History 50, pp. 2585-2645 : 2602-2603

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].

Figures

Figure 5. Asiobaccha bimaculata (Keiser). a–b, e, holotype ♀. (a) Dorsal view; (b) lateral view; (e) frontal view. Asiobaccha doesburgi Mengual sp. nov. c–d, f, holotype ♂. (c) Dorsal view; (d) lateral view; (f) frontal view. Scale bars: a–d = 2 mm; e, f = 1 mm.