Ceriana dirickxi Thompson

F. Christian Thompson, 2013, A new species, Ceriana dirickxi (Syrphidae, Eristalinae, Cerioidini), is described and illustrated from Zimbabwe. A key to the Afrotropical species of Ceriana is given., Mitteilungen der Schweizerischen Entomologischen Gesellschaft 86, pp. 145-150 : 146-148

Ceriana dirickxi Thompson , sp. nov.

Description. Female ( Figs 1- 2 ). Head. Reddish brown; face dark brown with broad yellow sublateral vitta and narrow reddish medial vitta, tubercle reddish; frons light reddish except small yellow macula lateral to junction of frons and face, sparsely white pilose; frontal prominence reddish brown; vertex reddish brown, sparsely white pilose; occiput reddish brown, white pollinose and pilose ventrally, more sparsely pollinose dorsally; gena yellow except reddish brown on medial 1 / 3, white pilose. Antenna dark reddish brown, black pilose; arista yellow; antennal ratio: 1.7 " 1.0:1.0: 1.3: 0.2; antennifer ratio: 3.3.

Thorax. Postpronotum reddish brown, pale pilose; scutum black on medial 2 / 3, reddish brown laterally, sparsely gray pollinose, short appressed yellow pilose, with some black pile medially; pleuron reddish brown except pectus darker; scutellum reddish brown, pale pilose; calypter white; halter yellow. Legs light reddish brown except coxae darker, pale pilose. Wing: tricolored, brownish orange yellow along anterior margin on basal 2 / 3 extending posteriorly to vein CuA on basal 1 / 5 and to vein Rs elsewhere, brownish black except hyaline on basomedial 1 / 3 and along posterior margin; vein R 4 + 5 sinuate but without a spur; completely microtrichose.

Abdomen. Dark without pale yellow maculae, short black pilose; l “ tergum black; 2 “ d tergum dark reddish brown except with black triangular area and based on posterior 2 / 3 with apex on anterior margin; 3111 tergum narrowly reddish brown on basolateral 1 / 4, black elsewhere; 41 h tergum black except for small reddish brown triangular area on apical 1 1 // / 1 4;g 5111 tergum reddish brown, pale pilose; sterna black, black appressed short pilose medially, yellow pilose laterally; abdominal segmental ratio. l. l.l. 0: l. 3: l. 7: 0.3; abdominal petiole ratio: l.0: 1.0:l. l

Length. Body, 13.6 mrn, wing, 12.0 mm.

Differential Diagnosis. Ceriana dirickxi runs to Ceriarıa ponti Thompson in the last key to Afrotropical cerioidines (Thompson 2013 a: 73), and is quite similar in stature to that species but is quite different in coloration. C. ponzi has a dark abdomen with a bright continuous yellow sublateral margin, whereas C. dirickxi has an unicolorous, brownish red to black abdomen. C cliríckxi was collected at the same locality and by the same collector as the only two known specimens of Ceriana dilatipes Brunetti. Hence , while one may think that these are only color variants of the same species, they are quite distinct: C. dilarípes has broad apical yellow fascia on 2 nd, 3 rd and 4 '“ terga, a yellow vitta on the laterotergum as well as a bare alula, whereas C. dirickxi lacks these yellow maculae and has a microtrichose alula.

Type Material. Holotype female pinned with the following labels: << SAW MILLS // S. Rhodesia // 10.12.1926 // R.H.R. Stevenson » [with a narrow black bor- der on label]; << NMSA-DIP / 44959 ;» and << Holotype // Ceriana // dirickxi // Thompson 2013 » [hand-written on orange card stock] deposited in National Museum of South Africa, Bloemfontein.

Type locality. Zimbabwe, Saw Mills , 19 ° 35 ’ S, 028° 12 ’E

Distribution. Zimbabwe.

Etymology. Traditionally cerioidine species are named after distinguished dipterists. So. I am delighted to name this distinctive species after my former colleague, Henri Dirickx (1928 04.23 — 2013.02 .05), who recently passed on. I am only sorry that I did not do this sooner. Henri was born in Belgium, Anvers [the original home of another flower fly worker, Marc De Meyer] and was trained as a civil engineer. Later he worked for the United Nations Economic Commission in Geneva and retired in 1988. In his retirement, he worked on Afrotropical flower flies. He published a detailed catalog of the species (Dirickx 1998), summarizing the prior work on these flies as well as revisions of various genera: Spheginobaccha (Dirickx 1995) , Melanostoma (Dirickx 2001) & Allobaccha (Dirickx 2010) . Also, he published a review of fossil flower flies (Dirickx 2009) and a couple of other papers, all of his papers on flower flies are listed in the reference section (Dirickx 1994, 2009; Dirickx et al. 1996; Dirickx & Obrecht 2007; Dirickx & Steffan 1992; Maibach et al. 1995). Finally, I and Martin Hauser are in the process of finishing a joint paper with him on Madagascar cerioidine flies. Unfortunately, he passed away too soon to do more.

Figures

Figs 1- 2

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