Research Article |
Corresponding author: Burgert S. Muller ( burgert.muller@nasmus.co.za ) Academic editor: Kirstin Williams
© 2019 Burgert S. Muller.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Muller BS (2019) A curious new Coenosia Meigen, 1826 (Diptera, Muscidae) from Mariepskop, Mpumalanga, South Africa. African Invertebrates 60(2): 239-253. https://doi.org/10.3897/afrinvertebr.60.39538
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A new species of Coenosia Meigen, 1826 is described, C. flagelliseta sp. nov., belonging to a new aberrant group with apically globular orbital setae, previously only known from male specimens in two species. A female from this unique group is also described for the first time, having tergite 6 of the ovipositor atypical for the Coenosiini. The affinities of the group and the species within are discussed.
Diptera, Muscidae, Coenosia, new species, Afrotropical, South Africa.
Coenosia Meigen, 1826 is considered one of the most speciose genera of muscids in the world, with more than 120 species occurring in the Afrotropical Region (
Material from Mariepskop State Forest was sampled using a licence from the Department of Agriculture, Forestry and Fisheries, South Africa. All specimens were sampled together in one Gressitt & Gressitt-style Malaise trap erected over a ravine (arrowed) on Mariepskop (Figs
Specimens were dissected and macerated in 10% potassium hydroxide (KOH). Photographs were taken with a Leica EZ4 stereomicroscope and built-in 5MP camera and stacked using Adobe Photoshop CC 2019. Line drawings were made using a Zeiss microscope with drawing tube and digitally inked using Adobe Illustrator CC 2019. Drawings and photos of C. globuliseta and C. macrotriseta are reused or modified from
Material examined cites the labels directly, with additional author-interpreted information provided in brackets.
Morphological terminology follows that of
From the Latin flagellum (whip) and seta (bristle) referring to the delicate whip-like setae and setulae covering the scutum of the males.
Males can easily be distinguished from other species by their femora, pleura and scutum having some setae differentiated as delicate whip-like setulae, in combination with apically globular frontal and orbital setae. The female has the ovipositor with an atypical tergite 6, which is a fused, broad plate with a basal emargination, compared to the typical and, up to now, considered synapomorphic, slender paired plates of other Coenosia.
Male. Holotype ♂ measurements (mm): body length: 4.72; head: 0.92; thorax: 1.80; abdomen: 2.00; wing: 4.52; ratios (length/width): frontal plate 3.25.
Head
(Fig.
Coenosia spp. heads, lateral view 7 C. flagelliseta sp. nov. ♂ 8 C. flagelliseta sp. nov. ♀ 9 C. macrotriseta ♂ 10 C. globuliseta ♂. Figs 9, 10 modified (
Thorax
(Fig.
Legs: Grey, dusted appearance, except for pair of mid coxae with glossy posterior. Joints between femur, tibia and tarsal segments, as well as trochanters amber in colour.
Leg chaetation (standard appearance, i.e. not whip-like, unless stated otherwise): Fore femur with posterior surface covered in whip-like setulae, one posterodorsal seta, one posterodorsal row of whip-like setae. Fore tibia with one median posterior seta, one dorsal preapical seta. Fore tarsus with one sub-basal ventral seta on basal segment. Mid femur with one supramedian anterior seta, one anterior row of whip-like setae, one supramedian posteroventral whip-like seta, one posteroventral row of whip-like setae. Mid tibia with one medial posterior seta, one preapical posterior seta, one preapical dorsal seta, one preapical posteroventral seta, one apical ventral seta, one apical dorsal seta. Hind femur with an antero- and posteroventral row of whip-like setae, one anterodorsal row of whip-like seta, one sub-basal anterodorsal seta, one supramedian anterodorsal seta, one sub-basal dorsal seta, one median anterodorsal seta, one sub-basal posteroventral seta, one median posteroventral seta, one preapical dorsal seta, one preapical ventral seta. Hind tibia with one median anterodorsal seta, one preapical dorsal seta, one apical ventral seta, one apical anteroventral seta. Fore, mid and hind basal and 2nd tarsal segments with ventral setulae appearing somewhat erect.
Abdomen and terminalia
(Figs
Coenosia spp. ♂, terminalia. C. flagelliseta sp. nov. 17 sternite 5 18 cercal plate, 19 surstylus and cercal plate, lateral view. C. macrotriseta 20 sternite 5 21 cercal plate 22 surstylus and cercal plate, lateral view. C. globuliseta 23 sternite 5 24 cercal plate 25 surstylus and cercal plate, lateral view. Figs 20–25 modified (
Coenosia spp. ♂, phallic complex 26 C. flagelliseta sp. nov. 27 C. macrotriseta 28 C. globuliseta. Coenosia flagelliseta sp. nov. ♀, ovipositor 29 dorsal view 30 ventral view. Figs 27, 28 modified (
Female. Allotype ♀ measurements (mm): body length: 5.96; head: 0.96; thorax: 2.12; abdomen: 2.88; wing: 4.91; ratios (length/width): frontal plate 1.86.
Head
(Fig.
Thorax
(Fig.
Legs: Grey, dusted appearance, except for pair of mid coxae with glossy posterior. Joints between femur, tibia and tarsal segments, as well as trochanters, amber in colour.
Leg chaetation (all non-whip-like): Fore femur with one row each of posteroventral and posterodorsal setae. Fore tibia with one median posterior seta, two preapical posteroventral setae, one apical dorsal seta, one apical posterodorsal seta. Fore tarsus with one sub-basal ventral seta on basal segment. Mid femur with one supramedian anterior seta, one median anterior seta, one preapical posterodorsal seta, one preapical posterior seta, one supramedian ventral seta, one row of anteroventral setae; lacking anterior preapical seta. Mid tibia with one preapical dorsal seta, one apical ventral seta, one apical posteroventral seta, one apical anterior seta, one median seta, one supramedian posterior seta, one median anterodorsal seta. Hind femur with a row of anterodorsal setae, one supramedian ventral seta, one supramedian posteroventral seta, one medial posteroventral seta, one basal dorsal seta, one basal posteroventral seta, one sub-basal posteroventral seta, one sub-basal anteroventral seta, one supramedian anteroventral seta, three subapical anteroventral setae. Hind tibia with one medial anterodorsal seta, one preapical anterodorsal seta, one apical anteroventral seta. Fore, mid and hind basal and 2nd tarsal segments with ventral setulae appearing somewhat erect.
Abdomen:
All tergites with dark, shiny, longitudinal markings, taking up most of dorsal surface, markings split in middle by median vitta. Tergites 3 and 4 with some laterally situated setae having dark markings around bases, as an extension of the aforementioned longitudinal markings. Sternite 1 bare. Ovipositor as in (Figs
RSA [SOUTH AFRICA]: Mpumalanga, Mariepskop State Forest, Radar station road at: 24.5466S, 30.8646E; 26–28.i.2017; 1,885 m a.s.l.; Kirk-Spriggs, A.H. & Muller, B.S.; Malaise trap over ravine, Northern Escarpment Afromontane Fynbos.
Holotype ♂, micro-pinned. Original label [// indicates label; / indicates line break]: “RSA: Mpumalanga / Mariepskop State Forest / Radar station road at: / 24.5466°S, 30.8646°E / 26–28.i.2017, 1,885 m [a.s.l.] / Kirk-Spriggs & Muller // Malaise trap / over ravine / Northern Escarpment /Afromontane Fynbos // Holotype ♂ / Coenosia flagelliseta sp. nov. / B.S. Muller 2019 [red label] // BMSA(D) / 02271 // BMSA type / no. 306 [red label]. [Specimen deposited in the National Museum, Bloemfontein, South Africa].
Paratype ♀, micro-pinned, genitalia dissected, stored together with abdomen in vial under specimen. Same data as for Holotype. Paratype ♀ / Coenosia flagelliseta sp. nov. / B.S. Muller 2019 [red label]// BMSA(D) / 02273 // BMSA type / no. 307 [red label]. [Specimen deposited in the National Museum, Bloemfontein, South Africa].
Paratype ♂, micro-pinned, genitalia dissected, stored together with abdomen in vial under specimen. Same data as for Holotype. Paratype ♂ / Coenosia flagelliseta sp. nov. / B.S. Muller 2019 [red label]// NMSA-DIP / 132993 // NMSA type / no. 2937 [red label]. [Specimen deposited in the KwaZulu-Natal Museum, Pietermaritzburg, South Africa].
South Africa. Only known from type locality.
Males with two pairs of frontal and one pair apically globular orbital setae. Frontal plate and frontal-orbital plates silver-white dusted. Dorsocentral setae (with the exception of the postsutural posterior pair) appearing setulae-like, making them almost indistinguishable from the preceding and surrounding setulae. Trochanters dark amber in colour. Preapical dorsal and anterodorsal setae on hind tibia absent.
Holotype: SOUTH AFRICA • ♂;Western Cape, Oudtshoorn district, Moeras-River Farm (209); 33°48'S, 22°03'E; 525 m [a.s.l.]; Early September 2007 [ix.2007]; G.P.B. Davies; Dry Karoo scrub with flowers; [red label, red ink] Holotype ♂ 1806; Coenosia macrotriseta sp. nov., det. B. Muller 2013; NMSA-Dip. 70333. NMSA type no. 1806.
Genitalia dissected, with abdomen in vial under specimen.
South Africa. Only known from type locality.
Coenosia globuliseta:
Coenosia longiseta Zielke, 1971: 301 [junior homonym of C. longiseta Stein, 1906].
Males with one pair apically globular orbital setae, frontal setae not specialised. Frontal plate and fronto-orbital plates golden-silver dusted. Trochanters and knees orange. Preapical dorsal and anterodorsal setae on hind tibia absent.
Holotype: SOUTH AFRICA • ♂; KwaZulu-Natal, Cathedral Peak area [28.9502S 29.2053E, max. uncertainty 2.5 km], Natal Drakensberg; Alt. 7700 ft [a.s.l.]; 20 Mar. 1955 [20.iii.1955]; B. Stuckenberg; [red label] Holotype, Coenosia longiseta sp. nov., det. E. Zielke 1969; NMSA-Dip. 37487; NMSA type no. 1750.
Genitalia dissected, with abdomen in vial under specimen.
South Africa. Only known from type locality.
All three species key to the C. semifumosa group using the key provided by Emden (1940). However, none can be keyed out past couplet 5 “Hind tibia with two preapical setae (an ad [anterodorsal] and a d [dorsal] one)”. Coenosia flagelliseta sp. nov. has a preapical dorsal seta on its hind tibia, but no preapical anterodorsal seta, whilst C. globuliseta and C. macrotriseta have neither a preapical dorsal or anterodorsal seta. The three species could be considered to form a separate group, based on the presence of one pair of apically globular orbital setae, thus far unique to Coenosia or any other muscid known to the author, herein designated as the “globuliseta-group”. The pair of orbital setae in the males appears somewhat proclinate and not reclinate as in other Coenosiini. The female of C. flagelliseta sp. nov. however does have a pair of reclinate orbital setae. All three species also have broad gena and unusually projecting facial margins, which could also help identify the group when occurring in combination with the apically globular orbital setae in the males.
The female of C. flagelliseta sp. nov. has tergite 6 as a broad plate with a basal emargination. This is in contrast to the general ground plan of the Coenosia as treated in
All three species are interestingly disjunct in their distribution (Fig.
Coenosia flagelliseta sp. nov. was collected on top of Mariepskop, Mpumalanga, South Africa in a ravine (Figs
Coenosia globuliseta was collected in 1955, with little locality information available apart from its being collected in the “Cathedral Peak area”. Considering current vegetation maps (
Coenosia macrotriseta was sampled much more recently (2007) with its exact coordinates recorded, occurring in Northern Outeniqua Sandstone Fynbos, which occurs below 1,300 m a.s.l.
Coenosia are regarded as obligate predators, but interestingly both the male and female of C. flagelliseta sp. nov. had nectar in their midgut contents, pointing to atypical feeding behaviour. Published accounts of Coenosiini as nectar feeders and pollinators are somewhat sparse, especially for South Africa.
BSM thanks the reviewers for their constructive inputs, John Midgley and Kirstin Williams for their hospitality at KwaZulu-Natal Museum, the National Museum for its support and Richard Green of the Department of Agriculture, Forestry and Fisheries for assistance with the research permit application.