Curranosia setissima, Zielke, 2021

Zielke, Eberhard, 2021, Descriptions of two new African Curranosia species with characteristics not yet reported from the genus and remarks on the subspecies of Curranosia spekei s. l. (Diptera; Muscidae), Beiträge Zur Entomologie = Contributions to Entomology 71 (1), pp. 167-176 : 168-170

Curranosia setissima spec. nov.

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Material examined:  holotype, Uganda, Ruwenzori Range , Kilembe 4.000 ft.; Dec. 1934 - Jan. 1935,

F. W. Edwards, B. M. E. Afr. Exp. B. M. 1935-203; the specimen is lacking the right fore and hind leg, the right wing membrane is ruptured and the abdominal segments have shrunk and are strongly bent downwards towards the thorax. The holotype bears two identification labels which read “( Pyrellia )  bonnarius van Emden det. 1942” and “ Orthellia sp. nr. distincta, van Emden det. 1942”. The male paratype with the same data as holotype is lacking the right mid leg and both hind legs. The abdomen is extremely shrunk, somewhat twisted and apically the hypopygium is dented. Despite the deficits, the identification and description of the new species were not affected .

Description (male): Head ground-colour brown to dark brown ( Figs 1 +2). Eyes practically bare, without areas of strikingly enlarged facets on the front part of eye. Shortest distance between margins of eyes about twice as wide as diameter of anterior ocellus ( Fig. 2 ). Frontoorbital plates are separated by a frontal vitta about as wide as fronto-orbital plate, width of fronto-orbital plate at shortest distance about half as broad as diameter of anterior ocellus. Parafacial at level of basis of antenna as broad as diameter of anterior ocellus, slightly dilating all over the length to barely half the width of postpedicel. When viewed from anterior face matt brown, parafacial, and fronto-orbital plate brown, gena with a reddish-brown tinge. At certain angle of light face and parafacial more or less greyish-whitish dusted. Pedicel dark brown somewhat shining, postpedicel dark brown and depending on angle of view very weakly greyish dusted. In profile upper mouth part about in line with profrons ( Fig. 1 ). Width of gena at lowest eye margin about half the length of postpedicel. Postpedicel about three times as long as deep and about 2.2 times as long as pedicel. Arista brown, slightly longer than postpedicel, longest dorsal hairs of arista more than twice as long as depth of postpedicel. Ocellar setae not distinguishable from setulae. Fronto-orbital plate throughout its length with a row of about 10 hairs, not much longer than half the length of postpedicel, the anterior hairs somewhat stronger and somewhat longer; hairs of the anterior half inclinate, of posterior half predominantly proclinate. Vibrissals about 1.5 times as long as the longest surrounding peristomal setae. Gena with dark reddish-brown hair-like setae. Proboscis rather short ( Fig. 1 ), brown; prementum shining, length of labella approximately 1.5 times the depth of proboscis; palpus brown, apically more darkened, clavate and somewhat longer than prementum.

Thorax including scutellum uniformly dark blue-violet, shining, with bluish or violet reflections, depending on angle of view. Anterior surface of presutural part of mesonotum with a pale brownish pollinated broad median strip almost reaching the suture, at certain angles of view behind each postpronotal lobe a short pale brownish dusted strip-like patch. Anterior pleura shining dark violet, katepisternum at some points of viewing slightly whitish dusted, posterior pleura such as meron, katepimeron and anepimeron shining brownish. When viewed directly from posterior mesonotum partly with a layer of pale-brownish dust, when viewed from anterior pleura partly light brownish dusted. Anterior spiracle contrasting white, posterior spiracle brownish. Mesonotum well covered with seta-like short hairs. Acrostichals 0+1, dorsocentrals 2+4, the most anterior postsutural seta not much longer than the ground hair, but distinguishable, three postpronotal setae, the inner one somewhat shorter than the two outer setae; posthumeral seta 1; presutural seta 1; notopleuron with several setulae, two notopleural setae, the anterior seta somewhat longer; pre-alar seta almost as long as posterior notopleural seta; the posterior supra-alar seta distinctly shorter; one strong intra-alar seta, three post-alar setae. Infra-alar bulla without setulae, suprasquamal ridge setulose. Prosternum with few hairs, anepimeron haired. Proepimeral area and katepimeron bare; meron with some hairs below posterior spiracle and setulae above hind coxa. Katepisternals 1+3, anepisternal setae 1+7 and few interstitial seta-like hairs, clearly shorter than the setae. Scutellum with a pair each of long apical setae, subapical setae and lateral setae, all long and well developed; the basal setae barely distinguishable from seta-like ground-hair; lateral surface and margin to ventral surface with fine hairs.

Wing membrane hyaline, uniformly covered with microtrichia. Basis of wing not conspicuously clouded, tegula and basicosta dark brown to blackish, veins brown. Costal spine barely distinguishable from surrounding bristles. Subcostal sclerite with two distinct setae, stem vein at distal end before junction of radial veins R 1 and R 2-5 dorsally with one curved hair and ventrally with a well-developed setula and a strikingly long hair-like seta ( Fig. 3 ), which exceeds beyond the radial node of vein R 4+5. Radial node and vein R 4+5 dorsally and ventrally with a row of distinct setulae, exceeding cross-vein r-m. Vein M curved forward obtusely to vein R 4+ 5 in distal half of wing without inward dent beyond bend. Cross-vein r-m basad of the point where vein R 1 enters costa; distal cross-vein dm-cu oblique and slightly sinusoid. Upper calypter hyaline transparent with white margin that is marked at certain angles of view with a very narrow black seam; lateral connection of upper and lower calypter white with a white margin, lower calypter brown transparent and at least twice as big as upper calypter. Haltere with stem yellow, knob pale yellow.

Legs dark brown, somewhat shiny. Claws and pulvilli well developed but rather short. Fore femur with complete rows of posterodorsal and posteroventral setae, posterodorsals about as long as depth of femur at their insertion, posteroventrals distinctly longer than depth of femur. Fore tibia without median posterior seta. Approximately the basal three quarters of mid femur with a row each of anteroventral and posteroventral hairs, almost as long as depth of femur at level of their insertion, in distal half few anterior bristles somewhat stronger than the bristles covering the anterior surface but barely half as long as depth of femur, and a row of posterior bristle-like setae, the three most apical setae of the row significantly stronger and located more postero-dorsally. Mid tibia with about four strong posterior or posterodorsal setae of varying length and in distal half a longer posteroventral seta. Hind femur with a complete row of anterodorsal setae, strong and about as long as depth of femur, and a complete row of anteroventrals, at apical half more seta-like and somewhat longer than depth of femur or anterodorsal setae, in basal half more hair-like and about as long as depth of femur, at least basal half of femur with a row of posteroventral hair-like setae some of which much longer than depth of femur and the other setae; pre-apically two strong posterodorsal bristle-like setae. Hind tibia with one anterodorsal and five anteroventral setae, all barely as long as diameter of tibia, the three more apical located anteroventrals distinctly stronger than the basal ones, and with one posterodorsal seta about twice as long as diameter of tibia.

Abdomen uniformly dark violet or, depending on angle of light, dark bluish, shining with little bluish or violet reflections and without white pollinosity. Tergites 3 and 4 laterally with few seta-like hairs, dorsal surfaces without erected hairs, tergite 5 only with erected seta-like hairs and a complete row of long marginal setae. Sternite 1 haired.

Male genitalia: The species is distinctly distinguished from the known species of the genus by several taxonomic characteristics and the differentiation does not depend on the male genitalia. However, since the abdomen of the paratype was crumpled and twisted and practically unusable for taxonomic purposes ( Fig. 4 ) and the hypopygium was indented and glued with dirt ( Fig. 5 ), the abdomen was removed in order to examine the male genitals, if possible. The abdomen was softened in a mixture of water and a little of 70 % ethanol and the still very hard hypopygium was extracted and transferred into 15 % KOH solution. Despite several hours in KOH solution the hypopygium remained hard and brittle. When it was finally dissected, it broke into pieces. The various parts were cleaned and pictures ( Fig. 6 ) of the separated cercal plates were taken. Even if the separated cercal plates no longer reflect the species-specific shape of the hypopygium, the tooth-like spines on the edge of the cercal plates indicate the similarity to the genitals of the pilarara -group ( ZIELKE 1971, NIHEI & CARVALHO 2009).

Measurements: Length of body about 7.5 mm; length of wing about 7 mm.

Female: Not known.

Etymology: The species name setissima is a female adjective and a combination of seta and longissima (Latin = the longest) and refers to the conspicuously long ventral hairlike seta on the distal part of the stem vein of the new species.

Diagnosis: The taxonomic features of Curranosia setissima spec. nov. lead in the key to the species of the genus ( ZIELKE 1971) directly to Curranosia spekei pilarara ( SNYDER, 1951) . However, when C. setissima was directly compared with the male holotype of C. spekei pilarara , further distinguishing features were found. The frons of C. spekei pilarara is about as broad as the anterior ocellus, the frons of C. setissima is twice as broad as the anterior ocellus. The presutural part of the mesonotum of the holotype of C. spekei pilarara is predominantly whitish and in C. setissima pale brownish dusted. Curranosia spekei pilarara is marked by 2+3 dorsocentral setae, the most anterior postsutural seta small, and 1+2 katepisternal setae; the new species has 2+3-4 dorsocentrals, the second postsutural seta of four setae very distinct, the first one small and barely recognizable, and 1+3 katepisternals. There are two short ventral setulae at the end of stem vein of C. spekei pilarara , whereas C. setissima is marked by one very distinct setula ( Fig. 3 ) and one conspicuously long hair-like seta reaching at least the radial node. The holotype has about one or two conspicuously long posteroventrals present in the middle third of hind femur which are much longer than the anteroventral hairs in basal half; the hind femur of C. setissima is marked by several long anteroventral and posteroventral hairs in the basal half, all more or less of about equal length.

Figures

Figs 1–3: Curranosia setissima spec. nov,  holotype; 1. Head, lateral view, 2. Head viewed from anterior, arrow pointing to anterior ocellus; 3. Ventral surface of wing, setula (s) and long hair-like seta (h) on the distal part of stem vein, e = end of seta, barely recognizable in the image, n = radial node. (Figs 1 and 2: bar = 0.5 mm; Fig. 3: bar = 0.2 mm.)

Figs 4–6: Curranosia setissima spec. nov.,  paratype; 4. Abdomen photographed before it was removed, arrow points to crumpled and dented parts of the completely shrunk and twisted abdomen (bar = 0.5 mm); 5. Hypopygium indented in the crumpled apical part (arrow) of abdomen, glued with dirt (bar = 1 mm); 6. Separated cercal plates of hypopygium s = tooth-likespines at themarginof cercalplate(bar = 0.1 mm).