Curranosia vanemdeni, Zielke, 2020

Zielke, Eberhard, 2020, Two new species of the genus Curranosia PATERSON, 1957 (Diptera: Muscidae) from the Afrotropical Region, Beiträge Zur Entomologie = Contributions to Entomology 70 (1), pp. 197-202 : 199-200

Curranosia vanemdeni spec. nov.

urn:lsid:zoobank.org:act:192F65AF-3E14-4DDE-921C-DB840B8A06B4

Material examined:  holotype ( Fig. 1 ) is marked with following labels: “ Kenya Colony, 1933, zebra dung, C. B. Symes; Pres. by Com. Inst. Ent. B. M. 1950-323” and “ Pyrellia sp. n.? van Emden, det. 1940” .

The specimen is somewhat dirty, the right mid leg is lacking, and the membrane of the left wing is slightly torn. The damage did not hamper the identification of the specimen.

Description (male): Head ground-colour ochrebrownish, silver-white dusted. Eyes large, practically bare, anterior facets near to frons distinctly enlarged, facets of outer side of eye smaller; shortest distance between eyes slightly shorter than diameter of anterior ocellus. Frontoorbital plates touching over almost all of their length, width of fronto-orbital plate at shortest distance between eyes about as wide as diameter of the adjacent facets. Parafacials in upper half almost parallel-sided, dilating in lower half, at level of insertion of arista to postpedicel about as broad as diameter of anterior ocellus. In profile mouthparts protruding, upper mouth margin beyond profrons ( Fig. 1 ). Width of gena at lowest eye margin about half the length of postpedicel. Face, fronto-orbital plates, parafacials and genae brownish and, except upper two thirds of fronto-orbital plates, silver-white dusted. Antennal segments dark brown, postpedicel brownishgrey dusted. Postpedicel short, about 2.5 times as long as broad and twice as long as pedicel. Arista brown, at basis somewhat thickened, barely 1.5 times as long as length of postpedicel, longest dorsal hairs of arista more than twice as long as width of postpedicel. Fronto-orbital plate throughout its length with a row of densely standing setulose hairs, the hairs in front of ocellar tubercle either inclinate or proclinate, hairs at level of ocellar tubercle shorter and more reclinate. Parafacial bare. Vibrissal setae strong and distinctly longer than longest surrounding peristomal setae. Ventral part of gena covered with short setulose hairs, postgena and post-occipital surface with longer dark setulose hairs. Proboscis ( Fig. 1 ) long and conspicuously slender, at least six times as long as its diameter, dark, prementum with some greenish-blue reflections; labella rather short, almost knob-like; palpus brown, basal half very slender, apically distinctly clavate, about as long as prementum.

Thorax with mesonotum and anterior pleura depending on quality of light shining greenish-blue or predominantly blue, at some points of view with weak violet reflections. When viewed from behind presutural part of mesonotum with a broad whitish dusted stripe reaching the transverse suture. Scutellum of about same colour as mesonotum but somewhat more dark bluish. Posterior pleura predominantly shining brownish, depending on angle of viewing with some violet-bluish reflections, all pleura at some points of view more or less greyish dusted. Anterior spiracle contrasting white ( Fig. 1 ), p osterior spiracle brown. Dorsocentrals 2+4; acrostichals 0 + 1, three postpronotal setae, the inner one only slightly shorter than the outer ones; two notopleural setae, posterior one slightly longer, notopleuron densely haired; pre-alar seta about two thirds as long as posterior notopleural seta; one intra-alar seta. Infra-alar bulla without distinct setulae, suprasquamal ridge with fine, but distinct seta-like hairs, golden-yellow coloured. Prosternum bare, anepimeron with longer hairs on the posterior surface. Proepimeral area and katepimeron bare; meron with several hairs below posterior spiracle. Katepisternals 1+3, the lower two very close to the posterior seta and shorter. Anepisternum with a short but distinct seta anteriorly almost opposite to anterior notopleural seta, posterior margin with a row of 6 or 7 well-developed setae and some much shorter interstitial hairs. Scutellum with a pair each of strong apical, strong lateral and strong subapical setae, basal setae much smaller and barely distinguishable from long ground hair; lateral surface and margin to the ventral surface of scutellum distinctly haired.

Wing membrane hyaline and uniformly covered with microtrichia, cross-veins and surrounding membrane not infuscate. Tegula dark brownish, basicosta contrasting yellowish, veins yellowish to brownish. Costal spine not much longer than surrounding bristles. Distal end of stem vein dorsally and ventrally with a hair-like seta; radial node and vein R 4+5 dorsally with a row of strong setulae reaching cross-vein r-m, ventrally with weaker setulae reaching midway to r-m. Vein M 1 apically distinctly curved to vein R 4+5, the distance between the two veins at wing margin distinctly less than the length of cross-vein r-m, the latter clearly basad of the point where vein R 1 enters costa; distal cross-vein dm-cu sinuous and oblique. Calypters whitish transparent, lower calypter at some angles of view with a weak yellowish-brownish shimmer, margins predominantly whitish, lower calypter about twice as long as upper calypter. Basis of haltere brownish, stem yellow, knob predominantly whitish ( Fig. 1 ).

Legs all brown, femora at some points of viewing with greenish-blue reflections, tibiae at some points of view with a yellowish-ochre shine. Pulvilli and claws clearly shorter than the corresponding tarsomere. Fore femur with complete rows of posterodorsal and posteroventral setae. Fore tibia without median posterior seta. Mid femur with complete rows of anteroventral and posteroventral setulose hairs, length of hairs conspicuously long at basis, decreasing over the length of femur and rather short at apical third, at middle third of femur a row of distinct but not very long anterior setae, preapically three strong posterodorsal setae. Mid tibia with four posterior setae at least as long as diameter of tibia, a conspicuous posteroventral seta at least twice as long as diameter of tibia distally at the middle third of tibia and one distinct anterior seta at apical third ( Fig. 1 ), longer than diameter of tibia. Hind coxa bare on posterior surface. Hind femur with a dense row of strong anterodorsal setae and complete rows of long anteroventral and posteroventral seta-like hairs, partly slightly curved, and at basal half with several long ventral hairs between the two rows, preapically two strong posterior to posterodorsal setae. Hind tibia with a row of about six anterodorsal setae somewhat varying in length but not as long as diameter of tibia, two distinct anteroventral setae at middle third, at apical third a strong and long posterodorsal seta.

Abdomen without specific pattern, depending on quality of light shining dark bluish-green or bluish with strong reflections and depending on point of viewing with small flexible glossy ochre-brownish to brownish-violet areas changing to bluish reflections when angle of light is changed.Anterior half of syntergite 1+2 dorsally and laterally more shining brownish. Tergite 3 with some stronger marginal setae, tergites 4 and 5 with complete rows of distinct marginals and laterally with few longer discals. Ventral parts of tergites predominantly concolorous with dorsal parts. Sternite 1 densely haired, sternites mainly brownish.

Male genitalia. The species is distinguished from the known species of the genus by several taxonomic characteristics. Therefore it has been deemed wiser to refrain from extracting the genitalia to avoid inflicting damage on the hitherto only available specimen.

Measurements. Length of body about 6 mm; length of wing about 6 mm.

Etymology: The holotype had already been examined by van Emden in 1940 who did not identify the Muscidae down to species level but labelled the specimen as questionable Pyrellia spec. nov. Since this specimen is characterized by a combination of features, that did not match the valid criteria of the known Muscidae genera at that period, it proved to be difficult to identify the genus to which the specimen best fits. To acknowledge this attempt to find the most suitable genus for the specimen, the species is name is dedicated to van Emden. The name vanemdeni is a noun in the genitive case.

Diagnosis: The specimen of Curranosia vanemdeni spec. nov. runs in the key to Curranosia species ( ZIELKE 1971a) to Curranosia spekei s. str. (JAENNICKE, 1867). Both species are distinguished by several taxonomic features, for example protruding mouthparts, a slender proboscis and anterior seta at the apical third of the middle tibia, complete row of long posteroventral setulose hairs and only two anteroventral setae on the posterior femur and in addition the mesonotum is marked only by a broad whitish dusted median longitudinal stripe in C. vanemdeni . In contrast to these, C. spekei s. str. has no strongly projecting mouthparts and the proboscis is not strikingly slender, there is no anterior seta on mid tibia and no complete row of long posteroventrals on hind femur, but hind tibia has 3–4 anteroventral setae and the surface of anterior part of mesonotum is intensely greyish-white dusted.

Figures

Fig. 1: Curranosia vanemdeni spec. nov., male holotype, lateral view (bar = 1mm). a = anterior seta of mid tibia.