Three new Coenosia Meigen species from Madagascar (Diptera: Muscidae)

: Three new species, Coenosia circuita sp. n. , Coenosia grunowiana sp. n. and Coenosia neaurifa sp. n. are described from Madagascar as new to science. The identification key to the species of the Afrotropical group “ Coenosia ” created in 1940 by Van Emden has been updated and considers now 14 species.


Introduction
According to Systema Dipterorum website (Evenhuis & Pape, 2023) around 472 species are known of Coenosia Meigen, 1826 (Muscidae: Coenosiinae: Coenosiini), the third largest genus in the Muscidae family after Phaonia Robineau-Desvoidy, 1830 and Helina Robineau-Desvoidy, 1830 which have 870 and 780 species, respectively.The genus is represented almost worldwide, albeit in different numbers of species and prevalence.So far, around 120 Coenosia species occur in the Afrotropical Region.This makes Coenosia the second most species-rich genus in the region after the genus Atherigona Rondani, 1856.In Madagascar, however, Coenosia is represented by only a few species, as shown by the publication on Malagasy Muscidae by Couri et al. (2006).According to the authors, only seven species have been found in Madagascar so far, in addition they described another species, new to science, from that area.Investigations carried out at the Institute of Biodiversity and Ecosystem Research (IBER), Sofia, Bulgaria on unidentified muscid material from Madagascar revealed apart from various other Muscidae several specimens of Coenosia.The flies were assigned to species using the identification keys to the species-groups within the genus, created by Van Em-den (1940).Only three specimens were found belonging to the so-called group "Coenosia".However, the combination of their taxonomic characteristics did neither match the five species listed in the key nor the other six species, assigned to the group "Coenosia" in the years following the publication of the identification key.They are therefore considered as representatives of unknown species and are hereinafter described as Coenosia circuita sp.n., Coenosia grunowiana sp.n. and Coenosia neaurifa sp.n.Since the number of species belonging to the group "Coenosia" has more than doubled since the publication by Van Emden his key was supplemented by the three newly described species and the other six taxa that had not yet been considered, which are Coenosia brunneigena Van Emden, 1940, Coenosia cryptica Paterson, 1956, Coenosia exilis Pont, 1969, Coenosia flavivibrissata Stein, 1918, Coenosia melanomeros Van Emden, 1951and Coenosia stuckenbergi Zielke 1971.The possible assignment of Coenosia aberrans Couri, Pont & Penny, 2006 to this group is discussed.

Materials and methods
The origin of the material examined as well as the processing methods and the identification of the flies were repeatedly described in detail (e.g.Zielke, 2021aZielke, , 2016b)).Therefore, some sections of "Materials and methods" have been taken verbatim from recent publications and adapted with regard to the preparation and identification of the fairly small specimens of Coenosia.
The unidentified muscid material was preserved in high-percent ethanol and came mainly from the remains of insect traps kept in vials at the Moravian Museum, Brno, Czech Republic.Many of the flies, particularly of the small ones, found among the remains were destroyed or had lost body parts crucial to identification.But some specimens, apart from lost setae, were only slightly or not at all damaged and suitable for further processing and identification.These flies were isolated, cleaned in 75% ethanol before being transferred to a solution of 30% ethanol for soaking.They were then mounted on a pin or a minute and marked with a locality label.In order to reduce shrinkage of the small fly bodies due to too sudden drying, the samples were dried slowly in a container at constant humidity.Added acetic acid evaporated and prevented fungal infestation.However, this was only partially successful, many of the small specimens showed more or less some shrinkage.
The identification key for the Madagascan Muscidae species published by Couri et al. (2006) was of little help as it only includes eight species, and it quickly became evident that the collection of unidentified Coenosia specimens from Madagascar consisted of a significantly larger number of different species.Therefore, the keys created by Van Emden (1940) were used und supplemented by Coenosia species from the Afrotropical Region described in the following years after the publication of the keys.For additional check-ups on species of the so-called "Coenosia" group sensu Van Emden (1940) the following publications on African Coenosia were consulted: Couri & Pont (2016a, 2016b), Paterson (1956), Pont (1969), Van Emden (1951) and Zielke (1971).In addition, the new species were also checked against the keys of the earlier authors Stein (1913), Malloch (1922) and Curran (1935), but none of the new species matched any of the species listed in these keys.Moreover, several Coenosia species were studied when visiting the Muscidae collection of the Natural History Museum, London in 2023.The newly described species were compared with the holotypes of similar species, and the available type material and identified specimens of different species of the collection were used for testing the functionality of the updated key.
Morphological terminology follows McAlpine (1981), but postpedicel (Stuckenberg, 1999) is used instead of "first flagellomere" as proposed by McAlpine.As already described previously (Zielke, 2020), the width of the postpedicel seen from the lateral side is called "depth" and the greatest depth of the postpedicel is always used for comparisons and ratio calculations.The length of postpedicel is measured from the most anterior margin of pedicel till the apex of postpedicel.Unless otherwise stated, information on the width of the forehead always refers to the shortest distance between the margins of the eyes.The anterior width of frons is measured directly at the upper margin of lunule.Only the postsutural intra-alar setae are called as such.The socalled intra-alar setae of the presutural part of mesonotum are referred to as posthumeral and presutural setae.When the length of setae or hairs of the femur is compared to the depth of femur, the depth always refers to the point of insertion of the seta or hair.Body length is measured in millimetres (mm).
External morphological features of the specimens were studied using a Zeiss Stemi SV6 stereomicroscope and images were created by means of combination of a Zeiss Discovery 8 stereomicroscope and an AxioCam ERc5s camera.Helicon Focus 6 and Adobe Photoshop CS2 were applied for further processing of the images.
The holotypes of the three new species will be returned to the Moravian Museum upon completion of the study.

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Historia naturalis bulgarica 45 (2023) missing, however their scars are clearly visible; otherwise, the holotype is in good condition.Etymology: The epithet is a female adjective referring slightly modified to the circuit where it was collected.
Description (female): Head.Ground-colour dark to blackish, depending on incidence of light partly dusted greyish.Dichoptic; eye practically bare, facets of about equal size.Frons almost parallel-sided (Fig. 3) slightly dilated towards vertex, longer than wide, sparse but fairly long, in two rudimentary irregular rows; 1+3 strong dorsocentral setae; postpronotal setae 2, fairly strong, the outer one clearly longer and stronger than the inner seta; posthumeral seta 1, presutural seta 1, both strong, the presutural seta significantly longer; notopleural setae 2, the posterior somewhat shorter; pre-alar seta absent; intra-alars 2, strong; one strikingly long supra-alar seta and three post-alar seta.Proepisternal and proepimeral setae strong, the lower proepimeral seta distinctly weaker, curved downward, not surrounded by hairs.Katepisternal setae in an equilateral triangle, the latter with a few erect hairs on its surface, the lower seta clearly weaker.Anepisternal setae 1+5, the anterior seta fairly short, the setae of the posterior row strong but of different length, practically without distinct interstitial hairs.Scutellum each with a pair of scars of strong and long apical and lateral setae, about equally strong, no other scars of setae or setulae detectable on the surface of scutellum.
Wings.Membrane hyaline without a distinct tinge; tegula and basicosta brownish, veins brown; costa reaching apex of vein M; costal spine distinct almost as long as cross-vein r-m.Vein R4+5 very slightly divergent from apex and vein M; cross-vein rm slightly basad of the point where vein R1 enters costa; vein A1 distinctly shorter than half the distance from its base to the wing margin.Calypters fairly small; upper calypter greyish hyaline, margin with a narrow brown frame; lower calypter matt greyish at certain viewing angle with a dark frame, triangularshaped and with a rounded apex, almost 1.5 times as long as upper calypter.Haltere pale yellow.
Legs.Primarily brown (Fig. 1), somewhat shiny and without yellow knees; at certain incidence of light coxae densely dusted pale grey.Fore femur with a complete row of strong posterodorsal setae the longest ones almost as long as depth of femur, and a row of posteroventrals distinctly shorter than depth of femur.Fore tibia with a distinct posteroventral seta at middle third, almost one third as long as length of tibia.Mid femur in basal half a strikingly strong anterior seta longer than depth of femur and one strong anteroventral seta almost as long as depth of femur and at least one strong posteroventral seta almost as long as the anteroventral one, two preapical posterior to posterodorsal bristles.Mid tibia about at midlength with a strong posterodorsal seta and slightly more distal a very strong anterodorsal seta almost half as long as tibia.Hind femur with a and almost as wide as one eye; frontal vitta at midlength about four times as wide as fronto-orbital plate; frontal triangle poorly demarcated, in lateral view reaching the level between the two long frontoorbital setae.Basis of parafacial almost as wide as depth of postpedicel, tapering downwards throughout its length to about a quarter of the depth of the postpedicel.Facial ridge in lower half about as wide as parafacial.Fronto-facial stripe slightly widened to lower vertex and more distinct to the lower margin of eyes, where it is marginally but distinctly wider than frons.Frons longer than face.In profile anterior part of head angular-shaped (Fig. 2); frons conspicuously protruding by almost twice the depth of postpedicel; gena below lowest eye margin about as wide as depth of postpedicel; mouth margin approximately at the same level as the lower margin of the eye.Frontal vitta depending on incidence of light dark brown or blackish, more or less dusted brownish or greyishbrown (Fig. 3); fronto-orbital plate, parafacial, face and gena predominantly dusted greyish, peristomal corner brownish, sparsely dusted.Antenna uniformly dark brown, postpedicel at certain incidence of light very sparsely dusted greyish-brown, pedicel at certain viewing angles densely dusted greyish.Antenna not reaching mouth margin, falling short of margin by the depth of postpedicel.Postpedicel about 2.5 times as long as its depth and twice as long as pedicel.Arista at least 2.5 times as long as length of postpedicel, the longest dorsal hairs almost as long as the diameter of the slightly dilated basis of arista.Fronto-orbital plate with three inclinate fronto-orbital setae; the anterior and the upper seta long, the middle seta distinctly shorter, two or three interstitial seta-like hairs about half as long as the middle seta.Inner vertical seta conspicuously strong, longer than the other setae of the head including the vibrissal seta.Outer vertical seta about half as long as the inner seta and shorter than the postvertical seta which is about as long as the two diverging ocellar setae, the latter ones somewhat shorter than the fronto-orbital seta.Proboscis with prementum shiny dark brown, labella brown slightly longer than depth of proboscis; palpus dark.
Thorax.Ground-colour predominantly brownish (Fig. 1) depending on incidence of light dusted brownish or brownish-grey or somewhat shiny.Mesonotum and scutellum uniformly dusted brownish without any stripes.Pleura predominantly dark and densely dusted brownish or at certain incidence of light brownish-grey.Acrostichals very complete row of strong anterodorsal setae, longer than depth of femur, and with two strong anteroventral setae in apical third, in basal half two fairly short anteroventral setae and two posteroventral hairs about half as long as depth of femur, and a preapical posterodorsal seta.Hind tibia with a rather strong and long anterodorsal seta in midlength and a short anteroventral seta clearly beyond it, preapical one dorsal and one anterodorsal seta each, both setae somewhat shorter than the median anterodorsal seta.
Abdomen.Oval-shaped, apex of last tergite pointed (Fig. 1); predominantly dark, densely dusted brownish, without a specific pattern, at certain incidence of light tergites with a distinct greyish tinge.The lateral and ventral parts of tergites concolourous with the dorsal surface.Marginal setae of tergites 3 to 5 fairly short, about one third as long as the length of the corresponding tergite, only the discals of tergite 5 about half as long as tergite.
Female genitalia.Not investigated.Measurements: Body length 3.2 mm, length of wings 2.9 mm.
Male.Not known.
Diagnosis: Coenosia circuita sp.n. runs in Van Emden's key to Coenosia fordi Van Emden, 1940, however it differs from the latter by a striking conspicuously protruding frons, approximately twice the depth of postpedicel; the gena below the lowest part of eye margin is about as wide as depth of postpedicel; the legs are primarily brown, somewhat shiny, the knees are dark; the apical part of postpedicel is rounded and not acuminate at tip.On the other hand, C. fordi has not such a protruding frons; the gena is at least 1.5 times as wide as depth of postpedicel; not mentioned by Van Emden (1940) but clearly visible at holotype and the four paratypes the apex of postpedicel is clearly acuminate; at least the dark femora predominantly dusted greyish, all knees very narrowly yellowish coloured.
Coenosia grunowiana sp.n.  urn:lsid:zoobank.org:act:658B530C-53FF-4036-A2E3-D1D4B9F8A04C � Material examined: ♂ holotype; locality label reads: "Madagascar Montagne D'Ambre N. P. 1040 m, S12°312'37'' E49°10'15'', YPT, 13-18.I.2016, leg.P. Banar".The left eye is shrunk and the base of antennae somewhat covered by anterior margin of frons.Otherwise, the male is in a good condition.Etymology: The epithet "grunowiana" is a feminine adjective and it is my great pleasure to name this new species after Cornelia Grunow of the Editorial board of "Beiträge zur Entomologie", also known as "Contributions to Entomology" from the Senckenberg Deutsches Entomologisches Institut (SDEI).Cornelia Grunow retired end of 2022 and I would like to take this opportunity to thank her for the always friendly help in completing my submitted manuscripts for printing.Be it that the manuscripts and illustrations had to be converted into a printable format, or, just as essential, that competent experts had to be found to review the manuscript, and who often contributed valuable comments improving the article.
Description (male): Head.Ground-colour depending on viewing angle dark brown or black, only small parts dusted greyish.Dichoptic; eye with few microscopically very small hairs, facets of about equal size.Frons about parallel-sided, longer than wide and as wide as width of an eye (Fig. 5); frontal vitta at midlength at least seven times as wide as fronto-orbital plate, frontal triangle barely distinguishable from frontal vitta, the anterior tip about at level between of third inclinate fronto-orbital seta and reclinate orbital seta.Parafacial at basis of antenna about as wide as depth of postpedicel, strongly tapering in upper quarter and about one third as wide as depth of postpedicel in lower half.Frontofacial stripe almost parallel-sided, only slightly widened to lower margin of eyes, where it is marginally wider than frons.Face not longer than frons.In profile, anterior part of frons protruding by about the depth of postpedicel; gena about two thirds as wide as depth of postpedicel; level of mouth margin about at the level of the lower margin of the eye.In frontal view, fronto-orbital plates dark greyish, frontal vitta depending on incidence of light dark brown or black, parafacial and face predominantly dark brown, gena dark brown.Postpedicel dark brown, at certain incidence of light very sparsely dusted greyish, pedicel dark brown, sparsely dusted greyish at apex.Antenna not reaching mouth margin.Postpedicel about three times as long as deep.Arista about twice as long as length of postpedicel, the longest dorsal hairs about as long as the diameter of the slightly dilated basis of arista.Fronto-orbital plate with three inclinate fronto-orbital setae; the anterior middle seta.Inner vertical seta conspicuously strong and about as long as the height of an eye and longer than the other setae of the head including the vibrissal and the upper seta fairly strong and about as long as the ocellar seta, the middle seta distinctly shorter, two interstitial seta-like hairs about half as long as the seta.Outer vertical seta about half as long as the inner seta and shorter than the postvertical seta which is not quite as long as the two diverging ocellar setae.Proboscis with prementum shiny dark brown, labella brown slightly longer than depth of proboscis; palpus short and slender, slightly clavate, basal third or half dark brown and glossy, apical part brownish-grey.
Thorax.Predominantly brownish, at certain incidence of light with a greyish tinge.Presutural mesonotum dusted greyish-brown with three brown stripes (Fig. 4), the median one along the acrostichal hairs, the paramedian stripes along the presutural dorsocentral setae, barely reaching the transverse suture.Pleura primarily dusted brownish, at certain incidence of light with a greyish tinge.Acrostichals sparse but strong and some are fairly long, in two irregular rows; 1+3 strong dorsocentral setae; postpronotal setae 2, fairly strong, the outer one about twice as long as the inner seta; posthumeral seta 1, presutural seta 1, both setae strong, the presutural seta significantly longer; notopleural setae 2, the posterior somewhat shorter; intra-alars 2 strong ones; one strong and strikingly long supra-alar seta and one long post-alar seta detectable.Scutellum with a pair each of strong and long apical and lateral setae, about equally long, a pair of very short preapical and basal setae about one sixth as long as the lateral and apical setae, no other setulae on the surface of scutellum.Proepisternal and proepimeral setae moderately strong, the lower proepimeral seta curved downward, not surrounded by hairs.Katepisternal setae in an equilateral triangle, the latter with a few erect hairs on its surface, lower and anterior setae about equally strong, posterior setae somewhat longer.Anepisternal setae 1+5, the anterior seta fairly short, the setae of the posterior row strong and of different length, a few interstitial seta-like hairs, about half as long as the setae.
Wings.Membrane sub-hyaline, slightly smoky; tegula pale brownish, basicosta somewhat yellowish, veins brown; costa reaching apex of vein M, costal spine not prominent but almost as long as cross-vein r-m, the bristles of costa up to the height of cross-vein dm-cu standing on gap, the distance between the bristles longer than their length; cross-vein r-m slightly basad of the point where R1 enters costa; vein A1 strikingly short, at most a fifth as long as the distance from its base to the wing margin.Calypters fairly small, greyish hyaline, margins at certain incidence of light with a somewhat darker frame; the lower calypter narrow, slightly elongate, and parallelsided, rounded at apex and somewhat projecting.Halteres yellow.
Legs.Uniformly brown, somewhat shiny, without yellow knees (Figs 4 and 6).Fore femur with an almost complete row of strong posterodorsal setae barely as long as depth of femur and a row of posteroventrals longer than depth of femur.Fore tibia with a moderate posteroventral seta in middle third, barely one third as long as length of tibia.Mid femur with three anterior setae in middle third, the middle seta strong and longer than depth of femur, the two other setae barely as long as depth of femur, in basal third three anteroventrals, one of which about as long as depth of femur, the two others about half as long, and some short posteroventrals of which two or three setae almost as long as the anteroventrals, two preapical posterior to posterodorsal bristles.Mid tibia with a distinct posterodorsal seta at midway and a strong and longer anterodorsal slightly beyond.Hind coxa without setae on posterior inner surface.Hind femur with a complete row of strong, slightly curved anterodorsal setae, about as long as depth of femur, and with two strong anteroventral setae in apical third, the most apical seta longer than depth of femur, in basal half about four short anteroventrals, barely half as long as depth of femur, one distinct posteroventral seta at midlength of femur almost as long as depth of femur, and a preapical posterodorsal seta.Hind tibia with a rather strong anterodorsal seta at midlength and a fairly fine anteroventral seta clearly beyond it, a preapical dorsal seta clearly longer than the median anterodorsal seta, and with a preapical anterodorsal seta about half as long as the dorsal seta.
Abdomen.Somewhat depressed, oblong-ovalshaped; predominantly dusted greyish, depending on viewing angle with a brown median longitudinal stripe extending from posterior part of syntergite 1+2 to apical margin of tergite 4 (Fig. 6).At certain incidence of light apical part of tergite 4 and in apical half of tergite 5 more brownish.The lateral and ventral parts of tergites greyish.Marginal setae of syntergite 1+2 not very distinct, tergite 3 laterally with two long and strong marginals, and tergite 4 with a complete row of long and strong marginals setae, the longest setae of tergite 3 and 4 about as long as the length of the associated tergite, tergite 5 with a row of discal setae, almost as long as the marginals of tergite 4, and a row of distinct marginals about half as long as the discals.Sternites concolourous with tergites.Sternite 1 bare.Male genitalia.Since the male of Coenosia grunowiana sp.n. is clearly distinguished from the other known taxa of the genus on the basis of several other taxonomic characters, the hypopygium is not needed for identification purposes.Therefore, it deemed wiser not to extract the genitalia, to avoid inflicting damage on the hitherto only available specimen of the species.
Measurements: Body length 2.4 mm, length of wings 2.3 mm.
Female.Not known.
Diagnosis: Many Coenosia species are relatively small with a body length between three and five mm, but Coenosia grunowiana sp.n. is strikingly small with barely 2.5 mm.Using Van Emden's key to the Coenosia group the new species ends at couplet 7(8) with C. fordi which has also a certain similarity with the newly described Coenosia circuita sp.n.Both species differ from Coenosia grunowiana sp.n. by a brown thorax depending on incidence of light dusted greyish or brownish-grey, mesonotum without longitudinal stripes; gena at least about as wide as depth of postpedicel; the lower calypter triangularshaped and abdomen uniformly dark, dusted brown or greyish-brown, without a distinct pattern; whereas Coenosia grunowiana sp.n. is marked by a thorax predominantly brownish with a greyish tinge, the mesonotum is dusted greyish brown with three brown longitudinal stripes in the presutural part barely reaching transverse suture; the gena is only about 2/3 as wide as depth of postpedicel and the lower calypter is narrow, somewhat elongate and projecting; the abdomen is predominantly dusted greyish, at certain viewing point with a brown median longitudinal stripe from syntergite 1+2 to apical margin of tergite 4, and the head profile is mainly round and not angular-shaped with a conspicuously protruding frons as in Coenosia circuita sp.n.
Etymology: The epithet is a female adjective, composed and abbreviated from the comment of a preliminary classification "ne (= not) Coenosia aurifacies van Emden, 1940" originating from the first screening of the muscid collection.
Description (female): Head.Ground-colour dark, largely densely dusted whitish-grey (Fig. 9).Dichoptic; eye practically bare, facets of about equal size.Frons (Fig. 8) slightly dilating towards anterior margin, strongly tapering from upper margin of lunule to level of pedicel, frons longer than wide, at vertex about 0.3 times as wide as maximal width of head, at upper margin of lunule about 0.38 times and clearly wider than the width of an eye; frontal vitta at midlength at least four times as wide as fronto-orbital plate at that level; frontal triangle very short, anterior tip slightly below the level of reclinate fronto-orbital seta.Basis of parafacial about two thirds as wide as depth of postpedicel, narrowing to about one third at the level shortly below the arista basis and from there parallel-sided throughout to lower end.Facial ridge in lower half about as wide as parafacial.Fronto-facial stripe at narrowest at level of pedicel, dilating upwards about to the second pair of fronto-orbital setae and then slightly narrowing towards vertex; downwards consistently dilating towards the mouth margin, where it is marginally but distinctly wider than frons.Frons somewhat longer than face.In profile (Fig. 9) anterior part of head rounded; frons not conspicuously protruding but lower mouth margin clearly behind profrons; antenna inserted about at middle of head; parafacial well visible throughout its length, gena below lowest margin of eye about as wide as depth of postpedicel; level of mouth margin about at the level of the lowest eye margin.In anterior view fronto-orbital plate dark greyish, under certain incidence of light with some patches dusted white; frontal vitta dark brown or blackish, the anterior margin above lunule somewhat dark rusty brown, in dorsal view blackish; parafacial, face, facial ridge, peristomal area and gena predominantly densely dusted whitish-grey, parafacial at level of pedicel and basis of postpedicel with a shifting weak patch-like dark shadow, varying in form and size depending on changes of viewing angle.Antenna uniformly dark brown, postpedicel at certain incidence of light sparsely dusted greyish, pedicel at certain viewing angle densely dusted greyish.Antenna not reaching mouth margin, falling short of margin by the depth of postpedicel.Postpedicel slightly more than three times as long as its depth and also three times as long as pedicel, not acuminate at apex (Fig. 9).Arista three times as long as length of postpedicel, the longest dorsal hairs slightly longer than the diameter of the basis of arista.Fronto-orbital plate with four inclinate fronto-orbital setae; the anterior and the upper seta distinctly longer and stronger than the setae in between, and about two or three interstitial seta-like hairs.Inner vertical seta conspicuously strong, outer vertical seta distinctly weaker than the postvertical seta which is almost as strong as the two ocellar setae and clearly stronger and similar to the strong inclinate fronto-orbital setae.Proboscis with prementum shiny dark brown, labella brown slightly longer than depth of proboscis; palpus brown, somewhat clavate and about as long as prementum.
Thorax.Ground-colour predominantly greyish (Fig. 7).The anterior presutural part of mesonotum mainly greyish, the presutural area in front of the transverse suture, the postsutural part and scutellum almost uniformly brown, depending on incidence of light matt, dusted greyish-brown or brownish or somewhat shiny; no distinct pattern recognisable.The surfaces adjacent to mesonotum such as postpronotum, notopleuron, post-alar ridge and the lateral pleura greyish, the latter at certain incidence of light at parts with a weak brownish tinge.Anterior spiracle pale brownish.Acrostichals sparse but fairly long, in two rudimentary irregular rows; 1+3 strong dorsocentral setae; postpronotal setae 2, the outer one clearly stronger than the inner seta; posthumeral seta 1, rather small; presutural seta 1, strong and long; notopleural setae 2, the posterior somewhat shorter; intra-alars 2; supra-alar seta 1 and post-alar setae 2. Scutellum with a pair of scars each of strong and long apical and lateral setae, the scars of lateral setae conspicuously stronger, scars of the basal setae clearly recognisable, albeit distinctly smaller than the scars of the other setae; no scars of pre-apical setae or any other setae or setulae visible.Proepisternal and proepimeral setae strong, the lower proepimeral seta distinctly weaker, curved downward, without neighbouring hairs.Katepisternal setae in an unequal triangle, the lower seta distinctly closer to the posterior than to the anterior seta.The lower seta not much shorter than the two other setae, surface of the triangle with one erect seta-like hair.Anepisternal setae 1+5-6, the anterior seta distinct, the setae of the posterior row strong but of different length, practically no interstitial hairs.
Wings.Membrane hyaline with a smoky tinge; tegula and basicosta yellow, veins brown; costa reaching apex of vein M, costal spine somewhat longer than adjacent bristles of coxa; R4+5 very slightly convergent to apex and vein M; cross-vein rm clearly basad of the point where R1 enters costa; vein A1 very short, barely one third as long as the distance from its base to the wing margin.Calypters fairly small, both greyish hyaline; margin of upper calypter with a narrow brown frame; lower calypter with a broad whitish margin, somewhat elongate and projecting, apically rounded, about 1.5 times as long as upper calypter.Haltere pale yellow.
Legs.Coxae yellowish, densely dusted greyishwhite, trochanters predominantly yellowish, partly pale brown, fore femur predominantly brownish, mid and hind femora with the basal third yellowish, increasingly brownish towards distal half or third and the apical part predominantly brownish, ventral surface with a yellowish tinge; tibiae in general yellow (Fig. 7), at certain incidence of light brownish, tarsi darker than tibiae, depending on viewing angle either dark yellow or brownish, pulvilli and claws well developed but clearly shorter than the last tarsomere.Fore femur with a complete row of strong posterodorsal setae, the longest ones almost as long as depth of femur, and with a row of posteroventral bristles, in which long setae each alternate with short setae, the long setae being longer than the depth of the femur, and the short ones are about half as long.Fore tibia with a moderately long posteroventral seta at middle third.Mid femur in basal two thirds with three or four strong anterior setae the longer ones about as long as depth of femur, and about four posteroventral setae also about as long as depth of femur, at midlength of femur one strong anteroventral seta almost as long and basad three or four setae clearly shorter than depth of femur, two preapical posterior to posterodorsal bristles.Mid tibia with a strong slightly submedian posterodorsal seta and at midlength a very strong and long anterodorsal seta.Hind coxa bare on posterior inner surface.Hind femur with a complete row of strong anterodorsal setae, almost as long as depth of femur, strong anteroventrals in apical third and one strong submedian anteroventral seta; a row of five posteroventral seta-like hairs about as long as depth of femur in basal two thirds, and a preapical posterodorsal bristle.Hind tibia with a rather strong and long anterodorsal seta at midlength and a strong but distinctly shorter anteroventral seta clearly beyond it, preapical a long dorsal and a somewhat shorter anterodorsal seta.

Historia naturalis bulgarica 45 (2023)
Abdomen.Oval, slightly depressed, and pointed at apex, predominantly brown and without a specific pattern, depending on incidence of light in parts paler or darker brown, the four anterior tergites at certain viewing angle partially somewhat sparsely dusted greyish, the last tergite is persistently dusted greyish, regardless of viewing angle.The lateral and ventral parts of tergites concolourous with the dorsal surface.Marginal setae of syntergite 1+2 and 3 fairly short, of tergite 4 somewhat longer, of tergite 5 more hair-like and not as long as the also hair-like discal setae.Sternites brownish, sternite 1 bare.
Female genitalia.Not investigated.Measurements: Body length 3.3 mm, length of wings 3.2 mm.
Male.Not known.
Diagnosis: The new species Coenosia neaurifa runs in Van Emden's key (1940) to C. aurifacies which also has some similarity with Coenosia exilis Pont, 1969.However, the latter species is marked by a rather angular head profile, the postpedicel is reaching the level of the lowest eye-margin, the fore tibia has no submedian posterior seta, the mid tibia is without a submedian anterodorsal seta and the mid femur has only one preapical posterior bristle.The head profile of Coenosia neaurifa sp.n. and C. aurifacies is more round, the postpedicel is fairly short, not reaching the lower mouth margin, fore and mid tibia have the setae present which are lacking in C. exilis and mid femur is armed with two preapical posterior bristles.However, C. aurifacies is characterised by frons and face dusted golden-grey and greyish-white respectively in females, postpedicel is only 2.5 times as long as deep but clearly acuminate at tip, the mesonotum shows three faint narrow vittae, the median one might reach base of scutellum, the coxae are dark but densely dusted grey and the hind femur shows in basal half only one strong posteroventral seta, the abdomen is densely dusted grey, tergites 3 to 5 are marked by a median dark brown narrow vitta, and tergites 3 and 4 each by a pair of round dark brown spots.In contrast to these in Coenosia neaurifa sp.n. frons and face are dusted predominantly greyish, but not yellowish, golden-greyish or whitish, the postpedicel is at least three times as long as deep and not acuminate but rounded at tip, the mesonotum shows no longitudinal stripes, the presutural part is predominantly dusted greyish, the postsutural part more brownish, the coxae are yellow, dusted greyish and the hind femur shows in basal two thirds about five posteroventral seta-like hairs about as long as depth of femur, the abdomen is predominantly brown without a specific pattern, depending on incidence of light in parts paler or darker brown and sparsely dusted greyish, tergite 5 is dusted greyish independent of viewing angle.Van Emden's (1940) identification key to the species of the so-called "Coenosia-group"

Update of
The species belonging to this group are distinguished from the species of the other Afrotropical groups of the genus by the absence of an anterior seta, usually very close to the anterodorsal seta in the middle part of the posterior tibia.However, the females usually and the males occasionally have an anteroventral seta inserted clearly distad from the anterodorsal seta.This anteroventral seta is absent in the specimens of the other groups of the genus.However, these few species which may have been overlooked can be added in the future updated version, just as errors, omissions or inconsistencies in the key will be identified and hopefully corrected in the course of use.

Introduction
The steppe area of Bulgaria, originally occurring in the northern part of the country mainly along the Danube River, is largely destroyed by anthropogenic activity.Small patches are preserved mosaically mainly along steep slopes.Various types of steppe habitats in this area have been classified as relict and endangered (Biserkov et al., 2015), and some of them were regularly visited during entomological expeditions in 2020-2022.As a result a steppe moth species was found (Zlatkov & Sivilov, 2020).In the present paper we provide further records of two rare steppe species that have not been known from Bulgaria.The distributional ranges and the characteristics of the localities indicate that these species are limited to the steppes only.We also discuss the peculiar morphology of their genitalia and provide detailed illustrations.

Methods
Two methods were used for moth collection: light trapping with mercury vapour light bulb and "blacklight" tube (for C. rakosyella) and netting at daytime (for T. irinae).The moths were set in the field and later dissected in the laboratory under a stereomicroscope generally following Robinson (1976).A compound microscope was used for drawing and photography of the genitalia.The moths were photographed under a stereomicroscope (for a complete description of the equipment and techniques see Zlatkov & Sivilov, 2020).The map was created using Quantum GIS 3.28.1-Firenze,ESRI satellite imagery and spatial data provided by geoBoundaries (Runfola et al., 2020).The specimens were preserved in the collection of the Institute of Biodiversity and Ecosystem Research (IBER), Sofia, Bulgaria.

Results and discussion
Ceratoxanthis rakosyella Wieser & Huemer, 2000 Material: 2 ♂♂, Dobrich region, Kapitan Dimitrovo, N 43.9531°, E 27.7053°, 150 m a.s.l., 19.vi.2022, leg. B. Zlatkov & O. Sivilov (IBER).Morphological notes: Forewing length 8.7-8.8 mm (n = 2).The wing pattern is similar to other Ceratoxanthis spp., with a yellow background, rusty brown markings and a mosaic of pale refractive dots in the distal area (Fig. 1 A, B).The male genitalia are highly specialised similarly to other species of the genus (Fig. 1 C).The socii are elliptical pads (in Fig. 1 their flat surface is laterally oriented); the transtilla is trilobed, with a small median part adorned with small acanthae apically and very large lateral parts bearing stout setae medially (Fig. 1 D); the juxta bears flat triangular lateral processes pointed dorsally; the valva is modified with two long, rod-like lateral processes exceeding the length of the valva, with a longitudinal stripe and apex covered with acanthae (Fig. 1 E); the processes are basally connected with the processes of juxta and the juxta proper; the phallus is wide at the base, coalescent with the juxta, apically narrow and tubular, the vesica bears a small stout nondeciduous cornutus (seta) (Fig. 1 F); the valvae are nearly rectangular, with sclerotised costa and strongly sclerotised protruded sacculus, the lateral margin is incised subapically.
Habitat and biology: The habitat is a Danubian loess steppe on a steep slope facing South (Fig. 5).It is endangered and listed in the Red Data Book of Bulgaria (Tzonev, 2015a).Apart from the flight period (second half of May-June), the biology of the species is basically unknown.
Faunistical notes: The species was described from Romania, Dobrogea, Hagieni, after three males (Wieser & Huemer, 2000).Additional 5 male specimens were collected from the same locality (Kovács & Kovács, 2006).Later Bidzilya et al. (2014) and Kavurka et al. (2021) recorded specimens from Ukraine, Lugansk region.The locality from Bulgaria is a new record for the country and the third for the species (Fig. 7).The females are unknown.
Morphological notes: Forewing length in males 5. 5-6.2 mm (x̄ = 5.9, n = 6), in females 5. 5-6.5 mm (x̄ = 5.9, n = 12).The head, including palps, is covered with long fluffy scales, giving a characteristic appearance of the moth (Fig. 3 B).The forewings are with ill-defined creamy costal strigulae continuous with irregular transverse lines, alternating with pale grey-brown lines.The speculum is creamy, with a few black dots terminally.The hindwings in males are whitish, in females they are pale grey (Fig. 2).The male genitalia are with well-developed laterally flattened uncus, the sacculus is protruding in a triangular process distally, the cucullus is bordered proximally with long stout setae (Fig. 3 A).The phallus is subcylindrical, slightly bent ventrally.The vesica is ovoid, with a stout, straight non-deciduous cornutus (seta) attached apically; a semicylindrical endophallite is located along the distal ductus ejaculatorius simplex (Fig. 4).Notably, in some other Thiodia spp. the vesica is reduced and bears a bundle of deciduous, flat, sigmoid cornuti.The female genitalia are with a short oviscapt, the eight segment is sclerotised, adorned with a belt of long, thick setae (Fig. 3 C).The only signum is an elliptical, concave sclerotised plate with minute acanthae (Fig. 3 D), unlike other species from the genus with two strongly invaginated, blade-like signa.
Habitat and biology: The habitat near Hadzhidimitrovo (Fig. 6 A) is a Danubian loess steppe on a