Limnophora ljubomirovi, Zielke, 2017

Zielke, Eberhard, 2017, Description of a new Limnophora species from Bulgaria (Diptera: Muscidae), Beiträge Zur Entomologie = Contributions to Entomology 67 (2), pp. 319-324 : 320-322

Limnophora ljubomirovi spec. nov.

urn:lsid:zoobank.org:act:BC851ACE-FCBA-482F-800D-70177499A33A

Material examined: Male holotype, Bulgaria, Vurbitsa river bed, Momchilgrad, 41°32'34"N; 25°23'23"E, 239 m, 15.8.2016, leg. E. Zielke.

Description: Head. Ground-colour black. Eyes bare. Frons (fig. 1) slightly dilating from vertex to lunula, at middle 0.47 times as broad as width of head. Frontoorbital plate at level of anterior ocellus about as broad as twice the diameter of anterior ocellus, at anterior margin broader than width of postpedicel. Frontal vitta dilating from top to middle and then getting slightly narrower, frontal triangle visible as a whole only at certain point of view reaching almost anterior margin. Parafacial about evenly broad all over the length, at middle as broad as two third of width of postpedicel. In profile antennae inserted nearly at middle of head, upper mouth margin about in line with profrons. Genal depth below lowest eye margin equal to width of postpedicel. In anterodorsal view fronto-orbital plates greyish-white with a conspicuously brown patch at about middle, extending from second to most posterior frontal seta. Frontal vitta and lower part of frontal triangle, depending on angle of view, dark to almost velvety black, upper part of frontal triangle and the ocellar tubercle greyish white. Face and parafacial from anterior point of view white and shining white respectively; gena and post-occipital surface uniformly greyish at lateral view. All antennal segments black, postpedicel three times as long as wide, tip dorsally with a rounded edge. Arista about twice as long as length of postpedicel, longest aristal hairs about as long as width of postpedicel. Ocellar setae strong, about as long as inner verticals, outer verticals slightly longer than half length of inner verticals and distinctly longer than adjacent postocular setae. Fronto-orbital plate at level of anterior ocellus and above with two distinct reclinate orbital setae (anterior ones are missing but scars are very distinct), one very strong inclinate frontal seta at the lower margin and distinctly above, at about the middle third of frons in the area of the brown patch, two or three weaker frontal setae, one or two short interstitial hairs between the lowest and the upper frontal setae, lower part of fronto-orbital plate, in particular the brown patch with several short setulae outside the frontal setae. Parafacial bare. Vibrissal setae strong and more than twice as long as the surrounding peristomal setae. Lower margin of gena, post-genal and post-occipital surfaces covered with dark hairs. Proboscis shining black; palpus black and slender.

Thorax: Ground-colour grey. Scutum from dorsal point of view (fig. 2) predominantly greyish; presutural part of scutum with a pair of broad brown submedian stripes reaching from neck to posterior presutural dorsocentral seta, each stripe widens in posterior half to an almost square patch which lies about between the presutural dorsocentrals and the posthumeral and presutural setae, at suture two narrow but somewhat broadened brown presutural patches; postsuturally a somewhat shining dark brown transverse band, extending between the wing bases and from suture to about the insertion of second postsutural dorsocentral seta. Basis of brown transverse band, directly at suture with two narrow, crescent-shaped grey patches each one about as broad as distance between the row of postsutural dorsocentrals and the intra-alar setae. A brown crescent like median spot located on scutum directly at scutellar suture. Scutellum with transverse shining dark brown band covering about the basal half of dorsal and lateral surfaces, posterior half dorsally and laterally uniformly grey, ventral surface predominantly dark. Greater ampulla and adjacent area brown, pleura all grey. Anterior and posterior spiracle whitish. Scutum and pleura with some dark setulose groundhairs, hairs of pleura distinctly shorter than those of scutum. Thorax with 0+1 acrostichal setae, the presutural setulae in about four irregular rows; dorsocentral setae 2+3, prescutellar one much longer than anterior one; notopleuron with 2 setae but without additional hairs; 2 intra-alar setae. Scutellum with 1 long apical and 1 long lateral seta, preapical and basal setae weak and only slightly longer than surrounding hair, lateral and ventral surfaces bare. Prosternum laterally with black setulae. Proepimeral area, anepimeron, katepimeron and meron bare. Katepisternals 1+2, the posterior upper one about three times as long as the two other ones. Anepisternum at posterior margin with about 4 stronger setae and few interstitial hairs.

Wing: Membrane hyaline. Basicosta and tegula dark brown; veins at basis yellowish and more distally brown. Costal spine not significantly longer than surrounding costal bristles. Veins bare, radial node dorsally and ventrally with few long setulae, the longest ones about as long as half the length of crossvein r-m or even longer. Crossvein r-m below the point where vein R 1 enters costa, distal crossvein dm-cu sinuous, barely oblique. Vein M 1 slightly curved forward before wing margin (fig. 3). Calypters whitish transparent with white margin and fringe, lower calypter distinctly longer than upper calypter. Haltere predominantly white with a very weak yellowish shade.

Legs: Ground-colour dark, somewhat greyish. Pulvilli about half as long as claws, which are barely half as long as corresponding tarsomere 5. Hind coxa bare on posterior surface. Fore femur with complete rows of posterodorsal, posterior and posteroventral setae, all setae barely as long as depth of femur; fore tibia without posterior seta. Mid femur at basal half with row of anterior setae, the longest one at middle of femur, barely much longer than half width of femur, preapically two strong posterior setae; mid tibia with two posterior setae longer than diameter of tibia. Hind femur with complete row of anterodorsals and at apical fourth with about three anteroventrals, all setae not longer than depth of femur; hind tibia with one anteroventral and one anterodorsal seta about as long as diameter of tibia.

wing-vein M 1 before margin of wing. These and other taxonomic markings lead in the key to Limnophora species ( HENNIG, 1964) to couplet 22 (23) with Limnophora exigua (WIEDEMANN, 1830) (= Limnophora plumiseta STEIN, 1903 ). This species is not recorded yet Abdomen: Ground-colour grey (fig. 4). Posterior half of tergite 1+2 with two paramedian brown patches of almost round shape reaching posterior margin; tergite 3 from anterior to posterior margin with a pair of broad paramedian longitudinal stripes which extend in posterior half laterally forming an L-shaped marking; tergite 4 in posterior half with two paramedian brown patches reaching the posterior margin; tergite 5 only with a median longitudinal stripe not reaching the margins. Tergite 1+2 laterally with several longer setae, tergites 3 and 4 laterally with some longer marginal setae; tergite 5 with a complete row of long discal setae and with short and weak marginals. Sternite 1 bare; sternites 2 to 5 without conspicuous setae, sternite 5 with almost completely straight posterior margin (fig. 5).

Male genitalia: Hypopygium barely pronounced. The species is clearly distinguished by morphological characters from similar species. The determination does not depend on characters of male terminalia. To avoid inflicting damage on the only hitherto available specimen of this species it has been refrained from extracting the genitalia.

Measurements: Length of body about 5.5 mm; length of wing about 5 mm.

Female not known.

Etymology: It is a pleasure to name this species after Toshko Ljubomirov, Ph.D., Associate Professor and curator of the scientific zoological collection of the Institute of Biodiversity and Ecosystem Research, Sofia. I want to express herewith my gratitude for his continuous help and active support when field trips had been planned and conducted, to collect muscids in different localities and biotopes of Bulgaria. The species name ljubomirovi is a noun in the genitive case.

Diagnosis: Limnophora ljubomirovi is in particular characterized by a plumose arista, conspicuous brown patch at the middle of the greyish-white frontoorbital plate and the slightly but clearly curved Limnophora ljubomirovi spec. nov., male holotype. (Fig. 1: frons viewed from anterodorsal (bar = 0.5 mm). Fig. 2: dorsal view of scutum (bar = 1 mm). Fig. 3: dorsal view of right wing with vein M1 slightly curved forward to vein R 4 +5 (bar = 1 mm). Fig. 4: male holotype, dorsal view of abdomen (bar = 1 mm). The anterior half of tergite 1+2 is grey and not as dark, as it appears on the photo. Fig. 5: ventral view of sternite 5 (S) (white bar = 0.2 mm )) .

from Europe, but known from Asia, North Africa and Afrotropical Region. Both species have in common aristal hairs as long as or longer than half the width of postpedicel. Additionally to other differences such as colour of frons and markings of thorax and abdomen these species are clearly distinguished by 2+4 dorsocentral setae and parallel running wing-veins R 4+5 and M 1 in L. exigua and 2+3 dorsocentrals and the apically curved vein M 1 in L. ljubomirovi . Using the newly published keys by GREGOR et al. (2016) which primarily consider Muscidae from Central Europe, the male of L. ljubomirovi leads to couplet 8 with Limnophora triangula (FALLÉN, 1825) . L. triangula is characterized by short hairs on the arista, more or less strongly developed longitudinal stripes on scutum, mid tibia with only one posterior seta and parallel running wing veins R 4+5 and M 1, whereas in L. ljubomirovi the aristal hairs are about as long as width of postpedicel, the markings of scutum and scutellum are transverse, mid tibia has two posterior setae and the mentioned wing veins are apically not parallel. Moreover, there are also differences between the two species regarding colour of head, thorax and abdomen.

The specific pattern of thorax and abdomen of the L. ljubomirovi male lets one think at the first glance of the markings known from females of Limnophora tigrina AM STEIN, 1860 . However, the male of L. ljubomirovi has a postsutural brown transverse band reaching from wing base to wing base, whereas the females of L. tigrina are marked with two distinctly smaller brown patches, which are very similar to the presutural ones.

A slightly curved vein M 1 is also known from species of the genus Neolimnophora SCHNABL which is closely related to the genus Limnophora and which is separated from Limnophora by ventrally and dorsally bare radial nodes. L. ljubomirovi has well developed setae on both sides of the radial node and can also be differentiated from the two known Neolimnophora species by its long aristal hairs, 2 + 3 dorsocentral setae and different body colour and pattern.