Two new species of the genus Timia and a redescription of Timia mongolica (Diptera, Ulidiidae)

Abstract Two new species of the genus Timia Wiedemann, 1824 are described and illustrated. Timia lazebnayae sp. n. from Uzbekistan has yellow body and is similar to Timia gobica Zaitzev, 1982, differing from it only by the entirely yellow flagellomere 1. Timia shatalkini sp. n. from Mongolia has dark body and differs from all other dark-colored representatives of the genus by the cell r4+5 being completely closed, forming petiole at the wing apex. Timia mongolica Zaitsev, 1982 is redescribed and an updated key for yellow-coloured Timia is provided.


Introduction
Timia Wiedemann, 1824 is a Palaearctic genus which includes 60 described species, commonly found in semi-arid and arid regions (Becker 1906;Hendel 1908;Hennig 1940;Zaitzev 1982;Zaitzev 1984a, b;Kameneva 1996Kameneva , 2000Kameneva , 2010Galinskaya 2011Galinskaya , 2014Morgulis and Freidberg 2014). While studying the Ulidiidae material from the collection of the Zoological Institute of the Russian Academy of Sciences, Saint-Petersburg (ZISP), the author came across several specimens of flies, belonging to the two new species described below. Examination of the type material of Timia mongolica Zaitsev, 1982 revealed several disparities between the specimens and the description of the species (Zaitsev 1982); for example, the body appeared to be yellow and not dark brown. The previously unknown female of T. mongolica was found in the collection of ZISP. Therefore, this species is redescribed here and an updated key for the yellow-coloured Timia is provided.

Material and methods
Specimens examined were obtained from or deposited in the collections of the following institutions:

ZISP
Zoological Institute of the Russian Academy of Sciences, Saint-Petersburg, Russia ZMUM Zoological Museum of the Lomonosov State University, Moscow, Russia MNKB Museum für Naturkunde, Leibniz-Institut für Evolutions und Biodiversitätsforschung, Berlin, Germany Morphological terminology and abbreviations generally follow White et al. (1999). Series of photos were taken directly by the Canon EOS 40D camera with Canon MP-E 65 mm lens and then composed with CombineZM software (Hadley 2007). Measurements are provided in millimetres.
Diagnosis. Yellow or black flies. Frons usually with dents and bumps, shiny or almost shiny, sometimes with white microtrichose areas. Antennal grooves deep, oval, well-separated by wide facial carina. Thorax and abdomen shining or shagreened, sometimes almost matt, sometimes with green metallic shine, often with microtrichose areas. Wing hyaline, in some species with dark cells bc, c, sc and apical spot. Male genitalia: epandrium subovoid; surstylus hook-like, sometimes with marked posterodorsal lobe; cerci clearly bilobed; phallus long, coiled and partially flattened divided into two parts, with a pair of sclerotized taeniae ending approximately at its mid-length and another pair of taeniae beginning at phallus middle almost reaching phallus apex; phallus apical half bearing long membranous appendix ("caecum"); distiphallus apex bowed and bearing numerous spurs, and "glans" formed by hooks or lobes surrounding gonopore. Surstylus hook-like, sometimes with marked postero-dorsal lobe. Cerci clearly bilobed. Female terminalia: aculeus moderately long and wide, with short oval cercal unit; three spherical spermathecae with smooth or micropapillose surface. Separation of Timia and Ulidia Meigen, 1826 is difficult. The characters used so far are mainly as follow: frons smooth (in Timia) or dimpled (in Ulidia) (with some exceptions), head and thorax microtrichose (in Timia) or bare (in Ulidia, but some species assigned to Timia have shiny head and thorax, and Ulidia metope Kameneva, 2010 has frons widely microtrichose) (Chen and Kameneva 2009;Kameneva 2010). In addition, species of the genus Ulidia always have entirely black bodies without yellow parts of thorax and abdomen.
Remarks. Adult Timia, as well as many other ulidiids, are attracted to various organic residues (decaying plant tissue, animal corpses, excrements). In arid habitats, the surface of organic residues is quickly covered with a dried crust, under which semiliquid substrate is preserved for a relatively long time. The proboscis of Timia has longitudinal rows of pointed outgrowths located on the labellum; flies make a hole in a crust with these appendages and then penetrate with long tubular appendage of the proboscis into it, absorbing semi-liquid substrate (Zaitzev 1982).
Key to the yellow-bodied species of the genus Timia and Timia shatalkini sp. n.

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Distance between apices of veins R 4+5 and M longer than cross-vein R-M. Scape and pedicel entirely black, contrasting with yellow flagellomere 1 ( Figure 6)   Cell r 4+5 apically completely closed, forming petiole. Parafacialium about half as wide as flagellomere 1. Thorax with microtrichose area on mesonotum forming a medial vitta; thorax light brown, with dark brown lateral spots (mainly on presutural area of scutum) and medial stripes (Figure 2 Diagnosis. Timia lazebnayae sp. n., Timia shatalkini sp. n. and Timia gobica differ from all other Timia species by cell r 4+5 completely closed, forming petiole at wing tip and by parafacialium narrow, almost 0.3 times as narrow as first flagellomere. Timia lazebnayae sp. n. differing from Timia shatalkini sp. n. and Timia gobica by first flagellomere entirely yellow. Timia lazebnayae sp. n. is characterised by body yellow; cell r 4+5 apically completely closed, forming petiole at wing tip; parafacialium less than half as wide as flagellomere 1, and narrower than antennal groove; flagellomere 1 entirely orange.
Description. Male: Head. Frons pale yellow, evenly covered with short and thin brown setulae. Frons with band of weak microtrichosity along eye margin. Ocellar triangle shining black. Lateral part of vertex entirely yellow without dark markings. Occiput pale yellow, covered with short and thin black setulae. Medial occipital sclerite yellow; lateral occipital sclerite yellow, with silver-white microtrichosity. Gena yellow, 0.25 times as low as eye. Postgena yellow. Parafacialium yellow, 0.3 times as narrow as antennal grooves, 0.5 times as narrow as flagellomere 1. Eye as high as wide. Lunula pale yellow. Face yellow, without darkened band along the ventral edge. Clypeus yellow. Scape and pedicel yellow. Flagellomere 1 completely yellow, matted, roundish. Arista yellow. Antennal groove yellow, with thin silver-white microtrichosity. Proboscis yellow, slightly darkened distally. Palpus yellow.
Thorax. Yellow, with pale brown lateral spots (mainly on presutural area of scutum) and with medial stripe. Mesonotum with silver-white microtrichosity, lateral spots and medial stripe. Postpronotum slightly microtrichose. Scutellum nearly shiny, yellow, with short black setulae ventrally. Mediotergite dark brown. Pleura yellow, slightly microtrichose on dorsal edge of anepisternum. Pleura covered with sparse short black setulae. Katepisternum with pale brown spot in ventral portion.
Legs. Entirely yellow. Wings. Hyaline. Cell r 4+5 completely closed, forming petiolate at wing apex. Posteroapical extension of cell bcu 0.2 times as short as width of the cell at its middle. Halter yellow.
Abdomen. Yellow, non-microtrichose. Male genitalia. Surstylus with anteroventral lobe, curved proximally at right angle, bearing two spines at its medial margin; and with short posteromedial lobe covered with setulae ventrally. Cerci tapered at apex, separated by narrow slit, covered with long setulae. Body length, 3.5-3.6 mm. Wing length, 3. Diagnosis. Timia shatalkini sp. n., Timia lazebnayae sp. n. and Timia gobica differ from all other Timia species by cell r 4+5 completely closed, forming petiole at wing tip and by parafacialium narrow, almost 0.3 times as narrow as flagellomere. Timia shatalkini sp. n. differing from Timia lazebnayae sp. n. and Timia gobica by dark brown body. Timia shatalkini sp. n. is characterised by body black; cell r 4+5 apically completely closed, forming petiole at wing tip; parafacialium about half as narrow as flagellomere 1. Thorax with microtrichose area on mesonotum forming a medial vitta; thorax light brown, with dark brown lateral spots (mainly on presutural area of scutum) and medial stripes.
Description. Male: Head. Frons pale brown dorsally, dark brown ventrally, evenly covered with short and thin brown setulae. Frons with band of weak microtrichosity along eye margin. Ocellar triangle shining black. Lateral part of vertex brown. Occiput brown, covered with short and thin black setulae. Medial occipital sclerite brown; lateral occipital sclerite brown, with band of weak microtrichosity along eye margin. Gena 0.25 times as low as eye, brown, with yellow band along eye margin. Postgena brown. Parafacialium yellow, 0.3 times as narrow as antennal groove, 0.5 times as narrow as flagellomere 1. Eye as high as wide. Lunula pale yellow. Face yellow, with darkened band along the ventral edge. Clypeus yellow. Scape and pedicel light brown. Flagellomere 1 light brown proximally, dark brown distally, matt, roundish. Arista light brown. Antennal groove yellow, slightly darkened. Proboscis dark brown. Palpus dark brown.
Thorax. Pale brown, with dark brown lateral spots (mainly on presutural area of scutum) and medial stripe. Mesonotum with silver-white microtrichose medial stripe. Postpronotum with silver-white microtrichosity. Scutellum subshining light brown, with short black setulae over dorsal surface. Mediotergite dark brown. Pleura dark brown, slightly microtrichose on dorsal edge of anepisternum. Pleura covered with sparse short black setulae. Setae. Four small orbital setae (dorsal orbital seta little longer than other ones), one divergent ocellar seta, one divergent postocellar seta, one long convergent medial vertical seta, five divergent postocular setae, one short paravertical seta, and one long divergent lateral vertical seta. Three genal setulae, five postgenal setulae, one long genal seta. Two groups of supracervical setae over occipital foramen.
Legs. Coxa, trochanter and femur dark brown, tibia and tarsus yellow.
Wings. Hyaline. Cell r 4+5 completely closed, forming petiolate at wing apex. Posteroapical extension of cell bcu 0.4 times as long as the width of cell at its middle. Halter yellow.
Abdomen. Dark brown, non-microtrichose. Male genitalia. Surstylus with anteroventral lobe curved proximally at right angle, bears two spines at its medial margin; and with short posteromedial lobe covered with setulae on its ventral side. Cerci tapered apically, separated by narrow slit, covered with long setulae.
Body length

Redescription.
Male: Head. Frons yellow, with large black triangle medially, without microtrichosity, evenly covered with short and thin black setulae. Ocellar triangle shining black. Lateral part of vertex entirely yellow without dark marks. Occiput yellow, medially black, slightly microtrichose close to eye margin, covered with short and thin black setulae. Gena yellow, 0.4 times as low as eye. Postgena yellow. Parafacialium yellow, 0.5 times as narrow as antennal grooves and as wide as flagellomere 1. Eye 1.3 times as high as wide. Lunula yellow. Face yellow, without narrow darkened band along the ventral edge. Clypeus pale yellow, darkened along ventral edge. Scape and pedicel light brown. Flagellomere 1 brown at base, almost black at apex, matted. Arista light brown. Antennal groove yellow, with thin silver-white microtrichosity. Proboscis brown. Palpus brown at base, black at apex.
Thorax. Yellow, with black pattern. Mesonotum with silver-white microtrichose medial stripe. Postpronotum with silver-white microtrichosity. Scutellum subshining yellow, faintly sculptured, with short black setulae over its ventral surface. Mediotergite yellow, with brown spot at the middle. Pleura yellow.
Setae. Four small orbital setae (dorsal orbital seta little longer than other ones), one divergent ocellar seta, one divergent postocellar seta, one long divergent lateral vertical seta, four divergent postocular setae, one short paravertical seta and one long convergent lateral vertical seta. Four genal setulae, eight postgenal setulae, one long genal seta. Two groups of supracervical setae over occipital foramen.
Wings. Hyaline, with yellowish apex. Cell r 4+5 narrowly opened. Apices of veins R 4+5 and M almost in contact. Posteroapical extension of cell bcu 0.3 times as short as the width of cell at its middle. Halter yellow.
Male genitalia. Surstylus with anteroventral lobe curved proximally at right angle, bears two spines at its medial margin; and with short posteromedial lobe covered with setulae on its ventral side. Cerci tapered at top, separated by narrow slit, covered with long setulae.