A new species of Lathys from Turkey (Araneae, Dictynidae)

Abstract A new species, Lathys ankaraensis sp. n., is described based on the material collected in the Central Anatolia. The new species belongs to the humilis-group. Habitus, as well as copulatory organs of both sexes, are described and illustrated by means of line drawings and digital and SEM photographs. A key for the four Lathys species known in Turkey is also provided.


Introduction
Lathys Simon, 1884 with 45 known species, is one of the largest genera of Dictynidae distributed chiefly in the Holarctic (WSC 2016). So far, three species of Lathys have been reported from Turkey: L. humilis (Blackwall, 1855), L. lehtineni Kovblyuk, Kastrygina &Omelko, 2014, andL. stigmatisata (Menge, 1869) (Bayram et al. 2016). All species were recently redescribed in details by Marusik et al. (2006Marusik et al. ( , 2009a and Kovblyuk et al. (2014). Recent field studies focused on litter sampling revealed one more species new to science. It was found in several localities from woodland habitats in Central Anatolia.
The goal of this paper is to provide a description of the new species together with notes comparing the two sibling species.

Material and methods
Examined specimens were collected from the Central Anatolia region of Turkey by using a litter reducer (Fig. 1). The specimens were preserved in 70% ethanol. Digital images of the copulatory organs were taken with a Leica DFC295 digital camera attached to a Leica S8AP0 stereomicroscope and several photographs were taken in different focal planes and combined using auto montage software. SEM microphotographs were made from dried and sputter coated (by gold) organs by use of a Zeiss Ultra Plus SEM device (Anadolu University, Eskişehir). All measurements are in millimeters.
The following abbreviations were used in the text: Diagnosis. Lathys ankaraensis sp. n. belongs to the humilis species group represented by two species in the West Palaearctic, L. humilis (Blackwall, 1855) and L. nielseni (Schenkel, 1932). It can be distinguished from the congeners by a combination of the following characters: having white guanine spots on dorsum of abdomen (absent in L. nielseni), longer copulatory ducts (Cd) with a series of loops (Figs 18, 24, 39) (single loop in the congeners), partially fused atria (At, separated in L. humilis), wider septum (Se) occupying anterior half of fovea (thin and long in L. humilis), and straight posterior tip of conductor (Tc) (slightly bent in L. humilis, cf. Figs 10 and 14).
Carapace dark greenishbrown. Cephalic region higher than thoracic region. Fovea distinct, blackish. Darkly colored crack-like pattern with indistinct borders apparent around fovea, at the corners of thoracic region and at the rear side of PME. Anterior eyes arranged in almost straight line. Chelicera color as carapace. Anterior surface of chelicera with irregularly distributed blackish setae of varying sizes, raised on small pits. Anterior margin of the cheliceral groove with four teeth, and posterior margin with three. Teeth on posterior margin smaller than anterior teeth, and almost identical in size to each other. Gnathocoxae yellowish brown, longer than wide, with sparsely distributed tiny, blackish, short setae on the surface. Labium trapezoid, slightly wider than long; darker in color compared to gnathocoxae. Sternum yellowish light brown, dark brown at the edges, with blackish setae on the surface varying in size especially towards the edges. Legs greyish light brown, with blackish setae in all segments, especially intense on ventral surfaces.
Posterior part of segments with dark rings. Abdomen oval, with a characteristic pattern. Abdominal pattern forming a blackishbrown longitudinal band starting from the middle of the anterior side, barely reaching to the middle of abdomen, followed by five chevrons on the posterior. A variable dark colored pattern apparent onsides; tends to join with the first chevron at the anterior half. Apart from the specified patterns, dorsal side of abdomen grayish light brown, with variably distributed bright white spots. Ventral side of abdomen generally light in color, usually grayish, brown in some specimens.  Palp as in Figs 8-11, 26-28, 31-35; patella with flat dorsal apophysis located on conical dorsal extension; tibia with three apophyses: ventral (Va), retrolateral (Ra) and dorsal (Da); cymbium conical, its height subequal to half of the length; posterior arm of conductor (Pc) with almost straight tip locked by three tibial apophyses and cymbium; sperm duct makes a loop (Sl) at approximately the 10 o'clock position (Fig. 9).
Females slightly lighter than males. Crack-like blackish pattern on carapace much more distinct in females. Dorsal pattern on abdomen distinct but usually duller in color compared to males. Calamistrum with eight setae, slightly longer than half of metatarsus. Spines lower in number compared to males. For leg measurements see Table 1. Epigyne as in [22][23][24][25][37][38][39][40]fovea (Fo) wide, twice as wide than long, with two partly fused atria (At), septum (Se) located in anterior half of fovea, wide, covered with few setae. Endogyne with small receptacles (Re) and long copulatory ducts forming several coils in two plains, anterior part with one coil (Cl) almost parallel to the epigynal plate, and other coils (Cp) make several loops around receptacles. Natural history. It seems that adult specimens of the new species can be found throughout the whole year. Lathys ankaraensis sp. n. was found exclusively in the litter under pine trees or oak bushes (Fig. 43).
Comments. The first record of the genus Lathys from Turkey has been provided with L. humilis from the Marmara region (Tekirdağ province; European part of Turkey; van Helsdingen 2013). Subsequent records were presented more recently as L. lehtineni and L. stigmatisata respectively from the Aegean (Aydın Province, Danışman et al. 2014) and Central Anatolia (Koçyiğit et al. 2016) regions.
With description of L. ankaraensis, the number of Lathys species known from Turkey has increased to four and number of dictynid species to twenty (Bayram et al. 2016). These numbers are expected to increase in near future as there are species known from the close vicinity such as L. cambridgei (Simon, 1874), L. spasskyi  Andreeva & Tyshchenko, 1969or L. nielseni (Schenkel, 1932, which have a wide distribution in the West Palaearctic. It is worth mentioning that records of L. lehtineni (Danışman et al. 2014) from Aydın and L. stigmatisata (Koçyiğit et al. 2016) from Niğde, Aksaray provinces may refer to another species. According to the original description, L. lehtineni lacks any pattern, but Fig. 3A in Danışman et al. (2014) displays a distinct pattern. A key feature of the male of L. stigmatisata is the conical outgrowth of the palpal patella (Marusik et al. 2009b), and such outgrowth is missing on Fig. 2 in Koçyiğit et al. (2016). Below a key to the species reported from Turkey is provided. Tegulum with a prolateral-anterior thin loop of seminal duct (Fig. 9)  Atrium with a septum (Fig. 41) Copulatory openings small, spaced by approx. 1/2 diameters ..... L. lehtineni -Copulatory openings large, separated by thin septum (Fig. 20) .....L. stigmatisata