Lethrus (Lethrus) thracicus Král & Hillert, 2018

Král, David, Hillert, Oliver, Drožová, Dana & Šípek, Petr, 2018, Lethrus (Lethrus) thracicus (Coleoptera: Geotrupidae), a new species from the European part of Turkey, Zootaxa 4521 (4), pp. 573-583 : 574-582

Lethrus (Lethrus) thracicus Král & Hillert , new species

( Figs. 1 a–e; 2d, h; 3d, h; 4d, h; 5d; 6; 7)

Type locality. European Turkey, Edirne prov., 18 km E of Edirne, Habiller env., 41°40'27.96"N 26°47'12.35"E, ca 121 m a. s. l.

Type material. European Turkey, Edirne Prov.: Holotype, ♂ (DKCP), “ European Turkey, 26.iv.2011 | Habiller env. | ca 121 m, 41°40'27.96"N 26°47'12.35"E | P. Janšta, D. Drožová & P. Šípek lgt. [printed]” . Paratypes: allotype, ♀ and 1 ♂ ( DKCP) , 2 ♂♂ and 1 ♀ ( OHCB) and 2 ♂♂ ( CUPC) , same data as holotype; 3 ♂♂ ( DKCP) , “TR [= Turcia]—ca 15 Km | e.[east of] Edirne [ca 41°40'N 26°40'E] | 27.3.[19]88 [Walter] Heinz [legit] [handwritten, black ink]” .

Additional material examined. European Turkey, Tekirdağ Prov.: 1 ♂, 1 ♀ (NMPC), Tekirdağ env. [ca 40°59'N 27°30'E], iv.1987.

Description of holotype (♂). Maximally developed (hyperthelic) male with well developed ventral mandible processes ( Figs. 1a, c, e ). Oblong, strongly convex; dorsal surface black, except moderately shiny pronotum almost alutaceous; ventral surface black with fine blue tinge, moderately shiny, claws black-brown; macrosetation black.

Head ( Figs. 1a, c, e ). Labrum bilobed, asymmetrical, right lobe remarkably more developed; surface rugosely and coarsely, shallowly and sparsely punctate, each puncture bearing short recumbent macroseta; anterior margin with dense row of long macrosetae. Clypeus transverse, trapezoidal with anterior angles rounded. Frontal impressions vague, frontal tubercles indistinct. Frontoclypeal suture present only laterally; keels separating eye canthus from frons only slightly developed but distinct, slightly divergent posteriad. Eye canthus exceeding eyes, projecting anterolaterad, almost rectangular, lateral margins divergent posteriad, anterolateral angle rounded, oblique keel above eyes absent. Pleurostomal process evenly arcuate, hardly exceeding ventrolateral mandible outline. Punctation of frons double, consisting of coarse, transversally rugose, regularly and densely distributed punctures, intermixed with fine, irregularly distributed ones; coarse punctures separated by approximately less than their diameter, punctation becoming distinctly sparser posteriad and on occiput; clypeus and eye canthus distinctly rugose.

Mandibles symmetrical, external outline almost semicircular, pointed subapically in dorsal aspect ( Figs. 2a, e ) with maximum width approximately at middle of mandibles length.

Ventral mandible processes ( Figs. 2d, h ; 3d , 5; 4d, h ) weakly asymmetrical, right process slightly more developed than left one and with different angle in lateral aspect. Both processes distinctly longer than length of mandible; base thickened, not exceeding lateral mandibular outline in dorsal aspect, with slightly concave external outline in basal half in frontal aspect; longitudinal keel on base laterally present, straight and approximately parallel to lateral mandibular outline in dorsal aspect, distinctly broader as maximum width of mandibles outline basally; in lateral aspect weakly arcuate, approximately subparallel to lateral mandibular outline, slightly divergent gradually basad approximately from middle of its length. Inferiobasal tooth absent; both processes bent inward aproximately in middle of mandibles length in frontal view; anterior subapical tooth absent; apical emargination absent; apical tooth round.

Pronotum ( Figs. 1a, c, e ) transverse, distinctly broader than base of elytra, broadest just behind middle; margin entirely bordered, slightly crenulate in anterior parts. Anterior corners weakly but distinctly projecting anterolaterad, with angulate outline; lateral margin approximately weakly emarginate anteriorly, than straight to rounded posterior angle; basal margin straight. Punctation of dorsal surface simple, consisting of deep, sparsely and irregularly distributed punctures; punctures separated by approximately two to four their diameters discally, surface near lateral margins considerably shagreened and alutaceous.

Scutellar plate widely triangular, finely shagreened.

Elytra almost semicircular, apices not prominent, each apex forming independent arc. Epipleuron strongly narrowed apicad, epipleural keel not reaching elytral apex. Whole surface alutaceous, finely transversally rugose; striae not indicated, entirely vanishing in rugosities.

Legs. Profemur not armed, protibia with row of eight gradually proximad diminishing external denticles, and with row of tubercles on ventromedial edge.

Male genitalia. Aedeagus with parameres shallowly sinuate distally in lateral aspect ( Figs. 1b , 5d)

Measurements. Total body length 18–24 mm, holotype— 23 mm, allotype— 24 mm ( Figs. 1a, c, d, e ).

Variability in males. Mandible processes in medium developed and underdeveloped (hypothelic) males short, more or less straight with simply rounded to almost acute apically.

Sexual dimorphism. Female ( Fig. 1d ) differ from males as follows: external outline of mandibles almost straight, in apical quarter rounded in dorsal aspect; ventral mandibular process absent; pronotum anterior corners more angulate, pronotum lateral margins broadly rounded, protibia broader, row of tubercles on ventromedial edge less pronounced.

Differential diagnosis. Among the species distributed in the Balkan Peninsula, the new species is most similar and probably closely related to Lethrus (L.) ares Král, Rejsek & Schneider, 2001 , L. (L.) apterus (Laxmann, 1770) and L. (L.) schneideri Král & Hillert, 2013 . Distinguishing features in males are as follow: absence of anterior subbasal tooth of ventral mandibular processes (L. (L.) schaumii Reitter, 1890 and L. (L.) elephas Reitter, 1890 have distinct anterior subbasal tooth); absence of anterior subapical tooth of ventral mandibular processes (L. (L.) halkidikiensis Hillert & Král, 2013, L. (L.) perun Hillert & Král, 2013, L. (L.) raymondi Reitter, 1890 and L. (L.) strymonensis Hillert & Král, 2013 have distinct anterior subapical tooth); presence of approximately symmetrical ventral mandibular processes and regularly rounded or obtuse-angular anterior pronotal angles (L. (L.) fallax Nikolajev, 1975 and L. (L.) liviae Pittino, 2011 have remarkably asymmetrical ventral mandibular processes and strongly produced acute-angular anterior pronotal angle). For characters to separate L. (L.) apterus , L. (L.) ares , L. (L.) s chneideri and L. (L.) thracicus Král & Hillert , new species, see the character matrix ( Table 1). Additionally, these four species exhibit probably a strictly allopatric distribution. Lethrus (L.) thracicus Král & Hillert , new species is restricted to the European part of Turkey (it means the lowland east of the Maritza river); L. (L.) s chneideri is an endemic species of the southernmost slopes of the Rhodope Mountains approximately between the towns of Xánthi and Komotiní ( Greece); L. (L.) ares is known so far only from four spots all situated in the Eridropótamos river basin ( Greece and Bulgaria) and L. (L.) apterus is a widely distributed Pannonian species known from Burgenland ( Austria), Moravia ( Czech Republic) and Serbia in the west to the Don river basin in the east (see e.g., Král et al. 2013, Nikolajev 2003, Bagaturov & Nikolajev 2015 and Chehlarov et al. 2016).

Etymology. Toponymic; the specific name thracicus reflects the Thracian lowlands region where the new species was collected.

Collecting events. All specimens originating from the type locality were collected from an uncultivated field margin and / or pasture with a disturbed surface mostly in places with very sparse herbaceous layer ( Fig. 7 ). It was a sunny day and some specimens were observed to be active on the surface at 11–12 am.

Distribution. European Turkey ( Fig. 6 ).

Remarks. Fairmaire (1866: 257) dealt in his work with the fauna of beetles of Turkey in a broader sense, i.e. of the territory from which the new species above is described. He introduced also the name Lethrus subaeneus from “Asia Mineure”. However, this name was published without any mention of description or reference to it. Thus, according to ICZN (1999; cf. Article 12), we consider the name Lethrus subaeneus Fairmaire, 1866 to be a nomen nudum.

Figures

FIGURES 1a–e. Lethrus (Lethrus) thracicus Král & Hillert, new species (European Turkey, Edirne prov., Habiller env., holotype (male), excepting allotype (female)—d). a—habitus, left lateral aspect; b—aedeagus, dorsal and left lateral view; c, d—habitus dorsal view; e—habitus, left oblique antero-lateral view. Not to scale.

FIGURES 2a–h. Male head in dorsal view. a, e—Lethrus (L.) apterus (Slovakia, Kamenica nad Hronom, DKCP), b, f—L. (L.) ares (Greece, Evros dist., Polía, holotype, NMPC); c, g—L. (L.) schneideri (Greece: Thrace distr., Karydia, holotype, NMPC); d, h—L. (L.) thracicus Král & Hillert, new species (European Turkey, Edirne prov., Habiller env., holotype). Differential characters shown by arrow. Not to scale.

FIGURES 3a–h. Male head in frontal view. a, e—Lethrus (L.) apterus (Slovakia, Kamenica nad Hronom, DKCP), b, f—L. (L.) ares (Greece, Evros dist., Polía, holotype, NMPC); c, g—L. (L.) schneideri (Greece: Thrace distr., Karydia, holotype, NMPC); d, h—L. (L.) thracicus Král & Hillert, new species (European Turkey, Edirne prov., Habiller env., holotype). Differential characters shown by arrow. Not to scale.

FIGURES 4a–h. Male head in left lateral view. a, e—Lethrus (L.) apterus (Slovakia, Kamenica nad Hronom, DKCP), b, f—L. (L.) ares (Greece, Evros dist., Polía, holotype, NMPC); c, g—L. (L.) schneideri (Greece: Thrace distr., Karydia, holotype, NMPC); d, h—L. (L.) thracicus Král & Hillert, new species (European Turkey, Edirne prov., Habiller env., holotype). Differential characters shown by arrow. Not to scale.

FIGURE 6. Sketch map of the Thracian lowlands (parts of Bulgaria, Greece and European Turkey) with marked distribution of Lethrus (L.) ares—red marks, L. (L.) schneideri—yellow marks, L. (L.) thracicus Král & Hillert, new species —blue marks; triangles represent the type localities. Compiled from Král et al. (2001, 2013) and Chehlarov et al. (2016).

FIGURE 7. Type locality of Lethrus (L.) thracicus Král & Hillert, new species. European Turkey, Edirne prov., 18 km E of Edirne, Habiller env., 26.iv.2011 (photo by Petr Šípek).