Lethrus (Paralethrus) bituberculatus impressifrons Ballion, 1870

Lethrus impressifrons Ballion, 1870: 336 (original description, type locality: “Tschemkent”); Solsky 1876: 373 (synonymized with Lethrus laevigatus Ballion, 1870).

Lethrus laevigatus v. impressifrons: Reitter 1890: 292 (key, description).

Lethrus (Autolethrus) laevigatus var.? impressifrons: Semenov 1892: 237 (classification); Boucomont 1912: 37 (catalogue); Winkler 1929: 1041 (catalogue).

Lethrus (Autolethrus) Hauseri Reitter in Hauser 1894: 44 (original description, type locality: “Turkestan, Tschimgan”).

Lethrus (Autolethrus) Hauseri: Boucomont 1912: 37 (catalogue); Winkler 1929: 1041 (catalogue).

Lethrus (Autolethrus) hauseri: Semenov 1934: 1396 (distribution); Semenov & Medvedev 1936: 87 (redescription, key, classification, distribution, iconography: Tab. 2 Fig. 36, Tab. 5 Fig. 103, Tab. 7 Fig. 166, Tab. 9 Fig. 214, Tab. 10, Fig. 270, Tab. 11 Fig. 304; Skopin 1955: 152 (characteristics compared).

Lethrus hauseri: Nikolajev 1974: 81 (synonymized with L. bituberculatus impressifrons Ballion, 1870).

Lethrus (Autolethrus) hauseri hauseri: Nikolajev 1969: 529 (classification, redescription, iconography: Figs. 20–23).

Lethrus (Autolethrus) eous Semenov 1894: 484, 522 (original description, type locality: “Dshungaria, Kuldsha”).

Lethrus (Autolethrus) eous: Boucomont 1912: 37 (catalogue); Winkler 1929: 1041 (catalogue); Semenov 1934: 1396 (distribution); Semenov & Medvedev 1936: 87 (redescription, key, classification, distribution, iconography: Tab. 2 Figs. 37, 38, Tab. 5 Fig. 104); Skopin 1955: 152 (characteristics compared); Nikolajev 1969: 529 (synonymized with L. hauseri hauseri Reitter, 1894).

Lethrus (Autolethrus) jacobsoni Semenov & Medvedev 1935: 285 (original description, type locality: “Turkestan, prov. Syrdarjens”).

Lethrus (Autolethrus) jacobsoni: Semenov & Medvedev 1936: 87 (redescription, key, classification, distribution, iconography: Tab. 2 Figs. 34, 35, Tab. 5 Fig. 102, Tab. 7 Fig. 165, Tab. 9 Fig. 213, Tab. 10 Fig. 269, Tab. 11 Fig. 303); Skopin 1955: 152 (characteristics comparred); Nikolajev 1969: 529 (synonymized with L. hauseri hauseri Reitter, 1894).

Lethrus jacobsoni: Protzenko 1972: 7 (distribution).

Lethrus (Autolethrus) nigroaeneus Skopin 1955: 150 (original description, iconography, Figs. 11–14, type locality: south Kazakhstan, Karschan Tau Mts.).

Lethrus (Autolethrus) nigroaeneus: Nikolajev 1969: 529 (synonymized with L. hauseri hauseri Reitter, 1894).

Lethrus (Autolethrus) bituberculatus impressifrons: Nikolajev 1974: 81 (classification).

Lethrus (Lethrus) bituberculatus impressifrons: Nikolajev 1987: 45 (classification, distribution); Krajčík 2012: 142 (catalogue).

Lethrus (Paralethrus) bituberculatus impressifrons: Nikolajev 2003: 199 (classification, distribution, iconography: Fig. 143 Nr. 4, Fig. 145 Nr. 5). Hillert 2004: 827 (redescription, distribution, key, iconography: Figs. 1–3, 17–18, 26–27); Král & Nikolajev 2006: 94 (catalogue); Bagaturov & Nikolajev 2015: 312 (note, distribution); Nikolajev et al. 2016: 51 (catalogue); Schoolmeesters 2020 (online catalogue).

Lethrus (?) mediocris: Fairmaire, 1892: CXXII (122) (original description); Král & Nikolajev 2006: 94 (catalogue); Nikolajev et al. 2016: 51 (catalogue, species incertae sedis).

Lethrus (Autolethrus) mediocris: Boucomont 1912: 37 (catalogue).

Type material examined. Lectotype Ô (here designated) (MNHN) “ Lethrus mediocris / Faim. 1892 [hw] // Museum Paris / 1906 / coll. L. Fairmaire [p] // Lethrus mediocris Ô / Fairmaire / Holotypus / Det. R. Pittino 1990 // Lethrus bituberculatus / impressifrons Ball. / det. O. Hillert 2010 [p, hw] // Lethrus mediocris / Fairmaire, 1892 Ô / Lectotypus / O. Hillert des. 2023 [p]”.

Additional material examined (21 specimens). Uzbekistan, Circik, 4.–7.7.91, M. Valenta leg., 1Ô, 5♀♀ (ZSM, ex. coll. O. Hillert); UDSSR, Samarkand, Aman-Kutan [patria falsa], 15.05.[19]86, Paulus leg., 2ÔÔ (ZSM, ex. coll. O. Hillert); E. Uzbekistan, Tashkent arl. Karzhantau Mts., 26.05.1997, 1Ô (ZSM, ex. coll. O. Hillert); Talkent-Aktau, 03.07.1991, 1, Kletetka leg., 2ÔÔ, 2♀♀ (ZSM, ex. coll. O. Hillert); E. Uzbekistan, Tashkent, Karzhantau Mts., Aktash, 27.05.1997, 1Ô (ZSM, ex. coll. O. Hillert); UDSSR, Uzbekistan, Tashkent Tshimgan, 1800 m, 01.05.1977, J. Novodný, leg., 1Ô (ZSM, ex. coll. O. Hillert); Uzbekistan, Tashkent, Aktash, 10.05.86, Paulus leg., 1Ô, 1♀ (ZSM, ex. coll. O. Hillert); NW Tian-Shan, Pskem Mts. near Nanai, Aksar-Sai, h- 1400 m, 02. V.1995, 1Ô (ZSM, ex. coll. O. Hillert); Tian-Shan, Ugam Mts. Range, Nauvalisay river, 8.–10. V.2000, Tikhonov A., 1Ô (ZSM, ex. coll. O. Hillert); Kuraminsky mt., Kamtshik pass, 23.05.1996, 1100m, 2ÔÔ (ZSM, ex. coll. O. Hillert).

Remarks. The type specimen of L. mediocris Fairmaire, 1892 (MNHN) was labelled as a holotype by R. Pittino in 1990. It is an assumption of a holotype, so according to recommendation 73F of the code here sets this specimen as a lectotype.

The lectotype of L. mediocris has the following characteristics: Dorsal surface of mandibles with distinct transversal carina, reaching not to mandibular outline; frontal edge of profemur without tooth or elevation at middle of length; both mandibles with distinct appendices, weakly asymmetric, left side with subapical tooth at front, right side with weak medial tooth on inner side; punctation on pronotum dense by one of their diameter approximately, shallow midline visible. We recognized that this specimen belongs to the subgenus Paralethrus . This subgenus was reviewed by Hillert (2004), and a great number of specimens were studied.

The morphological characteristics between L. mediocris and L. (P.) bituberculatus impressifrons are identical. The type locality of L. mediocris is extreme broadly formulated but included the type locality of L. (P.) b. impressifrons . In our opinion, L. mediocris is identical with L. (P.) b. impressifrons Ballion, 1870 on the basis of the external characteristics.

We are now able to establish the following synonymy: Lethrus (Paralethrus) bituberculatus impressifrons Ballion, 1870 = Lethrus mediocris Fairmaire, 1892, new synonym .