Кавказский энтомол. бюллетень 12(1): 111–116 © CAUCASIAN ENTOMOLOGICAL BULL. 2016


The genus Gunarus Des Gozis, 1886 belongs to the subtribe Cylindrinotina (Coleoptera: Tenebrionidae: Helopini)

Род Gunarus Des Gozis, 1886 относится к подтрибе Cylindrinotina (Coleoptera: Tenebrionidae: Helopini)

M.V. Nabozhenko1, B. Keskin2, K.D. Dvadnenko3, N. Alpagut Keskin2 М.В. Набоженко1, Б. Кескин2, К.Д. Двадненко3, Н. Альпагут Кескин2

1Caspian Institute of Biological Resources of Dagestan Scientific Centre of Russian Academy of Sciences, M. Gadzhiev str., 45, Makhachkala, Republic of Dagestan 367000 Russia. E-mail: nalassus@mail.ru

2Ege University, Bornova-Izmir 35100 Turkey. E-mail: bekir.keskin.phd@gmail.com

3Institute of Arid Zones of Southern Scientific Centre of Russian Academy of Sciences, Chekhov str., 41, Rostov-on-Don 344006 Russia. E-mail: dvadnenko@ssc-ras.ru

1Прикаспийский институт биологических ресурсов ДНЦ РАН, ул. М. Гаджиева, 45, Махачкала, Республика Дагестан 367000 Россия

2Эгейский университет, Борнова – Измир 35100 Турция

3Институт аридных зон ЮНЦ РАН, пр. Чехова, 41, Ростов-на-Дону 344006 Россия

Key words: Coleoptera, Tenebrionidae, Helopini, Gunarus, subtribal position, new combinations, morphology. Ключевые слова: Coleoptera, Tenebrionidae, Helopini, Gunarus, положение в подтрибах, новые комбинации, морфология.


Abstract. The genus Gunarus Des Gozis, 1886 is transferred from the subtribe Helopina to the subtribe Cylindrinotina (Tenebrionidae: Helopini) based on the structure of male aedeagus and presence of posterior ventral grooves of lower aspect of eye in the type species Gunarus hirtulus (Reiche, 1861). New combinations are established: Stenohelops (Stenomaleis) gayirbegi (Nabozhenko et Keskin, 2009), comb. n. (from Gunarus), Stenohelops (Stenomaleis) korkutelensis (Nabozhenko et Keskin, 2009), comb. n. (from Gunarus) and Ectromopsis ovipennis (Allard, 1877), comb. n. (from Gunarus). The species Gunarus arenicola Antoine, 1949 and G. bremondi Antoine, 1949 must be transferred to the subtribe Helopina but its generic position is unknown. Generic position of other 7 Gunarus species must be revised accordingly to the position of the type species G. hirtulus in the system of the tribe Helopini. Key to similar genera Nalassus, Gunarus, Ectromopsis, Xanthomus is given.

Резюме. Род Gunarus Des Gozis, 1886 переведен из подтрибы Helopina (Tenebrionidae: Helopini) в подтрибу Cylindrinotina на основании строения эдеагуса самца и наличия вентральных бороздок, отходящих от нижнего края глаз, у типового вида Gunarus hirtulus (Reiche, 1861). Устанавливаются новые комбинации: Stenohelops (Stenomaleis) gayirbegi (Nabozhenko et Keskin, 2009), comb. n. (из Gunarus), Stenohelops (Stenomaleis) korkutelensis (Nabozhenko et Keskin, 2009), comb. n. (из Gunarus) и Ectromopsis ovipennis (Allard, 1877), comb. n. (из Gunarus). Виды Gunarus arenicola Antoine, 1949 и G. bremondi Antoine, 1949 должны быть переведены в подтрибу Helopina, но пока не установлено, в какой род. Родовая принадлежность

других 7 видов, относимых к Gunarus, должна быть пересмотрена согласно положению G. hirtulus в системе трибы Helopini. Дана определительная таблица для схожих родов Nalassus, Gunarus, Ectromopsis, Xanthomus.

Introduction

The genus Gunarus Des Gozis, 1886 was erected for the species Helops hirtulus Reiche, 1861 described from Algeria. Later several species from Southern Europe and Northern Africa were added to the genus [Reitter, 1922; Grimm, 1981; Nabozhenko, Keskin, 2009]. Some species previously included in the genus Gunarus were transferred to the genus Ectromopsis Antoine, 1949 [Nabozhenko, 2005]. Up to the present time the genus includes 13 species distributed in the Mediterranean region [Nabozhenko, Löbl, 2008; Nabozhenko, Keskin, 2009; Castro Tovar, 2016]. The genus is problematic (despite the small number of species), because the main diagnostic character is still the body size and comparative length of antennae [Antoine, 1949].

Antoine [1949], based on the structure of male genitalia divided the tribe Helopini into two group. The first group included the species with ‘helopioid’ aedeagus: apical piece with short strong backward spines and long alae (as extensions of ventral side of apical piece), which completely covered ventral side of the basal piece. The second group united the species with ‘nalassoid’ aedeagus: apical piece without spines, alae short, not completely covered ventral side of basal piece. Gunarus hirtulus and two Moroccan species G. arenicola Antoine, 1949 and


image


Figs 1–4. Gunarus hirtulus, habitus, details of structure.

1 – male, dorsal view; 2 – male, ventral view; 3 – head, lateral view; 4 – right protarsus. Arrow shows ventral groove. Рис. 1–4. Gunarus hirtulus, габитус, детали строения.

1 – самец дорсально; 2 – самец вентрально; 3 – голова, вид сбоку; 4 – правая передняя лапка. Стрелкой показана вентральная бороздка.


G. bremondi Antoine, 1949 were included in the first group but Antoine figured only the last two species having apical piece with backward spines.

Subsequently Español [1956] separated the tribe Cylindrinotini (now the subtribe Cylindrinotina) for Antoine’s second group. The genus Gunarus was included in the tribe Helopini sensu Español (now the subtribe Helopina). Later Español and Comas [1989: fig. 2] incorrectly figured and interpreted an aedeagus of G. hirtulus with spines on apical piece and short alae (extensions of apical piece), which did not cover the basal piece. Really representatives of the subtribe Cylindrinotina have short setae which are directed forward, while species of the subtribe Helopina have thick or thin spines which are directed backwards [Nabozhenko et al., 2016b].

The study of a male of Gunarus hirtulus from Algeria allowed to revise the position of the genus Gunarus in the system of the tribe Helopini.


Material and methods

The study is based on the examination of adult beetles from Zoological Institute of Russian Academy of Sciences (ZIN, St. Petersburg, Russia), Hungarian Natural History Museum (HNHM, Budapest, Hungary), Zoological Department of Ege University (ZDEU, Izmir- Bornova, Turkey; specimens of Nalassus). Scanning electron microscopy was performed in the analytic laboratory of Institute of Arid Zones of Southern Scientific Centre RAS with the SEM EVO-40 XVP (LEO 143OVP). We also used Zeiss Supra 55VP Field Emission Scanning Electron Microscope in MEİTAM (Mersin University, Yenişehir, Turkey) and SEM Quanta 250 (Izmir Institute of Technology, Urla, Turkey) for SEM images.

Terms of structure of male aedeagus are taken from Matthews and Bouchard [2008].

Gunarus hirtulus (Reiche, 1861) (Figs 1–8)

Material. 1with label: “Helops (Gunarus) hirtulus Rche Alger” (ZIN).

Brief redescription. Male. Body small (length 4 mm), robust, ochreous, shiny. Head and pronotum covered with suberected hairs, elytra covered with long erected hairs. Ventral side pubescent with recumbent hairs. Lower aspect of eye with a deep posterior ventral groove. Prothoracic hypomera with smooth wrinkles and distinct punctation. Elytra with deep strial punctures without long setae; interstriae with only one line of deep punctures, each puncture with long erected setum. Interstria 8 not more convex apically than other ones, connected with 2nd interstria (not with elytral margin) on apex. Coeloconic sensilla are absent on elytra. Pro- and mesotarsi widened (Figs 1, 4). Aedeagus of male is ‘nalassoid’, weakly sclerotised (Figs 5, 6): apical piece with laterally flattened keel on apex, without backward spines, only with sparse punctation and apically directed very small and short seta in each puncture; alae as extensions of apical piece short, basal piece not covered ventrally; medial piece with narrowly rounded apex and two not connected baculi. Gastral spicula without processes on lobes and rods (Fig. 7). Inner male sternite VIII weakly sclerotized, without additional strongly sclerotized areas (Fig. 8).


image


Figs 5–8. Gunarus hirtulus, male genitalia and terminalia.

5 – aedeagus, ventral view; 6 – aedeagus, lateral view; 7 – gastral spicula; 8 – inner sternite VIII. Scale bar 1 mm.

Рис. 5–8. Gunarus hirtulus, гениталии и терминалии самца.

5 – эдеагус вентрально; 6 – эдеагус латерально; 7 – гастральная спикула; 8 – внутренний стернит VIII. Масштабная линейка 1 мм.


Discussion

The genus Gunarus belongs to the subtribe Cylindrinotina by the presence of posterior ventral grooves on lower aspect of eye and structure of male aedeagus. These ventral grooves are typical only for the genera of the subtribe Cylindrinotina: Cylindrinotus Faldermann, 1837, Nalassus Mulsant, 1854, Stenomax Allard, 1876, Odocnemis Allard, 1876, Armenohelops Nabozhenko, 2002, Eustenomacidius Nabozhenko, 2006, Microdocnemis Nabozhenko et Keskin, 2010, Idahelops Keskin et Nabozhenko, 2012, Taurohelops Keskin et Nabozhenko, 2015.

The structure of aedeagus relates Gunarus with ‘nalassoid’ genera of the tribe Helopini, which are represented in Western Mediterranean by the genera Nalassus, Xanthomus Mulsant, 1854 and Ectromopsis Antoine, 1949. Gunarus hirtulus is also psammophilous supralitoral species as the representatives of two last genera. Español [1953] noted that this species inhabits marine zone and was collected under Thymus.

All three genera of darkling beetles (Ectromopsis, Xanthomus and Gunarus) are morphologically very similar. Xanthomus as probably derivative of the genus Ectromopsis, is more specialized group and has some characters related to the thickness of the sand they inhabit: yellow, sometimes weakly translucent body, more or less flattened protibiae, erected hairs on outer margin of protibiae (sometimes meso- and metatibiae), sometimes pubescent elytra. Gunarus hirtulus also has specialized characters for psammobionts: body ochreous or light-brown, pubescent. Gunarus has not coeloconic sensilla on elytra unlike most


image

Figs 9–13. Nalassus and Ectromopsis, details of structure.

9 – N. plebejus (Küster, 1850), head, ventral view; 10 – E. tantilla, the same; 11 – N. adzharicus Nabozhenko et Dzhambazishvili, 2001, elytra with trichoid and coeloconic (arrow) sensilla; 12 – E. tantilla, elytral coeloconic sensillum; 13 – E. tantilla, elytral trichoid sensillum.

Рис. 9–13. Nalassus и Ectromopsis, детали строения.

9 – N. plebejus (Küster, 1850), голова вентрально; 10 – E. tantilla, то же; 11 – N. adzharicus Nabozhenko et Dzhambazishvili, 2001, надкрылья с трихоидными и целоконическими (стрелка) сенсиллами; 12 – E. tantilla, целоконическая сесилла надкрылий; 13 – E. tantilla, трихоидная сенсилла надкрылий.


Helopini [Nabozhenko et al., 2016a], that also relates with sand inhabitation.

The disjunctive distribution of Ectromopsis indicates relict range of this genus. Ancestral species (Nalassus at least is known from Eocence Baltic amber [Nabozhenko et al., 2016c]) of the genus were associated with the coast of Paratethys and Mediterranean basins [Nabozhenko, 2011]. Representatives of this genus are distributed near the Mediterranean Sea in the western part of generic range: E. mendizabali Cobos, 1953 is known from Almeria;

E. politicollis (Allard, 1876) from drying up reservoir (sebha) on Tell Atlas plateau; E. bulgarica (G.S. Medvedev et Angelov, 1981) from Struma River basin; E. ovipennis (Allard, 1877) from watershed between Nestos and Struma rivers in the lower reaches. Other species of Ectromopsis relate with relict continental reservoirs in the eastern part of range: E. tantilla (Ménétriés, 1848) is distributed in Northern Caspian Region; E. bogatschevi (Iablokoff- Khnzorian, 1957) is known from Ararat plain between Sevan Lake and Aras River; Ectromopsis sp. from sand dunes of relic Eğirdir Lake.

Considering the information above some species must be excluded from the genus Gunarus. Two species described from Turkey [Nabozhenko et Keskin, 2009] belonging to

the genus Stenohelops Reitter, 1922: Stenohelops gayirbegi (Nabozhenko et Keskin, 2009), comb. n. and Stenohelops korkutelensis (Nabozhenko et Keskin, 2009), comb. n. have ‘helopioid’ male aedeagus and female genital tubes, small, strongly shining body, developed humoral angles as other Stenohelops. Unlike Gunarus, turkish Stenohelops inhabit mountain landscapes and live on trees (Juniperus excelsa, Quercus coccifera). These two species must be included in the subgenus Stenomalies Español, 1957 by the wrinkled prothoracic hypomera.

Gunarus ovipennis (we studied one specimen from Greece by Ottó Merkl) has typical characters of the genus Ectromopsis: dark brown body with metallic shine, absence of posterior ventral groove in lower aspect of eye, presence of coeloconic elytral sensilla. As a result, the new combination is established: Ectromopsis ovipennis comb. n.

Unfortunately we did not study other species included in the genus Gunarus, but it is clear from figures and descriptions that G. bremondi and G. arenicola belong to the subtribe Helopina and must be excluded from this genus. The species Gunarus kaszabi (Grimm, 1981) belongs to ‘nalassoid’ group according to the description and images [Grimm, 1981], however its generic position must be corrected considering characters of vertex and


Table 1. Composition of the genus Gunarus. Таблица 1. Состав рода Gunarus.


image


structure of 8th interstria on apex. The species Gunarus tingitanus Allard, 1877 requires the study of type material and designation of lectotype, because 3 syntypes of this species (site of Muséum National d’Histoire Naturelle (Paris, France): https://science.mnhn.fr/taxon/species/ nalassus/tingitanus#allard%2C_1877) belong to 2 different species and at least one of them is Nalassus. Antoine [1949] figured ‘helopioid’ aedeagus for this species. Finally, three from seven remaining species, G. lapidicola (Küster, 1850),

  1. parvulus Lucas, 1846 and G. nodicornis Reitter, 1922, also must be revised.

    Recently Castro Tovar [2016] in the review of Spanish Gunarus added a new ‘nalassoid’ species to the genus and resurrected G. laeviusculus Kraatz, 1883 from the junior synonym of G. tingitanus. As a result, the polyphyletic genus Gunarus includes 9 species from different subtribes (Table 1).

    Thus, further descriptions and revision of the genus Gunarus must (is necessary) considering the position of the type species Gunarus hirtulus in the system of the tribe Helopini.

    Key to the ‘nalassoid’ genera of Western Mediterranean region

    3(6). Lower aspect of eye has a posterior ventral groove (Figs 3, 9). Elytra with or without coeloconic sensilla.

    4(5). Elytral interval 8 convex on apex and connected apically with elytral margin. Winged beetles (wings can be well developed or reduced and very small). Elytra with multipunctured interstriae and coeloconic sensilla (Fig. 11). Male pro- and mesotarsi not widened (only N. laevioctostriatus have widened tarsi) ............

    ................................................................................ Nalassus

    5(4). Elytral interval 8 not convex on apex and connected with 2nd interval apically. Wingless beetles. Elytral interstria only with one line punctures and only long erected trichoid sensilla in interstrial puncture line (Figs 1, 2). Male pro- and mesotarsi widened, transverse (Fig. 4) ................................................. Gunarus

    6(3). Lower aspect of eye without posterior ventral groove (Fig. 10). Wingless beetles. Elytra with trichoid and coeloconic sensilla (Figs 12, 13).

    7(8). Body dark-brown, strongly shining, often with metallic shine. Protibiae not flattened or subfossorial. Tibia with recumbent hairs on outer margin. Male antennae often thickened .............................................. Ectromopsis 8(7). Body yellow, moderately shining, without metallic shine. Protibia less or more flattened, often

    subfossorial. At least protibiae with erected hairs on outer margin. Male antennae not thickened ................

    ............................................................................ Xanthomus

    Acknowledgements

    We thank to Süphan Karaytuğ and Seher Kuru (Mersin University, Turkey) for SEM images. The authors appreciate Ottó Merkl (HNHM) for the provided material on Ectromopsis ovipennis. We also thank to Dirim Şendoğan (Ege University, Turkey) for linguistic comments.

    The study was supported partially by the Ege University (113 BIL 010), grant of the Russian Foundation for Basic Research 15-04-02971А and Russian State Research Project No. 01201363187. Specimens of Nalassus included in this study are part of the collected and sequenced material of a molecular systematic research project (TBAG-Project No: 112T445).

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