Research Article |
Corresponding author: Jiří Skuhrovec ( jirislavskuhrovec@gmail.com ) Academic editor: Michael Thomas
© 2017 Jiří Skuhrovec, Miguel A. Alonso-Zarazaga.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Skuhrovec J, Alonso-Zarazaga MA (2017) Revision of the genus Limobius, with the description of a new species (Coleoptera, Curculionidae, Hyperini). ZooKeys 709: 71-85. https://doi.org/10.3897/zookeys.709.14877
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The new species, Limobius winkelmanni sp. n. is described, keyed, and illustrated. This enigmatic new species has seven desmomeres as other Hyperini-species, but according to shape of elytra and aedeagus, which are typical for representatives of Limobius, it is treated in this genus. The actualised key and check-list of Limobius is presented. The taxonomical position and status of the genus Limobius within the tribe Hyperini is also discussed here.
Check-list, Coleoptera , Curculionidae , description, distribution, Europe, Hyperini , key, Limobius , new species, Palaearctic Region, taxonomy
The phylogenetic and taxonomic position of hyperines is still unresolved. In the previous study, hyperines together with Bagoini and Gonipterini were regarded as unplaced tribes in Curculionidae (
Their only unique feature appears to be the specific meshed cocoon spun by the larvae from strands of protein secreted by the Malpighian tubules (
Only the Palaearctic fauna of Hyperini have received recent taxonomic attention.
The genus Limobius is one of the smallest genera, currently including only three known species. All known Limobius species develop on Geraniaceae plants (
In this paper, Limobius winkelmanni sp. n. is described and illustrated. The first author received these specimens from the second author as a probably new species of unknown affinities, and this new species presented a taxonomic mystery which took ten years to solve. This enigmatic new species has seven desmomeres as other Hyperini species, but according to the shape of the prominent humeri and of the aedeagus, which are typical for representatives of Limobius, it is treated here as a member of the Limobius. The taxonomic position and status of Limobius within the tribe Hyperini are also discussed here.
Taxonomy and photographic documentation. Body lengths of all specimens were measured in dorsal view from the anterior border of the eyes to the apex of the elytra, excluding the rostrum. All measurements were measured in dorsal view. Dissected male and female genitalia were studied in glycerine and thereafter mounted dry on the same card as the respective specimen. Photos of genitalia were made using an Olympus BX40 microscope and combined in Zerene Stacker and GIMP2 software. Photos of adults were made with a Camera Canon Powershot A640 and Canon EOS 550D with a macro-objective MP-E 65 mm and combined using CombineZM and GIMP2 software. The terminology of the rostrum and the genitalia follows
Specimen depositories and citations. Specimens are deposited in the following museums and private collections:
HWIC Herbert Winkelmann private collection, Berlin, Germany;
JSKC Jiří Skuhrovec private collection, Praha, Czech Republic;
TGAC Tomasz Gazurek private collection, Warszawa, Poland.
Label data are cited in the description, separate lines on labels are indicated by “/” and separate labels by “//”.
Limobius Schoenherr, 1843: 460 (original description)
Limobius
:
Curculio dissimilis Herbst, 1795: 290 (= Curculio borealis Paykull, 1792: 57).
Body 2.5–4.6 mm; entire body densely covered with appressed scales of different shapes, from scales divided into two lobes to base up to entire scales. Eyes elliptical to oval. Rostrum long to very long, narrow; in dorsal view distinctly longer than its base width (ratio more than 3.00); enlarged anteriorly, tapered to basal third part and afterward almost parallel-sided; in side view slightly curved; as long as pronotum (ratio = 0.95–1.10). Antenna with 6 or 7 desmomeres. Pronotum distinctly wider than long, widest at middle. Elytra with very distinct prominent humeri. Apex of penis enlarged, sometimes partially to the tip, and always without projecting setae. Apodeme of sternite VIII in females relatively long, with distinct long lateral arms; plate wide, not very well sclerotized, upper part not connected and bearing apically many distinct setae.
These weevils occur in warm and dry habitats (calcareous hillsides, vineland, steppe, sandy habitats, meadows, clearings), and in mesophilic or moderately damp habitats of floodplains and hillsides (natural meadows) (
The genus Limobius is mostly distributed in the western part of Europe and North Africa. Two taxa are known only from southern France. The only widespread taxon is L. borealis borealis, distributed in the whole western Palaearctic region, from Portugal to North Africa and eastwards to Iran (
Altos de San Juan near El Escorial (Spain, limit between the provinces of Madrid and Ávila, 40°37'33.92"N 4°8'29.45"W).
Holotype ♂: ‘Escorial / Puerto [printed label] // Altos de / San Juan [handwritten label] // Altos de S. Juan / debajo de pequeñas / piedras con terreno / de esta composición [translation: Altos de S[an] Juan (S. = San), under small stones with a ground of this composition. i.e., a stony or gravelly ground] [handwritten label]’ (
(Figs
Head (Fig.
Antennae (Figs
Pronotum (Fig.
Elytra (Fig.
Mesoventer. Mesoventral process narrow, not visible in lateral view.
Legs. Femora slightly inflated at middle; profemora almost as wide as rostrum; mesofemora and metafemora slightly slenderer. Tibiae apically widened. Meso- and metatibia straight, protibia slightly curved outwards. All tarsi similar; tarsomere 1 elongated, almost two times longer than tarsomere 2; tarsomere 2 almost squared, slightly widened at apex; tarsomere 3 triangular, distinctly bilobed almost to base; tarsomere 5 distinctly longer than tarsomere 1, slightly widened in apex. Claws free (not connate at base).
Abdomen. Abdominal ventrites 1–2 approximately of the same length, but twice the length of each abdominal ventrite 3 or 4; abdominal ventrite 5 almost of the same length as abdominal ventrites 1–2. Suture between abdominal ventrites 1 and 2 distinctly sinuous medially and shallow; other sutures straight, wide and deep.
Sexual dimorphism. Females slightly larger with more rectangular elytra (ratio length to wide of elytra = 1.4) than males (ratio = 1.35). Protibiae incurved in males and nearly straight in females. Abdominal ventrite 1 with a distinct depression in males but not in females. Apical abdominal ventrite with shallow medial impression in males. No differences in ratios of rostral length, pronotal length and width.
Male genitalia. Penis (Fig.
Female genitalia. Apodeme of sternite VIII relatively long, with distinct long lateral arms; plate starting near apical fifth of apodeme, at apex Y-shaped (Fig.
Limobius winkelmanni sp. n. is variable in body length: 4.2–4.6 mm (length of the holotype 4.4 mm). Colouration of pronotal and elytral vestiture may vary partially (see Description). No genitalic variations were observed.
This species is absolute unique not only in this genus, but also in whole tribe Hyperini. The species is characterized by the antenna with seven desmomeres (Fig.
The new species is named after a close friend of the authors, Herbert Winkelmann (Berlin, Germany), who mentored the first author in Hyperini taxonomy and biology.
Unfortunately, the host plant or any other biological data is not known. Weevils were collected probably at the beginning of the 20th century. We know only an exact locality of this weevil: Alto San Juan near Escorial – ca 35 km NW from Madrid, which is located in the mountains, 1734 m a.s.l. All known Limobius species develop on plants of the family Geraniaceae, but we cannot be sure if this will also be true with this new species. Additionally, its larval strategy could be different (see Introduction). Limobius borealis develops in the unripe flower heads of Geranium species instead as typical ectophagous Hyperini larva on the leaves or flowerhead. The main reason in this different strategy of Hyperini larvae is the size of larva, and Limobius winkelmanni sp. n. is distinctly larger than all Limobius species. However, its body length is still similar in size to some small Hypera species (e.g., H. nigrirostris), whose development is also in the unripe flower heads.
Central Spain (provinces Madrid and Zaragoza).
1 | Desmomeres 7 (Fig. |
L. winkelmanni sp. n. |
– | Desmomeres 6 (Fig. |
2 |
2 | Elytral scales entire, not divided in two lobes (Fig. |
L. mixtus |
– | Elytral scales divided in two lobes apically, the emargination reaching at least midlength of each scale (Fig. |
3 |
3 | Elytra only with a few projecting setae. (Fig. |
L. borealis arvernus |
– | Elytra with numerous projecting setae (Figs |
|
4 | Pronotum widest behind midlength, near to base; lateral stripe of scales on each margin yellow (Fig. |
L. dureti |
– | Pronotum widest at midlength, lateral stripe of scales on each margin white (Fig. |
L. borealis borealis |
L. borealis borealis (Paykull, 1792) western Palaearctic region
L. borealis arvernus Tempère, 1972 southern France
L. dureti Tempère, 1957 southern France
L. mixtus (Boheman, 1834) western Europe, Malta; Africa: Morocco, Libya
L. winkelmanni sp. n. central Spain
Whereas identification of the species is, in contrast to the majority of other Hyperini genera, quite easy, recognition of the genus Limobius within the tribe Hyperini has recently become a rather difficult matter. Hitherto, the number of desmomeres has been the only one mentioned differential character between genera Hypera and Limobius. This enigmatic new species L. winkelmanni sp. n. has seven desmomeres as other Hyperini-species, but the prominent humeral angles and the shape of the apical part of penis, which are typical of representatives of Limobius, compels us to place it in the genus Limobius. Consequently, the taxonomical position and status of Limobius within the tribe Hyperini has also to be discussed here.
The character of the number of desmomeres has high variability also within different genera in many weevil groups (e.g. Tychius (
Taxonomic positions and relatives of genera, subgenera and species-groups within the tribe Hyperini (including presently three apparently monophyletic groups, the Holarctic Hyperina with ca. 400 species, the circumtropical Cepurina with ca. 50, and the Australian/Pacific unnamed group with ca. 45 species) are completely unknown, and only a detailed morphological revision of the whole group and a molecular phylogeny may resolve these problems. The status of several genera and subgenera is very weak and the complete revision of this still unapproachable tribe, as well as a new evaluation of the characters used for the genus Limobius by
The study of Jiří Skuhrovec was supported by a grant from the Ministry of Agriculture (Mze ČR) RO0416 and a SYNTHESYS (ES-TAF-3511). Miguel A. Alonso-Zarazaga was partly supported by project CGL2015‐66571‐P (MINECO/FEDER) (Ministerio de Economía y Competitividad, Spain). Special thanks to Jon Cooter (Oxford, UK) for linguistic help on the manuscript.