A Taxonomic Revision of the Weevil Genus Hypoglyptus Gerstaecker, 1855 (Coleoptera Curculionidae)

Abstract

The genus Hypoglyptus Gerstaecker, 1855 is herein revised for the first time. Based on adult morphological characters, five species are recognized as valid: Hypoglyptus conspersus (Leonhard, 1912) (Greece), H. elegans (Brullé, 1832) (Greece, Albania), H. gracilis Kiesenwetter, 1864 (Greece), H. graecus (Pic, 1902) (Greece), H. heydeni Faust, 1889 (Greece, Syria, Turkey). For this last species a lectotype is designated. Hypoglyptus pictus Gerstaecker, 1855 is proposed as n. syn. of H. elegans (Brullé, 1832). Male and female genitalia have been examined and are illustrated for the first time. The five species are very similar to and separable from each other by a few subtle differences in the shape, the sculpture, and the vestiture of the pronotum and elytra and in the more or less toothed femora. On the basis of morphological characters, the genus Hypoglyptus, previously incertae sedis in Curculionidae, is here tentatively placed in the tribe Smicronychini of the subfamily Curculioninae.

1. Introduction

The genus Hypoglyptus was described by Gerstaecker [1] for his species H. pictus from Corfu (Greece). Gerstaecker stated that his new genus seemed phenotypically intermediate between Hylobius Germar, 1817 and Erirhinus Schoenherr, 1825 (currently a synonym of Notaris Germar, 1817) based on the shape of the head (rostrum, antennae, and eyes).

Subsequently, Lacordaire [2] placed this genus in the “Erirrhinides”. This opinion was followed by Kiesenwetter [3] when he described Hypoglyptus gracilis from Aetolia (currently Aetolia-Acarnaria, Greece). Heyden et al. [4] and Faust [5] placed Hypoglyptus in the Erirhinidae close to Aubeonymus Jacquelin du Val, 1855 and Pachytychius Jekel, 1861. A few years later, Faust [6] described the new species H. heydeni from Gaziantep (Turkey). Pic [7,8] was the first and only author who compared all species of this genus in a key to the species. On this occasion, he reported that Tychius elegans Brullé, 1832 and Hylobius graecus Pic, 1902–both described from Peloponnesus (formerly Morea)–actually belong to Hypoglyptus. In 1912, Leonhard [9], who evidently did not know the genus Hypoglyptus, described the new genus Acentroides for his new species A. conspersus from Macedonia (Greece), suggesting that this genus is related to Acentrus Desmarest, 1839 (currently in the Curculioninae, Acentrusini). In the same year, in his key to the European weevil genera, Reitter [10] placed Hypoglyptus in the tribe Erirhini (erratum for Erirhinini) of the subfamily Calandrinae (currently Curculioninae s. l. + Brachycerinae pars) near Dorytomus Germar, 1817, due to the presence of toothed femora. Winkler [11] and Klima [12] placed Hypoglyptus in Erirhininae, having synonymized Acentroides with this genus.

Subsequently, no author has dealt with Hypoglyptus, which was retained in Erirhinidae by Caldara [13], although doubtfully, since Kuschel [14] did not include it in this family where only genera with a pedo-tectal penis were included. It is noteworthy that Kuschel never mentioned Hypoglyptus, and therefore we cannot know for sure if he studied this genus. Finally, Oberprieler [15] agreed with Caldara’s opinion, suggesting that this genus does not belong to Erirhinini due to the dentate femora and therefore considered this genus as Curculionidae incertae sedis, as also reported by Alonso-Zarazaga et al. [16].

The aim of this study is to revise all species belonging to Hypoglyptus and to recommend the placement of this genus in the Curculionidae.

2. Materials and Methods

2.1. Samples

Despite our careful examination of the collections deposited in almost all European Museums and Institutes, as well as many private collections, only fewer than 50 specimens of Hypoglyptus were found for this study, which luckily includes type specimens of most taxa. Lectotypes were designated as appropriate, according to Article 74 of the International Code of Zoological Nomenclature [17], and other specimens of the type series, when available, were labeled as paralectotypes. All label data for each examined type specimen are reported verbatim; non-type specimens are ordered in a unified style.

2.2. Measurements

Measurements were made using an ocular micrometer in a Wild M8 stereoscopic microscope. Body length was measured from the anterior margin of the eyes to the apex of the elytra. The length of the rostrum (Rl) was measured in lateral view from the apex (excluding mandibles) to the anterior margin of the eye; its relative length was expressed as the ratio length of rostrum/length of pronotum (Rl/Pl). The length of the pronotum (Pl) was measured at the midline from the anterior margin to the base, whereas its width (Pw) was measured transversely at the widest point. The width of the pronotum was expressed as the ratio Pw/Pl. The length of the elytra (El) was measured at the midline from the transverse line joining the most anterior point of the humeri to the apex, whereas its width (Ew) was measured at the widest point. Proportions of the elytra were also expressed as the ratio El/Ew.

2.3. Description

Our redescription of the genus Hypoglyptus is more detailed than the original description. On the contrary, due to the high uniformity of the treated species, we briefly redescribe the five species by way of a “diagnostic redescription”, using only those characters the combination of which enables the identification of a particular species, ignoring the characters common to all species of the genus.

2.4. Terminology

We followed the online glossary of weevil characters proposed by C.H.C. Lyal [18].

2.5. Illustrations

Habitus photos were made with a high-resolution camera (Canon EOS 50D, Tokyo, Japan) connected to a macro zoom lens (Canon MP-E 65 mm). Male genital structures were dissected and treated for several days in 10% KOH. Male genitalia were photographed in glycerol with the same camera under a laboratory microscope (Intraco Micro LMI T PC, Tachlovice, Czech Republic). The multilayer pictures were processed using the software Combine ZP and Adobe Photoshop 9.0. Female genitalia were dissected from moisturized specimens; only spermatheca was embedded in Solakryl BMX (Medika, Praha), photographed under the same laboratory microscope as above, and its outline processed by the software Adobe Photoshop was illustrated. Sternite VIII (spiculum ventrale) was not illustrated since it showed almost no interspecific differences.

2.6. Acronyms

Institutional depositories are abbreviated according to The Insect and Spider Collections of the World Website [19]. Abbreviations of authors of host plants are reported only when mentioned for the first time as acronyms following the generally accepted list of botanist abbreviations by Wikipedia [20].

2.7. Depositories

The collection housing material studied in this revision is abbreviated as follows (in parentheses, the colleagues who provided loans to us):

GVPC	George Vandoros, private collection, Athens, Greece;
JRPC	Jacob Rüdiger private collection, Engen, Germany;
MKPC	Michael Košťál, private collection, Šoporňa, Slovakia;
MNHN	Muséum National d’Histoire Naturelle, Paris, France (H. Perrin);
MSNM	Museo civico di Storia Naturale, Milano, Italy (F. Rigato);
NHMB	Naturhistorisches Museum, Basel, Switzerland (C. Germann);
NHMW	Naturhistorisches Museum Wien, Wien, Austria (M. Jäch);
OLML	Oberösterreichisches Landesmuseum, Linz, Austria;
PJPC	Petr Jansa, private collection, Obříství, Czech Republic;
PSPC	Peter Sprick, private collection, Hannover, Germany;
RCPC	Roberto Caldara, private collection, Milano, Italy;
SBPC	Stanislav Benedikt, private collection, Plzeň, Czech Republic;
SMDEI	Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany (M. Schröter);
SNSB	Zoologische Staatssammlung, München, Germany (K. Neven);
ZMHB	Museum für Naturkunde der Humboldt-Universität, Berlin, Germany (J. Frisch).

2.8. Abbreviations in Descriptions

As = Asia; E = elytra (elytral); Eu = Europe; l = length; P = pronotum (pronotal); R = rostrum (rostral); w = width; ~ = approximately.

3. Results

3.1. Taxonomy

Curculionidae Latreille, 1802 s. l.

Curculioninae Latreille, 1802

Smicronychini Seidlitz, 1891

Hypoglyptus Gerstaecker

Hypoglyptus Gerstaecker, 1855: 172 (type species Hypoglyptus pictus Gerstaecker,1855) [1]. Lacordaire 1863, p. 482 [2]. Kiesenwetter, 1864: 272 [3]. Heyden et al., 1883: 165 [4]; 1891: 305 [21]; 1906: 658 [22]. Faust, 1886: 23 [5]. Pic, 1906a: 58 [7]; 1906b: 67 [8]. Reitter 1912: 75 [10]; 1916: 195 [23]. Winkler, 1932: 1538 [11]. Klima, 1934: 5 [12]. Alonso-Zarazaga & Lyal, 1999: 69 [24]. Caldara, 2011: 194 [13]. Oberprieler, 2014: 440 [15]. Alonso-Zarazaga et al., 2023: 566 [16].

Acentroides Leonhard, 1912: 341 (type species Acentroides conspersus Leonhard, 1912) [9]. Winkler, 1932: 1538 [11]. Klima, 1934: 5 [12]. Alonso-Zarazaga & Lyal, 1999: 69 [24].

Redescription. Male. Length 4.4–8.9 mm (rostrum excluded). Body: long, subelliptical, with dark brown to black integument. Rostrum: long (Rl/Rw 6.0–7.5), subcylindrical, almost of same width from base to apex; in lateral view weakly to moderately curved, in dorsal view with subparallel sides from base to apex; scrobes in lateral view oblique, visible till middle of rostrum, in dorsal view not visible, with rows of deep and dense punctures divided by narrow carinae. Antennae: inserted in apical third of rostrum; scape not reaching anterior margin of eye; funicle 7-segmented, as long as scape, first segment 3.0 × as long as wide, as stout as and 1.5 × longer than second segment which is 1.5 × as long as wide; segments 3–7 transverse, similar in shape and width; club oval, 0.30 × as long as funicle. Eyes: somewhat longer than wide, flat. Pronotum: subspherical to slightly transverse, more or less punctate-striate with interval between punctures distinctly rugulose, widest at or slightly behind middle, convex, covered with sparse, transversely directed brownish and white scales. Elytra: subelliptical to subrectangular (El/Ew 1.35–1.75), at base flat to concave, with sides rounded, subrounded to parallel, widest at about middle, convex or flat on disc, uniformly covered with brown scales and more or less apparent patches of pale scales at humeri, at middle in form of transverse band, and laterally at apex; interstriae flattened, smooth; striae usually clearly visible, with regular deep punctures. Legs: femora clavate, without or with teeth; tibiae more or less elongate, with sharp uncus, their outer margin in apical third more or less directed outward; tarsomere 1 1.5× longer than wide, tarsomere 2.0× as long as wide, tarsomere 3 bilobed and distinctly wider than tarsomere 2, onychium 1.5× longer than tarsomere 3; claws thin, equal in length, separated from base. Venter: prosternum with apical shallow emargination without rostral canal; procoxae contiguous; mesosternal process small, oval; metasternum moderately convex, with large, densely distributed punctures; ventrite 1 in its anterior part with very dense, large punctures, in its posterior part and ventrites 2–5 with more or less regularly distributed, mostly semisparse punctures. Ventrites 1 and 2 weakly concave, ventrite 5 with shallow impression. Male genitalia: penis compared to body size strikingly short, body of penis with parallel to moderately convergent sides, bluntly to sharply tapered at apex; temones 1.2–2.0× as long as body, tegmen with thin, long, well separated parameroid lobes being longer than tegmen diameter and reaching up to 1/2–3/4 of length of body of penis, manubrium of tegmen longer than tegmen diameter.

Female. Differing from male by dorsum of rostrum with less dense rows of punctures, intervals between rows flat. Ventrites 1 and 2 moderately convex, ventrite 5 without impression. Genitalia: spermatheca very different in shape among species, from normally structured with well-developed ramus and nodulus to simple with collum confluent with cornu.

Hypoglyptus elegans (Brullé) (Figure 1 and Figure 2)

Tychius elegans Brullé, 1832: 245 [25]. Pic, 1906a: 58 [7]; 1906b: 68 [8] (Hypoglyptus). Heyden et al., 1906: 658 [22] (Hypoglyptus). Winkler, 1932: 1538 [11] (Hypoglyptus). Klima, 1934: 6 [12] (Hypoglyptus).

Hypoglyptus pictus Gerstaecker, 1855: 173 [1]. Pic, 1906a: 58 [7]; 1906b: 68 [8]. Heyden et al., 1906: 658 [22]. Winkler, 1932: 1538 [11]. Klima, 1934: 6 [12]. n. syn.

Type locality. Peloponnesus (Greece).

Type material. Tychius elegans was described from an unknown number of specimens collected by François Louis Laporte in “Morea”, the ancient name of the Peloponnesus. No type specimen of this species was found in the collection Brullé housed at MNHN (H. Perrin, pers. comm.). However, a dozen specimens from “Morea” identified with this name in many historical collections and corresponding well to the original description (see below in material examined), and the drawing reported by Brullé [25] were considered.

Synonyms. Hypoglyptus pictus was described from an unspecified number of specimens collected in Corfu by Ludwig Parreyss, who labeled it as “Hylobius pictus i. litt.” (ZMHB). We found two topotypic specimens, respectively labeled: “Coll. Kraatz/Hypoglyptus pictus, Ins. ionic. Parr. [Parreyss]” (1, SMDEI) and “Wencker vid./Hypoglyptus pictus Gerst., Ins. Ioniae Parreyss original” (1, coll. von Heyden, SMDEI), completely corresponding to the original description.

Diagnostic redescription. Length 4.4–7.6 mm. Rostrum in lateral view regularly and moderately curved from base to apex. Pronotum subspherical, wider than long (Pw/Pl 1.13–1.16), with rounded sides, widest at middle, with moderately deep punctures mostly only poorly distinct since conjoined and forming short striae; covered with subrecumbent, mostly transversely oriented, strongly elongate (l/w 4–8), light brown and white scales. Elytra suboval, broad (El/Ew 1.36–1.41), with rounded sides, poorly prominent humeri, widest at middle (Ew/Pw 1.29–1.34), moderately convex, with oval, small, recumbent brown and much rarer, sparsely scattered white scales, humeri and subhumeral area very densely covered with oval (l/w 2–3), recumbent, imbricate white scales, in 2/3 of elytral length striking transverse bands reaching from interstria 3 to 8 and converging to apex, in preapical area irregular, relatively striking patches, both bands and patches formed by same type of scales as on humeri giving elytra bright contrasty pattern. Femora with small teeth. Body of penis from base to 2/3 almost parallel, then narrowed to apex, apex subrounded. Spermatheca with medium large corpus, relatively long cornu, and well-developed ramus.

Remarks. This species is easily distinguishable from other species of the genus by the broader, rounded, and convex elytra. Moreover, the punctures on the pronotum are almost indistinct, forming short, irregular striae.

Biological notes. This species was collected more frequently on flowers of Castanea but occasionally also on flowers of Fraxinus and twigs of Juniperus (G. Vandoros, pers. comm.). Unfortunately, in the complete absence of data on the biology of the immature stages, it is still impossible even to suppose the host plant.

Distribution. In all Greece, although rare (Peloponnesus, Thessaly, Epirus, Ionian Islands, West Greece). It seems, however, the most common species in this genus. Recently, this species was also collected in Albania. Therefore, it is probably more widely present in the Balkans.

Non-type material examined. Albania. Taronine, Gjirokaster, 18.5.2018, leg. Hengmith (1, PSPC). Greece. Peloponnesus: Taygetus, Krüper/Coll. Kraatz (1, SMDEI); Taygetos, Morea mer. (2, coll. Heyden, SMDEI; 1, coll. Kolze, SMDEI; 2, coll. Hoffmann, MNHN; 6, coll. Pic, MNHN; 3, coll. Solari, MSNM); Morea merid. Gaitzaes, Taygetos, 1902, Holtz (1, coll. Pic, MNHN); Lakonia, Mt. Taygetos, 750 m, Paleopanagia to Katafigio, 30.04.1999, leg. Wolf, det. Behne, coll. Wolf (1, OLML); Taygetus mountain, near Kryoneri village, alt. about 800 m., on flowers of Fraxinus, 36.968114, 22.390557. 14/V/2017, leg. Vandoros (1, GVPC); Taygetos mer. (4, NHMW, 5, MNHN, 1, RCPC, 4, SMDEI); Menalo Mts., Alonistaina env., N 37° 39’ E 22° 12’, 1200–1400 m, 1.-5.vi.2009, leg. T. Růžička (1 ♀, PJPC); Magouliana, 37°41’N/22°7′O, 1500 m, 22.5.1974, Balkan-Ägäis-Expedition, H. und U. Aspöck, H. und R. Rausch (1, coll. Dieckmann, SMDEI); Magouliana, N 37°41’ E 22°07’, 1500 m, 23.v.1974 (1 ♀ SMDEI); Piana/Tripolis 1.6.1985, K. Bernhauer (1 ♀, MKPC). Central Greece: Aetolia, mount Velouchi (1, coll. Pic, MNHN); Velouchi (1 ♀, MNHN). Thessaly: Tzoumerka mountain, near Neraida village, alt. about 1000 m, on Juniperus twigs, 39.443909, 21.229470. 12/V/2018, leg. Vandoros (4, GVPC); Pindos, Karpenisi, coll. Apfelbeck (2, MSNM). Epirus: Platanusa, Xerovuni, 700–800 m, 12-VI-33. Beier (2, MSNM); Mihlas Monastery (Thesprotia), alt. about 600 m., on flowers of Castanea, 39.612649, 20.485890, 26/VI/2009, leg. Vandoros (1, GVPC). Ionian Islands: Corfu, 2 km w Spartilas, 350 m, from Hedera, 4.6.2014, leg. Rüdiger” (1, JRPC); Corfu, Pantocratoras mountain, about 800 m, on flowers of Castanea, 39.765791, 19.887175. 01/VII/2009, leg. Vandoros (1, GVPC); Corfu, coll. Kraatz (2, SMDEI).

Hypoglyptus heydeni Faust (Figure 3 and Figure 4)

Hypoglyptus heydeni Faust, 1889: 236 [6]. Pic, 1906a: 58 [7]; 1906b: 68 [8]. Heyden et al., 1906: 658 [22]. Winkler, 1932: 1538 [11]. Klima, 1934: 6 [12].

Type locality. Gaziantep (Turkey).

Type series. This taxon was described based on specimens collected in Aintab (erroneously “Antiab” in the original description, currently Gaziantep) by Lucas Friedrich Julius Dominikus von Heyden. At SMDEI, we examined two specimens considered as syntypes labelled: “609./Aintab [=Gaziantep], Asia min., Staudgr./Faust vid./Pic vid./Hypoglyptus Heydeni Fst., Aintab, Staudgr. original/Syntypus” and “[Small light yellow rounded card]/Heydeni Fst., Cauc., Staudg. [Staudinger]/993./Hypoglyptus Heydeni Fst., Aintab, Staudgr. Original/Pic vid./Syntypus”. We decided to designate the former specimen, 6.72 mm long, almost completely preserved male with missing right protarsus and left protarsal onychium, as the lectotype of Hypoglyptus heydeni Faust by adding a printed red label “LECTOTYPUS Hypoglyptus heydeni Faust R.Caldara et M.Košťál des. 2024”. The latter, a completely preserved female specimen, was labeled as paralectotype accordingly.

Diagnostic redescription. Length 6.7–8.8 mm. Rostrum in lateral view distinctly curved at base, then regularly and moderately curved to apex. Pronotum as long as wide (Pw/Pl 0.97–1.01), with weakly rounded sides, widest at middle, with moderately deep punctures mostly poorly distinct due to intervals between punctures being convex only at their sides, forming irregular confused striae, with similar vestiture as in H. elegans, but scales less apparent. Elytra long (El/Ew 1.70–1.74), narrow, subrectangular and with rectilinear parallel sides in anterior two thirds (Ew/Pw 1.39–1.43), with poorly prominent humeri, flat on disc, with similar vestiture as in H. elegans, but with slightly less striking pattern, bands and patches of creamy hue. Femora with no or very small teeth. Body of penis as in H. elegans but shorter. Spermatheca with robust corpus, long cornu and ramus, and well developed nodulus.

Remarks. Among the species with elongate and flattened elytra, this species is easily distinguishable by the indistinct or completely lacking femoral teeth. It shares the shape of the pronotum (with slightly rounded sides) and the almost indistinct humeri with H. gracilis. These two characters allow both species to be separated from H. conspersus.

Distribution. Greece (Samos island), Turkey, Syria.

Non-type material examined. Greece. Samos Isl., Oros Ambelos W-Mytilini/N37°46’06”- E26°51’23”, 520 Felswand/Moos. Polsterpflanzen, 1.4.2010, leg. Germann (1, NHMB). Turkey. Gezbeli, Tahtali Daglari, Kayseri env., 28.5.2001, leg. J. Mertlik (1, PJPC). Syria. Env. d’Alep, Syrie, Bonnaire (1, coll. Hoffmann, MNHN).

Hypoglyptus gracilis Kiesenwetter (Figure 5 and Figure 6)

Hypoglyptus gracilis Kiesenwetter, 1864: 274 [3]. Pic, 1906a: 58 [7]; 1906b: 68 [8]. Heyden et al., 1906: 658 [22]. Winkler, 1932: 1538 [11]. Klima, 1934: 6 [12].

Type locality. Aetolia (West Greece).

Type series. This taxon was described from a unique male specimen collected in Aetolia (currently the regional unit of Aetolia-Acarnania, West Greece) without a more detailed locality by Kiesenwetter. This specimen was not found at the SNSB, where the Kiesenwetter collection is deposited (K. Neven pers. com.).

Diagnostic redescription. Length 7.5–8.7 mm. Rostrum in lateral view distinctly curved at base, then regularly and moderately curved to apex. Pronotum as long as wide (Pw/Pl 0.96–1.00), with moderately rounded sides, widest behind middle with moderately deep, partly separated, partly confluent punctures forming sinuate short striae. Elytra long (El/Ew 1.72–1.75), narrow, subrectangular and in anterior two thirds with rectilinear parallel sides (Ew/Pw 1.39–1.43), with poorly prominent humeri, flat on disc. Pale patches formed by oval creamy scales in humeral area relatively small, reaching from base of elytra to less than one-tenth of elytral length, transverse band behind midlength less striking due to scattered oval pale scales covering entire elytra, preapical patches small. Femora with very robust teeth. Body of penis with very slightly convex sides, at apical third narrowed to apex, apex in dorsal view relatively sharply ended, body in lateral view slightly arcuate. Spermatheca simple, with robust corpus and long thin cornu.

Remarks. Due to the large femoral teeth, this species seems to be more closely related to H. graecus than to the other species. However, in this last species, the elytra are suboval (vs. parallel-sided) and with almost less distinct elytral pattern due to the presence of oval pale scales across the entire elytral surface.

Distribution. Greece (Central Greece, Peloponnesus).

Non-type material examined. Greece: Central Greece: Ȯri Vardoússia mts., Dáfnos env., 1600–2100 m, 26.V.1997, leg. Benedikt (2 ♂♂, SBPC); Peloponnesus: Taygetus, Krüper/Tayget. Dr. Krüper/Coll. Kraatz/Hypoglyptus gracilis Ksw. (1, SMDEI); Menalo Mts., Alonistaina env., N 37° 39’ E 22° 12’, 1200–1400 m, 1.-5.vi.2009, leg. T. Růžička (1 ♂, PJPC). Epirus: Platanusa, Xerovuni, 700–800 m, 2.-12-6.1933, leg. Beier (1 ♂, MSNM). Ionian Islands: Lefkada, Eglouvi, 700 m, 14.5.2005, leg. F. Angelini (1 ♀, PJPC).

Hypoglyptus graecus (Pic) (Figure 7c,d and Figure 8d)

Hylobius graecus Pic, 1902: 67 [26]; 1906a: 58 [7]; 1906b: 68 [8] (Hypoglyptus). Heyden et al., 1906: 658 [22] (Hypoglyptus). Winkler, 1932: 1538 [11] (Hypoglyptus). Klima, 1934: 6 [12] (Hypoglyptus).

Type locality. Taygetus mountains (Peloponnesus, Greece).

Type series. Hylobius graecus was described based on one specimen from Taygetos. In coll. Pic (MNHN), we examined this specimen labeled “Grèce: Taygetos/type/Hyl. graecus Pic/prés gracilis Ksw/Museum Paris Coll. M. Pic”. We dissected this well-preserved, 6.41 mm long female specimen, with a missing left mesotarsus, for the spermatheca and compared it with the only other female of this species we had for the study. For clarity, we added a printed red label: “HOLOTYPUS Hylobius graecus Pic R.Caldara et M.Košťál vid. 2024”. Only a few years later, Pic (1906) transferred the species to Hypoglyptus.

Diagnostic redescription. Length 6.4–7.2 mm. Rostrum in lateral view distinctly curved at base then weakly curved to apex. Pronotum as long as to slightly wider than long (Pw/Pl 1.00–1.08), in basal half almost rectilinearly widened anteriad, then regularly rounded to anterior margin, widest shortly behind 0.6 of its length, with confluent deep punctures partly separated by shiny ribs. Elytra suboval (El/Ew 1.67–1.69), with subrounded to subparallel, not rectilinear sides (Ew/Pw 1.38–1.40), with rounded, weakly prominent humeri, flat on disc. Humeral patches formed by oval creamy scales small but distinct, transverse band medium thick, strikingly contrasting with almost bare areas in front and behind it, preapical patches relatively small but distinct. Femora with robust teeth, pro- and mesofemora with indentation at distal tooth apposition. Spermatheca simple, with moderately robust corpus and robust cornu. Male unknown.

Remarks. This species is characterized by large femoral teeth. It seems to be most closely related to H. gracilis but can be easily distinguished from this species by subparallel to subrounded, never rectilinear, elytral sides in dorsal view. Moreover, it differs from H. gracilis in the elytral area between humeral spots and the transverse band being almost free of oval pale scales, which strongly contrasts with the transverse bands formed by crowded oval pale scales.

Distribution. Greece (Peloponnesus).

Non-type material examined. Greece: Peloponnesus: Taygetus, leg. Krüper (1 ♀, SMDEI).

Hypoglyptus conspersus (Leonhard) (Figure 7a,b and Figure 8a–c)

Acentroides conspersus Leonhard, 1912: 341 [9]. Klima, 1934: 6 [12] (Hypoglyptus).

Type locality. Athos peninsula (Macedonia, Greece).

Type series. This species was described from a single male specimen collected at the Athos peninsula (Macedonia, Greece) by Artur Schatzmayr. It is preserved in coll. Leonhard, currently deposited in SMDEI. We examined this male specimen labeled: “Macedonia, Athos, Schatzmayr, Coll. O. Leonhard/Acentroides n.g. conspersus n.sp. Leonh. Type/Holotypus/Hypoglyptus heydeni Fst. det. Zumpt 1931” and two other topotypic male specimens (see below in material examined).

Diagnostic redescription. Length 6.5–7.6 mm. Rostrum in lateral view weakly curved from base to apex. Pronotum with rounded sides, more or less isodiametric (Pw/Pl 0.99–1.02), with very deep punctures well separated by distinctly convex rugose intervals, covered with scales similar to those in H. elegans, but less apparent and without whitish scales. Elytra narrow (El/Ew 1.67–1.70), with rectilinear parallel sides in anterior two-thirds (Ew/Pw 1.33–1.36), with moderately angulate humeri, flat on disc, with less apparent patches and bands as in H. elegans, making elytral pattern much less striking.

Femora with small teeth. Body of penis with slightly convex sides, at end of apex in dorsal view somewhat tapered, apex more obtuse than in other species of the genus. Female unknown.

Remarks. Among the species with elongate elytra, H. gracilis and H. heydeni, this species seems to be intermediate in the size of femoral teeth. Moreover, it differs from both species in the more rounded pronotum, with very deep and well-separated punctures.

Distribution. It is currently known only from the type locality in northern Greece.

Non-type material examined. Greece: Athos (Macedonien), Schatzmayr (2 ♂♂, MSNM).

3.2. Key to the Species

• Pronotum with deep and large punctures separated by convex, thin, shiny interspaces, its shape in dorsal view with almost regularly rounded sides, more or less isodiametric (Figure 7a).……..……………………….………...... H. conspersus (Leonhard)

-

Pronotum with moderately deep, very densely distributed to confluent punctures often forming longitudinal ribs, its shape in dorsal view almost rounded to subconically narrowed posteriad........................................................................................ 2

2.

Profemora without teeth or with small teeth never longer than 0.2 of profemur width at tooth apposition (Figure 1 and Figure 3)............................................................................... 3

-

Profemora with large teeth always longer than 0.5 of profemur width at tooth apposition (Figure 5c and Figure 7a,b)........................................................................................ 4

3.

Profemora with small teeth. Elytra shortly oval, broad, in dorsal view in basal two thirds clearly rounded (Figure 1).................................................................. H. elegans (Brullé)

-

Profemora without teeth, at most with indicated tubercles. Elytra oblong, narrow, in basal two thirds subparallel to slightly rounded behind humeri (Figure 3)………………………………………………………………………... H. heydenii Faust

4.

Elytra in dorsal view subparallel, area between posthumeral spots and transverse band formed by crowded oval pale scales covered with semidensely distributed scales of same type resulting in indistinct elytral pattern. Anterior part of pronotum with small but distinct longitudinal shiny area, pronotum widest at midlength (Figure 5). Body size larger (~7.7 mm)......................................... H. gracilis Kiesenwetter

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Elytra in dorsal view suboval, area between posthumeral spots and transverse band formed by crowded oval pale scales almost bare, with small recumbent brownish scales and only few oval pale scales resulting in striking elytral pattern. Anterior part of pronotum at most with thin longitudinal rib, pronotum widest behind midlength (Figure 7c,d). Body size smaller (~6.5 mm)…. H. graecus (Pic)

4. Discussion

At present, the genus Hypoglyptus appears to comprise five very similar species, which are distinguishable by few but clear characters. The more peculiar characters are only in the shape of the pronotum and elytra, the pronotal sculpture, and the more or less distinct teeth of the femora. No valuable differences between the species of the genus were found in the shape of the head (rostrum, including its sculpture, scrobes, antennae, and eyes), dorsal vestiture, ventral characters, tibiae, and tarsi. Male genitalia are also relatively uniform, the apex of the penis in dorsal view more or less moderately sharply tapered, obtusely ended, not tipped. On the other hand, the shape of the spermatheca seems to differ substantially among species (Figure 2d, Figure 4d, Figure 6d and Figure 8d). However, it is worth noting that we illustrated but did not use these differences in the comparative notes of the species before considering possible variation because our data on the spermatheca are currently based only on one or two specimens for each species.

The first step of our study was to understand if this genus did indeed belong to the Erirhininae, as previously supposed, or not, as more recently suggested. We examined and illustrated the male genitalia of Hypoglyptus for the first time and finally could reject its belonging to Erirhininae on account of their pedal-type penis. In fact, it is well known that in the Erirhininae the penis is almost always of the pedotectal type [15].

A further step has been to identify a subfamily and a tribe in which to place this incertae sedis genus. Based on a morphological comparison with other genera and considering morphological characters of the five species belonging to the genus Hypoglyptus, we believe the shape of the rostra with characteristic deep lateral striae and characteristics of the tibiae and the genitalia are fundamental. On this basis we think that this genus really seems very closely related to Pachytychius and Aubeonymus as already supposed [4,5,22], both genera recently included in the tribe Smicronychini of the subfamily Curculioninae [27]. The most striking difference between these two genera and Hypoglyptus seems limited to the pattern of the elytral vestiture, which is curiously very similar to that in Hylobius and Pissodes Germar, 1817, belonging to Molytinae, as shown by the fact that a species of Hypoglyptus, H. graecus, was described as Hylobius [26]. In conclusion, based on these arguments, we herein propose the placement of Hypoglyptus in Curculioninae Smicronychini. However, we want to emphasize that our current proposal is only provisional because it is not based on established synapomorphies. In fact, as far as the phylogeny of the tribes of Curculioninae is concerned, the intrageneric relationships of species as well as the placement of the genera in this tribe have not been fully considered. The subfamily Curculioninae is a morphologically and biologically highly diverse group of weevils, without any clear agreement yet of it representing a monophyletic taxon in its widest sense, either morphologically [28,29,30] or also on the basis of preliminary molecular analyses [31,32], which so far have not shown clear monophyly of and between tribes of Curculioninae. As a result, the classification of the subfamily and its tribes remains tentative and may change significantly in the future.

Apart from the similarity in habitus of the two above-mentioned genera of Hylobinae, the distance between Hypoglyptus and this subfamily is high. The more distinctive morphological characters are in the shape of the rostrum and of the tibial apices. It is, however, noteworthy that the biology of Hypoglyptus species, in particular the host plants, might be more similar to that of Hylobius and Pissodes than to that of Pachytychius and Aubeonymus. Data on the host plants of Hypoglyptus, although very scant, seem to focus in the same direction, i.e., the likelihood that they are living on the same tree species as Hylobius and Pissodes. One might venture to suggest the possibility of convergent evolution of vestiture due to their evolution in very similar habitats and the same host plants, even though they belong to different families, i.e., Fagaceae vs. Pinaceae), whereas the few species of Pachytychius and Aubeonymus with known biology are associated with shrubs and herbaceous plants belonging to Fabaceae and Poaceae.

Unfortunately, until now we had no opportunity to examine material suitable for a molecular study, which might give further substantial evidence for the correct placement of Hypoglyptus in the vast and greatly multiform family of Curculionidae.

Finally, it should be emphasized that the restricted distribution of the genus Hypoglyptus seems to be limited to four species in the Balkans (mainly Greece) and a fifth species in an eastern Greek island (Samos), Turkey, and Syria. It is likely that the distribution of the genus is wider in the Balkans and in the Middle East. We hope that our revision of this poorly known genus could encourage more detailed research.

5. Catalogue

Hypoglyptus elegans (Brullé, 1832): 245 (Tychius) Eu: Albania; Greece

= Hypoglyptus pictus Gerstaecker, 1855: 173

Hypoglyptus gracilis Kiesenwetter, 1864: 274 Eu: Greece

Hypoglyptus graecus (Pic, 1902): 67 (Hylobius) Eu: Greece

Hypoglyptus heydeni Faust, 1889: 236 Eu: Greece (Samos) As: Syria; Turkey

Hypoglyptus conspersus (Leonhard, 1912): 341 (Acentroides) Eu: Greece