A review of Conocetus Desbrochers des Loges, 1875, subgenus of Polydrusus Germar, 1817 (Coleoptera, Curculionidae, Entiminae)

The species of the subgenus Conocetus Desbrochers des Loges, 1875 are reviewed and Polydrusus (Conocetus) transjordanus sp. nov. is described. Upon examination of the holotype of Polydrusus bardus Gyllenhal, 1834, it was observed that the species hitherto determined sensu auctorum as P. bardus was a misidentification. The specimen in question was therefore unnamed and is thus newly described as Polydrusus (Conocetus) crinipes sp. nov. Polydrusus femoratus (Stierlin, 1888) is a junior synonym of P. angustus (Lucas, 1854). Polydrusus gracilicornis Kiesenwetter, 1864, P. cylindrithorax (Desbrochers des Loges, 1900) and P. quadraticollis (Desbrochers des Loges, 1902) are proposed as junior synonyms of P. bardus. Polydrusus zurcheri (Schilsky, 1912) is proposed as a junior synonym of P. grandiceps (Desbrochers des Loges, 1875). Polydrusus kahri Kirsch, 1865 is transferred from subgenus Conocetus to Denticonocetus subgen. nov., with P. siculus Desbrochers des Loges, 1872 and P. vodozi Desbrochers des Loges, 1903 both recognized as new junior synonyms of P. kahri. The lectotypes of P. gracilicornis, P. zurcheri, P. marcidus Kiesenwetter, 1864, P. gracilis (Stierlin, 1888), P. rhodiacus (Schilsky, 1912) and P. grandiceps are designated. A key, figures, label data and distribution maps are provided for all species, except for P. longus (Stierlin, 1884), for which no specimens were available for examination, and whose placement in the subgenus Conocetus remains uncertain (thus categorized as incertae sedis). Polydrusus angustus is recorded for the first time for Italy, P. rhodiacus for mainland Turkey and P. festae (Solari, 1925) for Greece.

The subgenus Conocetus is characterized as follows: 1) rostrum broad, transverse; 2) antennal scrobes lateral, short and triangular with lower margin protruding downwards and obtusely angled; 3) left mandible stronger, rectangularly protruding; 4) temples always well visible; 5) eyes oval to long-oval, more or less bulged, protruding from the head's outline; 6) antennae very slender and thin; 7) pronotum mostly as long as wide; 8) legs slender, femora without teeth; 9) integument of elytra and pronotum with circular to oval adjacent scales and bare areas where hairs arise.After the present review, Conocetus and Denticonocetus subgen.nov.consist of 12 species, all distributed in the Eastern Mediterranean region, except for P. longus (Stierlin, 1884) from Morocco -reported here as incertae sedis.Collection localities are cited directly from labels with original spelling and punctuation.For type specimens, the different specimen labels are given from the top downward and separated by a double slash (//).Additional information and general remarks are highlighted using square brackets [ ].

Abbreviations
Photographs were taken with a 5-megapixel digital camera (Leica DFC 420).Series of images were captured through a binocular microscope (Leica MZ16) and processed with Auto-Montage software (Imagic Image Access, Version 8).All measurements were taken digitally with the measurement-tool of the above mentioned Auto-Montage software.Body length was measured from the anterior margin of sclerite, see Fig. 9D-P, whereas in Eustolus the internal sac consists of several differently shaped, complex sclerites, and in the rather heterogeneous Polydrusus s. str. the internal sacs consist of prevailing tissues with rasp-like teeth.

Etymology
The subgeneric name Denticonocetus subgen.nov. is of male gender and combines the characteristically dentate femora (in Latin: dentis = tooth) and the morphologically most similar subgenus Conocetus.

Comments on new synonymies
Based on all specimens examined and their identical internal sacs (see Fig. 9A-C), P. siculus and P. vodozi are hereby regarded as junior synonyms of P. kahri.Magnano (1964) resurrected P. siculus from synonymy, mainly based on the differences given by Desbrochers des Loges (1872) in the original description.However, upon examination of specimens from various localities for the present study, these characters do not support a species status, therefore Polydrusus siculus = Polydrusus kahri.
In the case of P. vodozi, the synonymy with P. kahri proposed by Hoffmann (1950) and Schott (2014) is formally approved here (Polydrusus vodozi = Polydrusus kahri).The type specimen in the collection of Desbrochers was examined by L. Schott and confirmed as conspecific with P. kahri; furthermore, a male specimen from Corsica was examined (see below).

Remarks
Polydrusus kahri is a widespread species reported from France (Alpes Maritimes), including Corsica (Vizzavona: Hoffmann 1950; Schott 2014), Austria to Dalmatia, Bosnia-Herzegovina, Macedonia, Montenegro (Yunakov 2013; no specimens presently examined and not included in Fig. 10), Greece, and all of Italy including Sicily, but apparently excluding Sardinia (mentioned by Hoffmann 1950 CoLour.Body colour reddish-brown.Head, pronotum and elytra set with oval to roundish, vivid green shimmering scales and long, pointed, light brownish adjacent hairs.head.Rostrum short and wide, almost twice as wide as long.Eyes oval, irregularly bulged, strongest in first third, well protruding from outline of head.Pterygia well developed, visible from above.Pterygial span as wide as frons just behind the eyes.Rostral dorsum and frons between the eyes flat, upper side of head behind eyes slightly bulged.Rostral dorsum irregularly striato-punctuate with carinula in the middle.Epistome well visible, V-shaped, margin glossy.Mandibles strong, left mandible above right one, thus fore margin of epistome assymmetrically protruding leftwards.Antennal scrobes lateral, short and triangular, lower margin buckled downwards, with obtuse angle.Temples visible, ½ the maximal eye length.
antennae.Long and slender, antennal funiculus longer than scape, reddish-brown, scape bowed, clubbed towards apex, reaching backwards into first third of pronotum.Antennal funiculus with 7 antennomeres: 1 st longer than 2 nd and 3 rd ; 5 th to 7 th of same length; 4 th slightly longer than 3 rd and 5 th to 7 th ; club with 3 segments, elongate-oval.
Pronotum.Transverse (L/W: 0.7-0.8),sides slightly rounded, widest just behind the middle, constricted just before fore margin and simply rounded towards hind margin.Hairs and oval to lanceolate greenish scales directing towards an imaginary line in the middle of the disc.Scales at disc of pronotum narrower oval.
eLytra.L/W: males 2.0, females 1.8-1.9.Elongate, widest at shoulders and almost parallel (males) or widest behind the middle (females), round-pointed towards apex, shoulders present, with hind wings.Striae with shorter, adjacent white hairs.Interspaces with long, light brownish, adjacent, pointed hairs standing irregularly.Vestiture consisting of regular-standing broad oval to roundish scales with vivid green shimmer.Scales narrower along suture.
Legs.Strong, reddish-brown coloured to yellowish, all femora edentate, set with whitish hairs with a pearl-like lustre.Tarsi with first tarsomere twice as long as second, third bilobed, about 1.5 times as wide as the second, fourth one minute, claw segment as long as second and third together, claws fused at base.maLe genitaLia.Penis with apophyses shorter than median lobe, this attenuated towards broad triangular apex with blunt tip, in lateral view flattened (Fig. 7E).Internal sac wrench-like, with leaf-like flattened base, two triangular sclerites at apex and a thin, tube-like, bowed sclerite in-between in lateral view (Fig. 9G).
FemaLe genitaLia.Spiculum ventrale with very long and slender apodeme, plate hardly sclerotized.Spermatheca C-shaped with short nodulus and ramus; nodulus twice as long as ramus.

Remarks, variability and differentiation
The new species corresponds to specimens misidentified by authors as Polydrusus bardus.Examination of the holotype of P. bardus revealed that the description by Gyllenhal (in Schoenherr et al. 1834) referred instead to a species commonly known as P. gracilicornis Kiesenwetter, 1864 (or its junior synonyms, see the overview above for details), and therefore has priority over that name.
The reddish-brown to yellowish legs, with hairs but deprived of scales, are characteristic for both P. crinipes sp.nov.and P. rhodiacus.Polydrusus crinipes sp.nov.further differs from P. rhodiacus by the protruding convex eyes (Fig. 3A-B) (vs elongate drop-shaped in P. rhodiacus; Fig. 2E-F).

Ecology
The new species was collected from May to July, often along rivers (e.g., Nestos River), from sea level to montane altitudes, on various deciduous trees (e.g., Corylus avellana, Populus, Ulmus, Ziziphus).

Etymology
The name of the new species, transjordanus, is derived from its distribution across the Jordan River.head.Rostrum short and almost twice as wide as long.Eyes oval, regularly and moderately bulged, protruding from outline of head.Pterygia well developed, visible from above.Pterygial span as wide as frons just behind the eyes.Rostral dorsum and frons between the eyes flat, upper side of head behind eyes slightly bulged.Rostral dorsum irregularly striato-punctuate with carinula in the middle.Epistome well visible, V-shaped, margin glossy.Mandibles strong, left mandible above right one, thus fore margin of epistome asymmetrically protruding to the left.Antennal scrobes lateral, short and triangular, lower margin buckled downwards, obtuse angled.Temples visible, ⅔ of the maximal eye length.

Holotype
antennae.Long and slender, yellowish, scape bowed, clubbed towards apex, just reaching backwards (laterally) to fore margin of pronotum.Antennal funiculus with 7 antennomeres: 1 st longer than 2 nd ; 3 rd to 7 th of same length but slightly broadening; club with 3 visible segments, elongate-oval.
Pronotum.Simply rounded towards hind margin.Hairs and oval to lanceolate greenish scales directing towards imaginary point in middle of fore margin.Scales at margins of pronotum mostly standing more densely.
eLytra.L/W: 1.7-1.8.Elongate, widest at shoulders and parallel (males) or widest behind middle (females), round-pointed towards apex, shoulders present, with hind wings.Striae with short, adjacent white hairs as long as puncture diameter.Interspaces with long, whitish, semi-raised and pointed hairs standing regularly in one row.Vestiture appearing spotty and consisting of oval to elongate-oval scales with greenish pearl-like lustre.Scales narrower and smaller along suture.
Legs.Strong, reddish-brown to yellowish coloured, all femora edentate, set with whitish hairs and oval scales with a greenish pearl-like lustre.Tarsi with first tarsomere twice as long as second, third bilobed, about 1.5 times as wide as second, fourth one minute, claw segment as long as second and third together, claws fused at base.maLe genitaLia.Penis with apophyses shorter than median lobe, this attenuated up to ⅔ of its length, from there broadening towards triangular apex with prolonged blunt tip protruding tongue-like, flattened in lateral view (Fig. 6E-H).Internal sac wrench-like, with leaf-like flattened base, two S-shaped sclerites at apex and a strong, b-shaped sclerite in-between in lateral view (Fig. 9O).
FemaLe genitaLia.Spiculum ventrale with very long and slender apodeme, plate hardly sclerotized.Spermatheca C-shaped with short nodulus and slightly longer, strongly bowed ramus.

Variability and differentiation
The density of the vestiture varies and the colour of the scales varies from greenish to whitish, but always with a pearl-like lustre.The size also varies considerably: males are generally smaller than females, but the eyes of males are bigger, in relation to head size, than those of females.Polydrusus (Conocetus) transjordanus sp.nov. is morphologically most similar to P. grandiceps, differing in the smaller eyes (in relation to head size; Fig. 5A-B), mostly more greenish and more oval scales, and the more gracile penis (see key; Fig. 6E-H).Polydrusus bardus is at first sight morphologically similar to P. transjordanus sp.nov.and may reach the distribution area of the latter at the north-western border (ancient records from "Syria"; see under bardus).However, the vestiture of P. bardus consists of denser and more regular standing, roundish and more vivid-green scales on the elytra and pronotum (loosely standing, oval and pale greenish ones in P. transjordanus sp.nov.), and shorter, more adjacent hairs on the head, pronotum and elytra (about twice as long and more steeply raised in P. transjordanus sp.nov.).

Ecology
The new species was found almost year-round (from January to November) and collected mainly in woodland on both evergreen and summer-green oaks (e.g., Quercus ilex, Q. boissieri, Q. calliprinos, Q. ithaburensis) and on Pistacia palaestina, from lowlands up to montane altitudes.

Variability and differentiation
Males are more gracile than females.The colour of legs varies from dark brown and blackish to yellowish.The most similar species is Polydrusus calabricus which shares the body shape (long-oval elytra) and the shape of the penis (Fig. 7F-G).Both are easily separable by the shape of the eyes (see key and Fig. 3C-F).Only P. rhodiacus shows similar eyes (Fig. 2E-F), but differs in legs deprived of scales and the elongate shape of the penis (Fig. 7D).

Ecology
Collected from April to June (exceptionally also in September) at various altitudes from beach to montane level from different deciduous trees (Amygdalus, Pistacia lentiscus, Prunus, Quercus) and Cupressaceae.

Type locality
The type locality of P. bardus is Thracian Chersonese, today Gallipoli in Turkish Thrace.

Remarks
As already stated by Schilsky (1910), P. (Conocetus) bardus was often confused and misinterpreted (see under P. crinipes sp.nov.), and it was only by examining the type specimen that the true identity of the species could be clearly established.Desbrochers des Loges (1902) confused it with P. marcidus in his redescription, but there are also examples in the revised collections where P. bardus (or P. crinipes sp.nov.) were confused with P. calabricus (e.g., det.Stöcklein NMB).

Variability
This often misinterpreted species varies considerably in size, vestiture (scale size, colour), vestiture of legs (metallic hairs with or without scales intermixed), length and orientation of hairs on elytra and, to a lesser degree, in the shape of the pronotum, which is mirrored in the different names aiming for the shape of the pronotum (cylindrithorax, quadraticollis).However, careful examination of the shape of the penis as well as the internal sac across a comprehensive body of material (see above) allowed the identification of a single, more widely distributed species.

Ecology
Desbrochers des Loges (1902) indicated "sur les Pins" [on pine trees] in his description.On Crete Polydrusus bardus was beaten from Quercus ithaburensis (C.Germann, pers.obs.) and Q. pubescens (Thompson, data taken from labels).Furthermore, according to label data from various collectors, the species was also collected from Castanea sativa in Turkey (e.g., N. Lodos), and from Quercus ilex, Q. coccifera and Q. ithaburensis macrolepis in Greece (L.Friedman).Records are from April to August, from sea level to subalpine altitudes.(Faust,

Type locality
Cyprus.

Variability
Rather constant in size and vestiture, the colour of the scales varies from greenish to brownish.

Ecology
Collected from various trees (L.Behne; Pistacia, Pinus, Juniperus, Cistus) in creek valleys and Olive groves at various altitudes in spring and summer (from April to August).

Variability and similar species
The diagnosis given by Faust (1890) is precise: "...sie kann sehr leicht mit angustus Luc.verwechselt werden, wenn man die breitere Stirn, die kürzeren, mehr gewölbten Augen, den breiten Rüssel und die dünneren Beine von calabricus nicht beachtet."[…it (P.calabricus) can very easily be confused with angustus, if the wider frons, the shorter and more convex eyes, the wider rostrum and the more slender legs of calabricus were not considered].See also the comments above under P. angustus, the most similar species to P. calabricus.

Ecology
Collected from May to June, from sea level to subalpine altitudes.

Remarks
Solari (1925) provided the following (type) localities (included in Fig. 12): Derna, Zavia (= Az Zawiyah), Mechili, Tecnis (= Taknis) and Tolmetta.The first records of P. festae outside of Libya were already reported by Germann et al. (2015) as specimens of an unknown Conocetus sp. from Samos Island.It is remarkable that this brachypterous and thus supposedly little-mobile species occurs across the Mediterranean Sea.This can be explained by the recent introduction of this species in Greece (Samos Island and Crete), although the first specimens known from Crete (without collecting date, see above) were collected by Gustav Paganetti-Hummler (1871-1949), hence a very recent introduction can be excluded.Polydrusus festae is therefore recorded here for the first time from Greece.

Variability and similar species
The species was compared with both P. baudii and P. marcidus by Solari (1925), based on the key by Schilsky (1910).The squamulate scutellum, the head shape, pronotum and the oval elytra (Fig. 1C-D) as well as its brachyptery are very characteristic and not shared with other species of the subgenus.
ISRAEL: 1 ex., Qiryat Tiv'on, on Quercus ithaburensis, 25 Apr. 1954 Kraatz]."However, the chosen lectotype and paralectotype, which were the only specimens pinned under the species' name in the collection of Ernst August Hellmuth von Kiesenwetter (in ZSM), fit perfectly the author's description and it is very likely that the author based his description on them.Kiesenwetter probably bought them from Theobald Krüper, who was known to sell insects from Greece from 1859 (Horn et al. 1990), then labelled them himself.
Four syntypes of Polydrusus gracilis (Stierlin, 1888) where the lectotype and three paralectotypes are selected in accordance with the description by Stierlin (1888b):

Remarks
Unfortunately no specimen of this seemingly very characteristic species, based on its narrow and very elongate elytra (length: 5 mm, width: 1 mm), which are 3 times as long as wide (Stierlin 1884), could be examined in the present review.Stierlin (1884) compared P. longus with P. bardus (whereas with present knowledge, P. crinipes sp.nov.was meant).However, the distribution of P. longus, which seems to be restricted to the westernmost part of the Mediterranean basin, in comparison with the eastern focus of all other species of the subgenus, is at least surprising.One specimen from the BMNH was determined by L. Magnano as "Polydrusus (Conocetus) longus Stl.", but belongs instead to Polydrusus (Chomatocryptus) xanthopus Gyllenhal, 1834.As the placement in Conocetus cannot be verified, and is doubtful based on the deviant distribution and the very elongate habitus, the species is preliminarily treated as incertae sedis.
, but not included in Colonnelli 2003, nor in Abbazzi & Maggini 2009).Records by Yunakov (2013) from Cyprus are highly dubious and may refer to misidentifications.Polydrusus kahri shows large variability in size and density of vestiture.

bardus = P. cylindrithorax Desbrochers des Loges, 1900 syn. nov.
The description of P. cylindrithorax was based on specimens from Rhodes.All examined specimens from Rhodes belong to P. bardus.