Nematocerus barbitibia, Colonnelli, 2014

Colonnelli, Enzo, 2014, Apionidae, Nanophyidae, Brachyceridae and Curculionidae except Scolytinae (Coleoptera) from Socotra Island, Acta Entomologica Musei Nationalis Pragae 54, pp. 295-422 : 354-356

Nematocerus barbitibia sp. nov.

( Figs 60, 61 ) Type material. HOLOTYPE: J ( NMPC), ‘ Yemen, Socotra Isl., Wadi Faar , // GPS 12.433N, 54.195E, 69 m // 1.iv.2001, // leg. V. Bejček & K. Šťastný’. PARATYPES: 1 J 2 ♀♀, same label data as holotype (2 NMPC, 1 ECRI) ; 1 ♀, ‘ Yemen, Socotra Isl. N // Di Lishe beach, 20 m, // 2.ii.2010, // L. Purchart lgt.’ ( NMPC) .

Description. Male holotype. Body length 7.1 mm. Piceous, shining, antennae and tarsi dark brown, apical comb of setae of tibiae and claws honey-red. Disc of elytra, pronotum and head very sparsely covered by isolate recumbent whitish elongate scales intermingled with almost recumbent whitish to golden hair-like scales. Dorsal clothing appears abraded since on sides and on apical fifth of elytra scales are rather dense, and elongate ones here and there are more condensed in whitish spots or faint stripes. Ventral surface with quite sparse recumbent whitish and golden hair-like scales ( Fig. 60 ).

Head. Rostrum 1.17 times longer than wide, sides slightly converging from base to moderately protruding pterygia. Epifrons slightly convex, thinly and sparsely punctured at base and subrugose towards crescent weak sulcus situated between scrobes, at narrowest point about 0.75 times as wide as rostrum between antennal insertion, with barely visible trace of dorsal carina and with sides weakly keeled. Epistome U-shaped and distinct from epifrons by its smooth surface. Scrobes short, entirely visible in dorsal view, in lateral view low straight carina starts just basad of scrobe and almost reaches middle of eye. Head separated from rostrum by transverse concave sulcus, distance between eyes about same as that between antennal insertion, space between eyes faintly depressed and longitudinally sulcate, vertex convex, basally finely strigose and apically punctured, temples just little shorter than greater diameter of eye and subparallel sided. Eyes large, elliptical and convex. Antennae thin; scape almost straight and moderately clubbed; funicular antennomere I 1.80 times longer and hardly wider than II, antennomeres II to VII progressively diminishing in length, all longer than wide; club fusiform elongate, about as long as three preceding antennomeres.

Pronotum 1.28 times wider than long, widest just apicad of middle, quite flat dorsally in lateral view; anterior margin hardly narrower than flanged basal one; sides weakly rounded; disc with large, irregularly polygonal smooth flattened granules becoming smaller and sparser on sides and separated by coarsely punctured intervals. Scutellum broadly triangular, barely visible.

Elytra elongate-oval, 1.82 times longer than wide, about 1.78 times as wide as pronotum, moderately convex on basal half, apical declivity almost perpendicular; striae formed by rather uneven rows of irregularly subquadrate large punctures; intervals not wider than striae, quite smooth and little convex.

Legs elongate; femora clubbed, edentate, sparsely clothed by recumbent and slightly erect whitish setae, extreme base of profemora with barely visible very obtuse minute protuberance; protibiae quite strongly curved on apical half, mesotibiae moderately so, metatibiae with their apical half curved and somewhat twisted on side facing elytra so that their section is triangular there, and with rather obtuse tooth placed on internal side just basad of level where ends apical comb on external side, pro- and mesotibiae with erect long whitish thin setae on internal margin, those on metatibiae are on whole surface excepted internal flattened area facing elytra which is smooth and bare; tarsi robust with erect thin setae and stiff semirerect longer ones, tarsomere I longer and slightly wider than II which is longer than wide, tarsomere III bilobed and as long as wide, tarsomere IV projecting from third by about length of III, claws fused in basal half.

Ventral side. Metaventrite, abdominal ventrite I and base of ventrite II with large rather deep common impression, rest of ventrites convex in middle.Anterior and median right claws, and posterior claw segment missing.

Male genitalia. Aedeagus as depicted in Fig. 61 .

Variability. The other male is almost identical to the holotype, its right antenna, right median claws and half of left claw segment missing. Elytra of females are broadly oval and strongly convex on disc, their profemora lacking basal protuberance, the long erect setae of tibiae are missing, and their metafemora have no trace of apical incision. One of the females is slightly immature so that its left elytron is depressed at apical third, the antennae of the same specimen are broken, the left beyond funicular antennomere III, the right having only the base of scape. The other female lacks both antennal funicles. The rostrum of all paratypes is more evidently longitudinally keeled, on dorsum of elytra are more visible some whitish spots and some vague pearly-white lines on sides of elytral declivity.

Body length 5.6–7.5 mm.

Differential diagnosis. Nematocerus barbitibia sp. nov. and the other Socotran species, N. spinifemur sp. nov., are similar to the Somalian species Nematocerus globosus ( Gestro, 1892) , comb. nov., and N. humerosus ( Gestro, 1892) , comb. nov., both moved from Systates Gerstaecker, 1861 to Nematocerus Reiche, 1849 on account of their quite accurate descriptions by GESTRO (1871). Nematocerus barbitibia sp. nov. is close to N. globosus , described upon a single female from Eyl (Nugal province, Somalia), differing from it by the anterior margin of pronotum not clearly narrower than posterior one, dorsal carina of rostrum, if present, not anteriorly bifurcate, and lack of evident lateral white stripes on thorax and elytra, although the fairly poor condition of the types of N. barbitibia sp. nov. does not allow to be sure that this feature is truly constant. Nematocerus humerosus , described from Uebi (probably Uebi Shebeli, central Somalia) also based on a single female, differs immediately from the new species by its longitudinally strigose rostrum and transversely rugulose interocular space, trapezoid pronotum and dense greyish clothing of scales. The new species is also not unlike N. angustirostris (Aurivillius, 1926) from Eritrea and Somalia, but, apart from the different pattern and the much finer pronotal granules, male tibiae of this species do not show long setae or apical notch on their inner margin. See below for differences from the following species.

Etymology. The species name, a composite Latin noun barbitibia (meaning ‘bearded tibia’) in apposition, was chosen in reference to its setose male tibiae.

Distribution. Endemic to Socotra Island.

Figures

Figs 58–61. 58–59 – Ericiates cinereus sp. nov.: 58 – habitus of the holotype; 59 – aedeagus of a paratype in dorsal view. 60–61 – Nematocerus barbitibia sp. nov., holotype. 60 – habitus; 61 – aedeagus in dorsal view.