Nesotocerus labeculatus, 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 : 361-364

Nesotocerus labeculatus sp. nov.

( Figs 73–75 )

Type material. HOLOTYPE: J ( NMPC), ‘ Yemen, Socotra // Dixam plateau Firmihin // ( Dracaena forest), 490 m // 12°28.6′N, 54°01.1′E // 15-16.xi.2010 // P. Hlaváč leg.’. PARATYPES: 9 JJ 4 ♀♀, same label data as holotype (9 NMPC, 2 BMNH, 2 ECRI); 2 JJ 4 ♀♀, ‘ Socotra Is. ( YE) Dixam plateau // Firmihin ( Dracaena forest), 490 m // 12°28.6′N, 54°01.1′E, // 15-16.xi.2010 Jan Batelka leg.’ (5 JBCP, 1 ECRI); 1 J, ‘ Yemen, Socotra Island // Firmihin, 400-500 m // N 12°28′27″, E 54°0′54″ // 22-25.vi.2009 // J. Purchart & J. Vybíral lgt.’ ( NMPC); 3 JJ 2♀♀, ‘ Yemen, Socotra Isl., // Dgisfu valley, 2.vi.2010 // N 12°28,444′, E 054°08,596′ // V. Hula & J. Niedobová leg.’ (4 NMPC, 1 ECRI); 1 J, ‘ Yemen, Socotra Island // Zemhon area, 270-350m // N 12°30′58″, E 54°06′39″ // 3-4.ii.2010 // L. Purchart & J. Vybíral lgt.’ ( NMPC); 2 ♀♀, ‘ Yemen, Socotra Island // Diksam plateau, 850-920 m // N 12°31′24″, E 53°58′29″ // 5.ii.2010 // L. Purchart & J. Vybíral lgt.’ (1 NMPC, 1 ECRI); 9 JJ 7 ♀♀, ‘ Yemen, Socotra // Aloove area, Hassan vill. // env. 221 m // 12°31.2′N, 54°07.4′E 9- // 10.xi.2010 P. Hlaváč’ (10 NMPC, 6 ECRI); 2 JJ 1 ♀♀, ‘ Yemen, Socotra Island //Aloove area, Hassan vill. env.// 12°31.2′N, 54°07.4′E, 221 m // Jiří Hájek leg. 9-10.xi.2010 ’ (2 NMPC, 1 ECRI); 8 JJ 9 ♀♀, ‘ Socotra Is. ( YE) // Aloove area, Hassan vill. env. // 12°31.2′N, 54°07.4′E, 221 m // Jan Batelka leg. 9-10.xi.2010 ’ (14 JBCP, 3 ECRI); 7 JJ 13 ♀♀, ‘ Yemen, Socotra Island // Aloove area, Aloove vill. env. // Jatropha unicostata shrubland; // with Boswellia elongata trees // 19-20.vi.2012 // 12°31.2′N, 54°07.4′E, 221 m’, ‘ Socotra expedition 2012 // J. Bezděk, J. Hájek, V. Hula, // P. Kment, I. Malenovský, // J. Niedobová & L. Purchart leg.’ (16 NMPC, 5 ECRI); 1 J, ‘ Socotra ( Yemen) // Wadi Ayhev 250 m // 10.iv.2008 // leg. A. Carapezza’ (15 NMPC, 5 ECRI); 1 ♀, ‘ Yemen, Socotra island // Homhil, protected area // open woodland with Boswellia & // Dracaena trees; 10–11.vi.2012 // 12°34.5′N, 54°18.5′E, 360–500 m’, ‘ Socotra expedition 2012 // J. Bezděk, J. Hájek, V. Hula, // P. Kment, I. Malenovský, // J. Niedobová & L. Purchart leg.’ ( NMPC); 1 ♀, ‘ Yemen, Socotra Island // Deiqub cave, 12.vi.2012 // cave & Croton socotranus + // Jatropha unicostata shrubland; // 12°23.1′N, 54°00.9′E, 115 m’, ‘ Socotra expedition 2012 // J. Bezděk, J. Hájek, V. Hula, // P. Kment, I. Malenovský, // J. Niedobová & L. Purchart leg.’ ( NMPC).

Description. Male holotype. Body length 5.6 mm. Piceous, rather shining, tibiae in pars, tarsi and apical five antennomeres of funiculus brown, claws ferruginous. Dorsal surface of rostrum, head and pronotum sparsely covered by recumbent light grey to dirty yellowish elongate scales. Sides of rostrum, upper and under margins of eyes and sides of prothorax with dense partly embricate triangular to elongate golden-yellowish scales forming kind of lateral pale stripe. Elytra with moderately dense recumbent elongate mottled brownish and yellowish-golden elongate scales; at beginning of elytral declivity there is broadly V-shaped pale band formed by some irregular spots larger of which are on intervals III and V, besides row of clavate elongate scales recumbent on disc and erect on lateral intervals. Some long curved erect setae are at base of intervals VI and specially VII. Ventral surface with rather sparse somewhat erect whitish hair-like scales less dense in middle ( Fig. 73 ).

Head. Rostrum about as long as wide, sides feebly converging from base to apical two thirds of rostral length, then fairly widening towards apex; pterygia moderately prominent. Epifrons scarcely depressed, moderately densely punctured, with barely visible basal carina ending little apicad of level of its narrowest point which is 0.49 times as wide as rostrum, sides keeled. Epistome U-shaped and separated from epifrons by rather deep V-shaped sulcus. Scrobes short, entirely visible in dorsal view. Head separated from rostrum by shallow sulcus only visible at sides, interocular distance about same as that between antennal insertion, space between eyes faintly depressed and with longitudinal sulcus ending between eyes, vertex almost flat, basally finely strigose and apically sparsely punctured, temples about two times shorter than greater diameter of eye and subparallel sided. Eyes large, somewhat elliptical and moderately convex. Antennae rather thin; scape almost straight and moderately clubbed; funicular antennomere I twice as long and barely wider than II, antennomeres II to VII progressively diminishing in length, all distinctly longer than wide; club fusiform elongate, about as long as three preceding antennomeres.

Pronotum 1.24 times wider than long, widest just apicad of middle, flat dorsally in lateral view; anterior margin almost as wide as somewhat flanged basal one; sides moderately rounded; disc with large irregularly roundish smooth flattened granules becoming little smaller and denser on sides and with shallow median low carina on apical half. Scutellum extremely minute, almost invisible.

Elytra elongate-oval, 1.45 times longer than wide, 1.78 times as wide as pronotum, maximum width at basal third, disc almost flat, apical declivity abrupt and ending with slightly acute angle; striae formed by rather regular rows of irregularly subquadrate large punctures; intervals not wider than striae, surface quite irregular and little convex, interval VII with some acute rasp-like granules on apical quarter.

Legs moderately elongate, rather sparsely clothed by partly erect whitish setae and partly recumbent narrowly elongate scales which also form pale femoral white middle ring; tibiae slightly curved inwards towards apex and with some stiff blackish setae originating from minute rasp-like granules, particularly numerous on metatibiae, all tibiae with apical mucro, one of protibiae minute, whereas that of meso- and particularly of metatibiae is rather acute; tarsi robust with rather sparse erect thin and stiff semirerect longer setae, 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 III by little more length of III.

Ventral side with recumbent narrowly lanceolate quite sparse whitish scales on prosternum and mesoventrite, metaventrite and abdominal ventrites with some slanted sparse hair-like setae in middle; metaventrite and ventrite I with large common median depression.

Variability. Paratypes are very similar to the holotype, their dorsal pattern being more or less evident. Elytra of females are broader and more convex ( Fig. 74 ), and their abdomen has no depressions.

Male genitalia. Aedeagus as depicted in Fig. 75 .

Body length 4.1–7.8 mm.

Differential diagnosis. This species is readily differentiated from the other three Socotran Nesotocerus species by its peculiar dorsal pattern with U-shaped band at the beginning of elytral declivity and here with erect scales not longer than the width of one elytral interval. Most of the males from Aloove area have elytra more flattened than those of the holotype. See also the key below. It is possible that the female specimen of Nesotocerus sp. figured by WRANIK (2003: pl. 178, fig. d) as ‘ Parasystates sp. ’ belongs to this relatively common weevil.

Etymology. The species name, Latin adjective labeculatus (- a, - um), meaning ‘bearing stain, blemish’, refers to the maculate band of the elytra.

Distribution. Endemic to Socotra Island.

Figures

Figs 73–78. 73–75 – Nesotocerus labeculatus sp. nov.: 73 – habitus of the holotype; 74 – habitus of a female paratype; 75 – aedeagus of a paratype in dorsal view. 76–78 – Nesotocerus griseovestitus sp. nov.: 76 – habitus of the holotype; 77 – habitus of a female paratype; 78 – aedeagus of a paratype in dorsal view.