Canuschiza minuta Lacroix, 1999

Sehnal, Richard, Král, David & Bezděk, Aleš, 2017, Canuschiza of Socotra Island (Coleoptera: Scarabaeidae: Melolonthinae) Part 2. Canuschiza minuta species group, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 57, pp. 77-86 : 78-82

Canuschiza minuta Lacroix, 1999

( Figs 1A–L , 2A–F )

Canuschiza minuta Lacroix, 1999: 88 , figs 2, 12, 14, 16, 18, 20, 22, 24, 26 (original description); LACROIX (2002): 404, figs 13–17, 22–25 (review); BEZDĚK (2006): 228 (catalogue); LACROIX (2010): 207 (catalogue); SEHNAL et al. (2014): 168, fig. 1B (comparison); BEZDĚK (2016): 280 (catalogue).

Type locality. ʻSocotraʼ.

Type material examined. HOLOTYPE: J, labelled: ‘ HOLOTYPE [p, red label] || SOCOTRA | MISSION AURACEA | NOVEMBRE 1997 | J. G. CANU REC. [p, pale blue label] || Canuschiza | minuta n.sp. [h] | M. LACROIX det. 19 [p] 99 [h]’ ( MNHN, Figs 1A,I ).

Additional material examined (93 specimens). YEMEN: SOCOTRA ISLAND: Wadi Ayhaft , 12°36′38″N 53°58′49″E, 190 m a.s.l., 14.–26.xi.2003, D.Král leg., 1J 2♀♀ ( NMPC) ; Dixam plateau, Wadi Es Gego, 12°28′09″N 54°00′36″E, 300 m a.s.l., J. Farkač leg., 1 J ( NMPC) ; same data but D. Král leg., 1 J 2 ♀♀ ( IECA) ; same data but P. Kabátek leg., 2 JJ 1 ♀ ( RSCV) ; Wadi Es Gego , 12°28′18″N 54°00′34″E, 300 m a.s.l., 13.v.2004. A. Reiter leg., 1 J 7 ♀♀ ( NMPC) ; Dixam plateau, Wadi Zerig, 12°29.6′N 53°59.5′E, 655 m a.s.l., 13.–14.vi.2012, J. Bezděk, J. Hájek, V. Hula, P. Kment, I. Malenovský, J. Niedobová & L. Purchart leg., 32 JJ 5 ♀♀ ( NMPC), 10 JJ 5 ♀♀ ( IECA), 10 JJ 5 ♀♀ ( RSCV), 2 JJ 2 ♀♀ ( BMNH), 2 JJ 2 ♀♀ ( MNHN) .

Redescription. Male (holotype). Body elongate, almost parallel, remarkably convex. Dorsal and ventral surface moderately shiny, elytra somewhat alutaceous, chestnut brown, macrosetation pale ( Fig. 1A ). Dorsal surface of head, pronotum, scutellar shield and elytra covered with white short, remarkably minute recumbent scale-like macrosetae, ventral surface of thorax and abdomen with sparsely spaced, white recumbent scale-like macrosetae. Head appendages and legs covered with yellowish moderately long macrosetae, mixed with a few white recumbent scale-like macrosetae on metafemora.

Head. Labrum transverse, deeply bilobed, lobes rounded, irregularly and coarsely punctate, covered with long erect macrosetae. Clypeus transverse, anterior margin weakly upturned and shallowly sinuate, anterior angles rounded. Frontoclypeal suture present, forming continuous elevated carina. Clypeus and frons densely (to confluent), irregularly, coarsely punctate, each puncture with short, minute erect macroseta. Occiput sparsely, regularly, moderately punctate. Eye-canthus narrow, short, bare. Frons relatively narrow, width of frons / width of eye ratio = 2.02–2.28 (10 specimens measured). Antenna with nine antennomeres; club with three antennomeres, almost straight ( Fig. 1D ), distinctly shorter than antennal shaft (antennomeres I–VI combined). Antennomeres I–VI with sparse long macrosetae, club with sparse short macrosetae. Terminal maxillary palpomere elongate, apically rounded, approximately as long as palpomeres II and III combined.

Pronotum transverse, moderately convex, widest approximately in middle. Basal and lateral borders complete, anterior border missing. Lateral outline regularly rounded, margins not crenate, bare. Anterior margin regularly, broadly sinuate. Anterior angles moderately produced, obtuse-angular; posterior angles remarkably broadly rounded ( Fig. 1B ). Punctation consisting of coarse, umbilicate, almost regularly spaced punctures becoming somewhat denser laterad; each puncture bearing short, narrow, white scale-like, almost recumbent macroseta; transversal, weakly convex, nude area anteriorly of base present.

Scutellar shield large, almost equilaterally triangular, sides and apex round; disc punctate laterally, each puncture bearing short, narrow, white scale-like, almost recumbent macroseta.

Elytra weakly convex, parallel-sided, rounded apically, apical angle approximately rectangular. Striae missing, excepting feebly visible sutural stria. Humeral umbones present, vaguely swollen. Surface finely microsculptured (shagreened), alutaceous; punctation coarse, almost regularly spaced, punctures separated by 1–2 their diameter. Each puncture bearing short, narrow, white scale-like, almost recumbent macroseta. Epipleura distinct, complete, narrow, with several macrosetae in basal third.

Macropterous.

Legs. Femora narrow, shiny, irregularly punctate, almost nude. Protibia narrow, distinctly tridentate, terminal calcar inserted against emargination between medial and basal tooth. Meso- and metatibia slightly expanded apicad, with two macrosetiferous longitudinal and one obliquely transversal carinae. Upper terminal calcar of metatibia flattened, slightly curved, acute apically, almost two times as long as lower, apically truncate chisel-shaped metatibial calcar. Claws bifid, with ventrobasal teeth ( Fig. 1C ).

Ventral surface covered with sparsely spaced, short, recumbent, white scale-like macrosetae. Pygidium convex, all around bordered, apically broadly rounded, irregularly covered with coarse macrosetiferous punctures.

Male genitalia. Parameres symmetrical, approximately as long as phallobasis, regularly curved in lateral aspect, rounded apically in dorsal aspect; apex with tuft of long yellowish macrosetae ( Figs 1G,H ).

Sexual dimorphism. Female differs from male in the following characters: body slightly broadened posteriad ( Figs 2D–F ); antennal club straight, distinctly shorter ( Figs 1K,L ); metatibia more strongly expanded apically; tarsomeres of all legs shorter; claws shorter, more robust.

Variability. Material of both males and females slightly varies in length (see measurements), colour and punctation of dorsal surface, length and distribution of scale-like macrosetation of pronotum and elytra. In addition, all three specimens originating from Wadi Ayhaft are characterized by more wrinkled frons than those from Wadi Es Gego and Wadi Zerig; on the other hand specimens found in Wadi Zerig are characterized by blackish coloured terminal parts of scapus and pedicellus and by dorsal surface irregularly bicolorous with dark elytral suture ( Figs 2C,F ) while specimens from Wadi Ayhaft and Wadi Es Gego are predominantly unicolorous (incl. brownish scapus and pedicellus). Seven female specimens from Wadi Zerig have only eight antennomeres in both antennae. Despite the above mentioned differences, these specimens are tentatively considered conspecific because of identical shape of the aedeagus.

Measurements. Total body length: JJ 6.5–7.5 mm (holotype 7.5 mm); ♀♀ 6.8–8.5 mm.

Collecting circumstances. As far as it is known, the majority of specimens was captured attracted to light (J. Bezděk, pers. comm.); all specimens collected by A. Reiter were found climbing on vegetation after the dusk (A. Reiter, pers. comm.).

Geographical distribution. Endemic species of the Socotra Island, so far known from Wadi Ayhaft, Wadi Es Gego and Wadi Zerig. See BEZDĚK et al. (2012) for precise location.

Remarks. Line drawings of the holotype parameres accompanying the original description ( Figs 1E,F ; see also LACROIX (1999: fig. 2) for originals) do not entirely correspond to reality, mainly in the lateral aspect. Dark colouration of the holotype is probably unnatural as the type specimen appears to be partly rotten.

Out of 19 female specimens collected in Wadi Zerig area, seven exhibit reduction of antennomere number to eight in both antennae. This is due to the fusion of two antennomeres, most likely between antennomere III to V. An analogous situation is to be found relatively frequently in several members of Rhizotrogini, for more details see e. g. BRANCO (1990), BUNALSKI (1994), COCA- ÁBIA (1992) or MONTREUIL (2000), but so far has never been recorded in the tribe Schizonychini .

Figures

Figs 1A–L. Canuschiza minuta Lacroix, 1999: A–I – male, holotype, body length 7.5 mm; J–K – female, specimen from Zerig, body length 7.2 mm; L – female, another specimen from Zerig. A – habitus; B, J – pronotum in lateral and dorsal views; C – protarsal claw; D – antenna; E, F – aedeagus in dorsal and lateral views (adopted and modified from LACROIX 1999); G, H – aedeagus in dorsal and lateral views; I – labels; K – antenna with eight antennomeres; L – antenna with nine antennomeres. Not to scale.

Figs 2A–F. Canuschiza minuta Lacroix, 1999, dorsal view: A – male, specimen from Esgego, body length 7.0 mm; B – male, specimen from Ayhaft, body length 7.5 mm; C – male, specimen from Zerig, body length 7.2 mm; D – female, specimen from Esgego, body length 7.4 mm; E – female, specimen from Ayhaft, body length 8.5 mm; F – female, specimen from Zerig, body length 7.2 mm. Not to scale.