Corticeus socotranus, Purchart & Schawaller, 2012

Purchart, Luboš & Schawaller, Wolfgang, 2012, A new species of the genus Corticeus (Coleoptera: Tenebrionidae) from Socotra Island, Acta Entomologica Musei Nationalis Pragae 52, pp. 315-322 : 317-319

Corticeus socotranus sp. nov.

( Figs. 1–2 )

Type locality. Yemen, Socotra Island, Firmihin.

Type material. HOLOTYPE [unsexed] ( NMPC), labelled: YEMEN, SOCOTRA Island, Dixam plateau, Firmihin ( Dracaena forest), 12°28.6′N, 54°01.1′E, 490 m, Jiří Hájek leg., 15-16.xi.2010. PARATYPES. (11 specimens NMPC, 2 SMNS, 1 LPCB): same data as holotype; (1 NMPC): same data as holotype, P. Hlaváč leg.; (6 JBCP): same data as holotype, Jan Batelka leg.; (6 LPCB, 2 SMNS): YEMEN, SOCOTRA Island, Firmihin, 400-500 m, N 12°28′27′′E 54°0′54′′, 22.-25. vi. 2009, L. Purchart lgt.; (2 LPCB): YEMEN, SOCOTRA Island, Wadi Zirik, 650-670 m, N 12°29′35′′E 53°59′28′′, 16. vi. 2009, L. Purchart lgt.; (1 LPCB): YEMEN, SOCOTRA Island, Al Haghier Mts., Scant Mt. env., 1300-1500 m, 12°34.6′N, 54°01.5′E, 31.i.-1.ii.2010, L. Purchart lgt; (1 CULS): Yemen: Soqotra Is., 2.-3.xii.2003, Dixam plateau, WADI ESGEGO, N 12°28′09′′ E 54°00′36′′, 300 m [GPS]; Jan Farkač lgt., YEMEN - SOQOTRA 2003 Expedition; Jan Farkač, Petr Kabátek & David Král; (6 LPCB, 3 SMNS): 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.; (1 BMNH, 1 HNHM, 8 LPCB, 2 SMNS, 1 ZSM): YEMEN, SOCOTRA Island, Dixam plateau 14.-15.vi.2012, FIRMIHIN, Dracaena woodland, 12°28.6′N, 54°01.1′E, 490 m, SOCOTRA expedition 2012, J. Bezděk, J. Hájek, V. Hula, P. Kment, I. Malenovský, J. Niedobová & L. Purchart leg.; (3 BMNH, 3 HNHM, 14 LPCB, 5 NMPC, 6 SMNS, 3 ZSM): YEMEN, SOCOTRA Island, Dixam plateau, wadi ZERIG, pools, Juncus marsh; Dracaena trees; cave, 13.-14.vi.2012, 12°29.6′N, 53°59.5′E, 655 m, SOCOTRA expedition 2012, J. Bezděk, J. Hájek, V. Hula, P. Kment, I. Malenovský, J. Niedobová & L. Purchart leg.; (2 LPCB): 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.

Description. Small, body narrow and parallel. Dorsal as well as ventral side of body dark brown with labrum, antennae, and legs pale brown.

Measurements. Body length: 3.1–4.1 mm (holotype 3.1 mm); width: 0.8–1.0 mm (holotype 0.8 mm). Ratios: Pronotal width/length 0.81. Elytral length/width 2.25–2.40; elytral length /pronotal length 2.14–2.15; elytral width /pronotal width 1.08–1.18. Width of frons/width of one eye 2.00–2.23. Length of antenna/width of head 1.17–1.29.

Head with large eyes, glabrous, entire surface punctate. Narrower than widest part of pronotum. Genae with longitudinal depression along the outer margin. Frontoclypeal suture indicated by transverse depression. In dorsal view, distance between eyes twice as wide as their diameter.Antennae relatively short, shorter than pronotum in ratio 1.16; claviform, serrate and covered with short yellow setae. Antennomeres I, II and IV as wide as long. Antennomere III distinctly longer than broad. Antennomeres V–X club-like widened, strongly transverse, trapezoid. Apical antennomere globose.

Pronotum glabrous, smooth, much longer than broad, strongly widened towards anterior margin. Broadest in anterior third. Entire surface of pronotum simply and densely punctate. Space between those punctures approximately as large as eye facet. Pronotum completely rimmed, obliterated only in middle of anterior margin. Prothoracic hypomeron glabrous, smooth and finely punctate, similarly to surface of pronotum.

Elytra smooth, glabrous, parallel-sided and in dorsal view with slightly narrowed apex. Entire surface simply, finely and regularly punctate with punctures arranged in rows. Scutellum small with several small shiny granules. Elytral suture shallowly but conspicuously depressed behind scutellum. Shoulders strongly developed, rectangular.

Pygidium rounded, densely punctate, covered with short yellow setae.

Ventral part. Prosternum glabrous, shagreened, finely punctate. Prosternal process narrow between coxae, distinctly broadened and bent upward behind coxae. Mesoventrite glabrous, shagreened and roughly punctate. Metaventrite glabrous, inconspicuously shagreened and very finely and scarcely punctate. Abdominal ventrites 1–4 glabrous, finely and scarcely punctate with laterally situated groove on each side. Apical ventrite densely punctate, laterally without grooves and with several yellow erected setae apically.

Legs short. Apical half of tibiae covered with yellow setae. Pro- and mesotibia with sharp edge terminating latero-apically with small and acute spine-like tooth.

Aedeagus see Fig. 2 .

Differential diagnosis. Corticeus socotranus sp. nov. is a member of the C. longicollis -group and can be distinguished as follows: from Corticeus voluptuosus Bremer, 1995 it differs in the absence of colour spots on elytra (red-yellow spots on elytra in the latter species). With C. longicollis , C. constrictus (Gebien, 1921) and C. glabratus (Kolbe, 1898) it shares punctate, micro-reticulated (and therefore dull) and, in contrast to genae, raised clypeus. This feature separates the new species together with the latter three species from the remaining members of the longicollis -group, where the clypeus is flat (not raised) and shiny. From C. longicollis it differs in its constantly dark brown body and shorter pronotum (for ratios see Tab. 1). In C. longicollis the pronotum is longer, body yellow, brown or often with dark-brown to black frons, pronotum and pygidium, and with yellow elytra. With C. constrictus and C. glabratus it shares uniformly coloured body, which is black to black-brown in the latter two species. Besides, these two species possess much longer pronotum (Tab. 1). For comparison see also figures of the mentioned species (except C. constrictus ) in SCHAWALLER (2010).

Etymology. The name refers to the island’s name Socotra where the new species occurs.

Biology. Most specimens of the new species were found under the bark of fallen Dragon Blood Tree – Dracaena cinnabari Balf. f. (family Asparagaceae ), usually in a wet layer and in the company of Cossonus sp. weevils ( Curculionidae ). Several specimens (Aloove area) were found during the night walking on the bark of fallen Boswellia elongata Balf. f. (family Burseraceae ) trees together with large amount of Scolytinae beetles. Corticeus beetles together with their larvae are usually feeding on the exuding sap and detritus under bark in the galleries of bark beetles ( Curculionidae : Scolytinae ).

Distribution. Yemen, Socotra Island.

Figures

Figs. 1–4. Corticeus socotranus sp. nov. 1 – habitus in dorsal view; 2–4 – aedeagus (2 – lateral view; 3 – dorsal view; 4 – ventral view).