Mecynotarsus excavatus Kejval & Cz 2013, sp. nov.

Mecynotarsus excavatus sp. nov.

(Figs 44–46, 130, 134, 137, 149, 174, 193)

Type locality. New Caledonia, Touho-Koné, Aoue-Enga.

Type material. HOLOTYPE: ♂, ‘ Nouvelle Calédonie m 60 str. Touho-Koné, Aoue-Enga, 24.II.2006 P. M. Giachino leg. [p]’ (SMNS). PARATYPES: 9 ♂♂ 3 ♀♀, same data as holotype (SMNS, 3 spec. ZKDC, 1 spec. NMPC); 1 ♂, ‘ Nouvelle Calédonie str. Touho-Koné 24.II.2006 - m 150 M. Daccordi leg. [p]’ (SMNS); 1 ♀, ‘ NEW CALEDONIA, 50 m, Bourail, 30.12.- 5.1.1991, leg. Wiesner & Worm [p; violet label] // Notoxus decemdentatus Pic det. G. Uhmann 1991 [p+h]’ (ZKDC); 4 ♂♂ 4 ♀♀, ‘ NEW CALEDONIA (N) 20°25.2′S 164°13.3′E Nehoue river, 15 m 8.01.2007 public camp site night coll. (lamp & beating) leg. M. Wanat & R. Dobosz [p; black frame] // Muzeum Przyrodnicze Uniwersytetu Wroclawskiego MNHW Museum of Natural History Wroclaw University [p]’ (MNHW); 1 ♂ 1 ♀, ‘ NEW CALEDONIA (N) 20°25.2′S 164°13.3′E Nehoue river, 15 m 8.01.2007 public camp site leg. R. Dobosz & M. Wanat [p; black frame]’ (USMB); 1 ♀, ‘ NEW CALEDONIA: 4 km W. of Thio black light 24 Dec. 1976 G. F. Hevel [p] // Leptoprion? [h; black frame]’ (DCDC).

Description (holotype, male). Body length 3.3 mm. Body black, at places brownish; legs and antennae brown to dark reddish brown.

Head vertex with rather distinct, deep median incision / cavity (Fig. 130). Antero-lateral margins of frons simple. Gular rugules minute and scattered. Clypeal granules indistinct. Setation of head largely uniformly scaly, with some longer, hair-like setae ventrally; scales minute, very densely spaced, appressed.Antennae rather moderately long, at most very slightly enlarged in apical third; antennomeres III–V about twice, X nearly 1.3 times as long as wide; setation mostly rather short and fine, coarser to scaly on basal two antennomeres.

Pronotum nearly 1.9 times as long as wide, its lateral margins somewhat unevenly, moderately convex in dorsal view; posterior collar very narrow, inconspicuous. Pronotal horn moderately long, rather narrow (especially at base), its posterior angles obsolete in dorsal view (Fig. 149); horn margins armed with 4 rounded lobules on each side, with small additional granule situated on each side posteriorly, apical lobule wide and with small median incision, nearly bilobed; horn crest distinct, clearly raised, long and very narrow, with coarse, separate rugules on margins; submarginal rugules distinct, situated rather anteriorly; median rugules absent. Setation of pronotal disc silvery and scaly; scales similar to those on head, very small and uniform, rounded apically and quite appressed; antebasal paired setae absent, another tactile setae absent.

Elytra 1.8 times as long as wide, obliquely subtruncate apically; omoplates slightly indicated, postbasal impression absent. Surface with conspicuously large, at places somewhat serial punctures, becoming smaller towards elytral apices. Setation silvery, scaly, clearly double, appressed and evenly developed, comprised of large scales arising from coarse punctures, and small scales covering interspaces (Fig. 174); large scales oval, flake-like, small scales identical with those of head and pronotum; erect tactile setae absent.

Male characters. Head vertex with rather distinct deep median incision / cavity. Protibiae with small tooth-like subapical tubercle on inner side (Fig. 137). Sternum VII conspicuously modified (Fig. 44). Tergum VIII truncate posteriorly (Fig. 45). Aedeagus as in Fig. 46.

Variation. Body length (♂ ♀) 3.1–3.3 mm; pronotal horn with 3–6 lobules on each side, apical lobule usually distinctly bilobed. Elytra in females distinctly excavate apically (Fig. 134).

Differential diagnosis. Mecynotarsus excavatus sp. nov. is a very conspicuous species, showing a number of unique external characters: coarse elytral punctures with rounded, flake-like scales; elytra obliquely truncate (male) to excavate (female) apically; head vertex in male with rather distinct, deep median incision or cavity; male protibiae with small toothlike subapical tubercle on inner side. Moreover, it possesses a quite distinctive morphology of male sternum VII, tergum VIII, and the aedeagus.

Etymology. The species name is a Latin adjective, excavatus, -a, -um (= hollowed); named in reference to the presence of the small median cavity on the head vertex of males, and the excavate elytral apices of females.

Distribution. New Caledonia.