Thesilea cyaneothorax, Ando, Kiyoshi & Ruzzier, Enrico, 2016

Ando, Kiyoshi & Ruzzier, Enrico, 2016, New species of Tenebrionidae Latreille, 1802 (Coleoptera: Tenebrionoidea) from the Philippines, Zootaxa 4175 (5), pp. 480-486 : 484-485

Thesilea cyaneothorax sp. nov.

( Figs. 3A, B )

Type material. Holotype: male, Philippines, Belance , Nueva Viscaya, Luzon, VIII. 2013, Native collector leg. ( BMNH).

Description. Dimensions. Body length. 12.5 mm. IE/TD = 2.73; PW/PL = 1.27; EL/EW = 1.89.

Male. Elongate, moderately convex, shiny. Colour black; head aeneous, mingled with metallic green sheen; antennae infuscate apically and dark reddish brown basally; pronotum violet-blue, with greenish reflection; elytra reddish purple, with epipleura metallic green; venter with strong metallic violet-blue and/or metallic green reflection; femora with reddish purple reflection; mouthparts and tarsi dark reddish brown ( Fig. 3A ).

Head hexagonal, moderately convex, anterior margin between frontoclypeus and genae angulate; clypeus weakly convex, densely, finely punctate, distinctly emarginate at apex, with both lateral angles roundly produced antero-ventrally; fronto-clypeal suture fine, evenly arcuate; genae wider than long, slightly convex, evenly narrowed towards apex; frons broad, gently convex, densely punctate, punctures semiumbilicate, larger than on the anterior part of the head; eyes rounded, distinctly convex, inner ocular sulci deep and distinct, slightly broadened posteriorly. Antennae reaching before base of pronotum; five distal antennomeres distinctly dilated, forming a robust club. Ultimate maxillary palpomeres right-angled triangular, slightly emarginate at apex. Mentum transversely elliptical, weakly convex in middle and shallowly emarginate at apex, with some setiferous punctures.

Pronotum subquadrate, weakly convex, widest before middle; anterior margin weakly emarginate, slightly produced in median three-fifths, very finely bordered in the lateral portions; lateral margins gently narrowed forwards and evenly narrowed backwards from the widest point, thickly bordered, with rather uneven surface; basal margin weakly bisinuate, broadly and slightly produced in middle, moderately bordered; anterior angles produced, obtusely angulate, posterior angles acutely pointed, a little produced laterally; disc gently sloping laterally, unevenly flattened and not sulcate along lateral margins, coarsely, sparsely and irregularly punctate, punctures as same in size as to and/or larger than on frons. Scutellum linguiform, weakly convex, finely punctate.

Elytra oblong, distinctly wider than pronotum at base, gently divergent posteriorly, widest at apical third, distinctly convex above, depressed behind scutellum; striae fine, weakly depressed; strial punctures sparse and fine, stronger anteriorly and finer posteriorly; intervals weakly convex, a little strongly so in apical portions, very finely and sparsely punctate; humeral calli strongly and broadly humped laterally; epipleura flat, broadened and oblique in basal portions, microsculptured and impunctate.

Prothoracic hypomera unevenly roughened, very coarsely and strongly punctate. Prosternum rather short, coarsely and irregularly punctate; prosternal process subparallel-sided, flattened, weakly sloping, rounded at apex, with some coarse punctures. Mesoventrite densely and irregularly punctate; V-shaped ridge short and broad, obtusely rounded and not angulate at anterior portions, irregularly rugulose and punctate. Metaventrite strongly convex in middle, steeply sloping laterally, very finely and microscopically punctate. Abdomen convex in middle, rather coarsely punctate in three basal visible sternites and finely so in the rest; fifth ventrites depressed along base, elliptically flattened in middle.

Aedeagus robust, gently curved in lateral view; basal piece lanceolate, distinctly constricted behind apex, with apical angles acutely produced and distinctly curved dorsal; parameres drop-shaped, depressed ( Fig. 3B ).

Legs moderately elongate; femora weakly clavate, posterior margin of metafemora weakly emarginate in basal half; tibiae short, densely and coarsely punctate, inner margin of meso- and metatibiae suddenly broadened behind base, with dense setae in apical two-thirds, those of mesotibiae strongly incurved before apex.

Female. Unknown.

Etymology. cyaneothorax from latin “cyaneus” adjec. = blue coloured, plus “thorax”= thorax referred to the pronotum.

Diagnosis. T. cyaneothorax sp. nov. can be easily separated from most of the Philippine species by having pronotum of different colouration than the elytra. The other two species with a similar combination of colours, T. ruficollis and T. varicolor can be separated from the latter by the following characters: red head and pronotum in T. ruficollis , blue in T. cyaneothorax sp. nov.; pronotum with irregular, sparse punctures and anterior angles of the pronotum produced in T. cyaneothorax , pronotum with dense, homgeneous puntures and anterior anges of the pronotum rounded in T. varicolor .

The new species resembles T. chrysoptera Kulzer, 1951 (typ. loc. Sumatra) due to its blue pronotum and differently coloured elytra, but differs from the latter in the following characters: head coarsely and not finely punctate; anterior margin between anterior part of head and genae distinctly angulate, not depressed near the anterior margin of the eyes; frontoclypeus distinctly emarginate at apex; mentum transversely elliptical; pronotum emarginate at the anterior margin, with posterior angles acute; elytra distinctly wider than pronotum at base, with purple sheen.

Taxonomic note. Thesilea varicolor var. unicolor Kulzer 1951 should be interpreted and treated as subspecies following Art. 45.6 of ICZN: Thesilea varicolor unicolor Kulzer 1951 .

Figures

FIGURE 3 A, B. Thesilea cyaneothorax sp. nov., holotype. A—habitus in dorsal view, scale bar 5 mm. B—aedeagus in dorsal (left) and lateral view (right), scale bar 1 mm.