Orthogonius gracililamella Tian, Deuve & Felix sp. n. Figures 620

Diagnosis.

Moderate or small sized, member of the Orthogonius longicornis species group, eyes very large; mentum asetose; apex of elytra shortly and obliquely truncate at inner margin of the tip to form an obvious sutural angle between elytra; labrum slightly emarginate at frontal margin; prosternal process bordered at apex, base of elytra complete; hind tarsomere 4 slightly emarginate at apex, hind femur quite slender, with two setae posteriorly, all tarsal claws strongly pectinate; ventrite VII very slightly emarginate at apical margin; aedeagus with apical lamella long and parallel-sided.

Length: 12.0-13.0 mm; width: 5.0-5.5 mm. Habitus as in Figure 6.

Description.

Light dark brown (HT) to black (PT), palps, antennae, lateral expanded margin of pronotum, tibiae, femora and trochanters lighter.

Wrinkles and punctures: surface impunctate except elytral intervals 3, 5 and 7 with tiny, and sparse punctures arranged as a row, head wrinkled, pronotum faintly striate.

Microsculptural meshes isodiametric on elytra, head and pronotum.

Head as long as wide, eyes very large, strongly prominent; frons and vertex convex, frontal impressions faint, clypeus bisetose, even; labrum quadrate, sexsetose, frontal margin slightly emarginate at frontal margin; mandibles well developed; ligula small and narrow, bisetose at apex; palpi slender, subcylindrical, maxillary palpomere 3 as long as 4, glabrous; labial palpomere 2 longer than 3, 2-setose in inner margin; labial palpomere 3 sparsely pubescent; palpiger asetose, mentum asetose, and submentum with one pair of setae; mentum without median tooth. Antennae extended to near basal 1/4 of elytra; pubescent after basal 1/4 of antennomere 4, antennomeres 4-5, slightly dilated, antennomere 3 shorter than 4 (about 0.7 times as its length).

Pronotum strongly transverse, PW/PL=1.56, moderately convex; sides evenly rounded, widest at about middle, both basal and fore margins beaded, lateral expanded margins well defined, uneven, slightly reflexed; fore and hind angles rounded; fore transverse impression unclear, hind one distinct, basal foveae small, but well marked, middle line clear.

Elytra ovate, EL/EW=1.60, convex, basal border complete, sides slightly expanded, not parallel at middle, striae deep, intervals convex, intervals subequal in width in middle; apex roundly truncate, but shortly and obliquely truncate at inner margin of the tip to form an obvious sutural angle between elytra; interval 3 with three setae, all are well marked; interval 7 not carinate, without seta.

Middle coxa glabrous in median portion; hind coxa with two setae. Legs moderate, fore tiba with outer angle rectangular, serrate on outer margins, apical margin oblique; middle tibia straight in middle, abruptly dilated at apex; hind tibiae slender, slightly dilated only at apex; hind tibial spurs very long and sharp; tarsomere 4 much longer than tarsomere 3 (almost 1.25 times as long), tarsomere 4 very shallowly emarginate at apex; hind femora rather slender, with two setae posteriorly; all tarsal claws strongly pectinate.

Prosternal process well bordered at apex. Apical margin of abdominal ventrite VII very shallowly and slightly emarginate.

Male genitalia (Figure 20): Moderately elongate, ventral margin more or less sinuate ventrally, apex pointed in lateral view; in dorsal view, apical lamella very long and nearly parallel-sided.

Female. Unknown.

Remarks.

The apical portion of the aedeagus is very elongate, a little more twisted in the holotype than in the paratype, and the apical lamella is slender and parallel-sided, with the apex broadly rounded.

Material examined.

Holotype: male, "Thailand: Loei: Phu Kradueng NP, Huay Lao Kao, 16° 52.442N, 101° 50.706E, 280 m, Malaise trap, 29-30.viii.2006, Sutin Khonglassae leg. T490", in QSBG.

Paratype: 1 male, "Thailand: Chaiyaphum: Tat Tone NP, water supply station at Taad Fah waterfall, 15° 56.468N, 102° 05.855E, 245 m, Malaise trap, 5-12.ix.2006, Tawit Jaruphan & Orawan Budsawong leg., T686", in QSBG.

Etymology.

The name refers to the long and narrow apical lamella of aedeagus.

Distribution.

Thailand. Known only from the type locality.