Ectatoderus nigrofasciatus Tan & Wahab, new species

(Figs. 5–7)

Material examined. Holotype, male (BRU.19.70), BRUNEI DARUSSALAM, Belait District, Jalan Labi near Andulau Forest Reserve, N4.63354, E114.51047, 76.6±5.0 m.a.s.l., on rattan foliage, 7 July 2019, 2042h, coll. M. K. Tan (UBDM).

Diagnosis. The new species is characterised by the scapus being dorsally black but ventrally and laterally brown, and the antennae being wholly black; the head has a distinct black band behind eyes; and the male phallic complex has the medial valve elongated, not curved to a spiral, sinuous both dorso-ventrally and laterally and with the ventro-external sclerite of the lateral valve being elongated, in basal third broader, and tapering into a narrow lamella with subacute apex.

The new species is closest in distribution to E. angusticollis Chopard, 1969 from Singapore. In both species the pronotum is more strongly widening apicad, and fore and middle tibiae are provided with black dorsal stripes. The new species differs by the scapus and antennae being black instead of testaceous, by the head being provided with a distinct black band behind eyes and by the male phallic complex having the medial valve not curved to a spiral.

The new species is most similar to E. argentatus Ingrisch, 2006 from Thailand having the pronotum strongly widening apicad and the frons dark; it differs by the darked scapus and basal antennal segments instead of being yellow brown, by the male phallic complex which is more elongated and having the medial valve sinuous rather than curving upward (basally) and by the shape of the apical sclerotization of the medial valve.

This new species also differs from E. samui Ingrisch, 2006 from Thailand by the pronotum being more strongly widening apicad and by the male phallic complex having the medial valve not curved to a spiral; from E. marginatus Bey-Bienko, 1966 from Lesser Sunda Islands it differs by the pronotum being more strongly widening apicad.

Etymology. The species name refers to the black band posterior of eyes and the black scapus (dorsally only) and antennae; nigro = black in Latin, fascia = band in Latin.

Description. Habitus of male as shown in Fig. 5. Dorsum of head flattened (Figs. 6A, 6B). Frontal rostrum 1.3 times wider than scapus (Fig. 6A). Maxillary palps with apical (= fifth) and subapical (= fourth) segments of subequal length, third segment longer than apical and subapical segments; apical segment triangular and widened apically (Fig. 6B). Pronotum about 1.7 times longer than wide with anterior dorsal margin narrow and straight; lateral margin widening posteriorly; strongly produced posteriorly and covering near-entirely tegmen; posterior margin convex. Fore tibia with internal tympanum small and oval; without external tympanum. Hind femur 1.1 times longer than hind tibia; hind tibia 4.4 times longer than hind metatarsus.

Male. Supra-anal plate with last abdominal tergite and epiproct distinctly separated by a transverse suture; last abdominal tergite transverse, with hind margin emarginate; supra-anal plate less transverse than last abdominal tergite, flattened, with fewer setae, apex rounded (Fig. 6E). Genitalia as in Fig. 7. Epiphallus elongated and membranous. Medial valve elongated, not curved to a spiral, sinuous both dorso-ventrally and laterally. Lateral valves weakly sclerotised, forming stout and truncated lobes at apex. Ventro-external sclerite of lateral valve elongate, basal third broader, tapering into a narrow lamella with subacute apex.

Female. Unknown.

Colouration. Head dorsum light brown, with white stripe running along lateral margin from posterior end, along inner margin of eyes to frontal rostrum (Figs. 6B, 6D). Scapus dorsally black, otherwise brown (Figs. 6A, 6D); basal antennal segments black, thereafter brown with some segments black (Figs. 6A, 6D). Frons and mouthparts dark coloured (Fig. 6C). Maxillary and labial palps yellow brown (Figs. 6B, 6C). Lateral parts of head, including genae, light brown; with a black horizontal band behind eyes. Pronotal dorsal disc brown, apical margin with white scales. Pronotal lateral lobes also with white scales and with brown margins (Fig. 6D). Tegmen mostly infumated white, but infumated grey at apical area of lateral field (Fig. 6D). Femur generally pale brown to brown. Fore and middle tibiae dorsally black, otherwise brown. Tarsi with basal segment brown, with middle and apical segments black. Hind femur generally brown with knee dark. Hind tibia brown, dorsally pale yellow. Abdomen with tergites black covered with greyish brown scales; sternites black with whitish scales especially on those nearer to thorax. Abdominal apex black; last abdominal tergite back with brown setae along posterior margin (Fig. 6E). Cercus brown.

Measurements (in mm). Holotype BL = 7.6; FRW = 0.28; SW = 0.22; EW = 0.26; PL = 3.9; PW = 2.2; TL = 2.3; HFL = 4.3; HFW = 1.3; HTL = 4.0; HML = 0.9.

Distribution. Borneo (Brunei Darussalam)