Ceresium gibbicolle, Yokoi, 2019

Ceresium gibbicolle View in CoL sp. nov.

Figs 9A- C View Fig , 21A- I

Types. Holotype Ƌ: “N-Sumatra, Pema tang-Siantar, Diehl leg., 85” ( ZSM).

Diagnosis. Colour analogous to C. zeylanicum , C. humerale Schwarzer, 1931 or C. aemulator . Smaller and slenderer. Pronotum longer; sub-conical; raised distinctly in apical half; less punctate and less setose. Elytra more sparsely punctured. Legs more strongly clavate.

Etymology. The name of this species refers to the elevations on the pronotum.

Description

Measurements. TL = 8.4 mm; EL/EW= 3.12; HW/ PW= 1.06; PL/PW = 1.20; PA/PW = 0.80; PB/PW =1.04.

Colour. Similar to the above-mentioned species. Elytra darker near sides and toward apices.

Head. Analogous to that of C. humerale ; though wider than pronotum and less setose. Vertex wider, less concave. Scape 1.23 × longer than 3 rd antennal article.

Pronotum as in Figure 9B View Fig ; long and sub-conical. Sides tapering weakly and linearly toward apex; constricted there; each provided with three small glossy elevations; thickly clothed with pale, curly, adpressed hairs otherwise. Base clothed similarly as sides. Disc strongly elevated in apical half forming a pair of glabrous, oblique and oval humps ( Fig. 9C View Fig ); provided sparsely with shallow, medium-sized setiferous punctures around the elevations and median stripe, with the belonging pale setae short and adpressed. Median stripe in basal half broad, flattened and triangular in shape, naked and shiny. Scutellum as of C. zeylanicum .

Elytra. Long and slender; moderately narrowed toward apex. Setiferous punctures less dense than those of comparable species.

Legs. Femora more sharply clavate with longer peduncles than those of comparable species.

Venter. Prosternum a little raised in middle; provided with several large and deep punctures near middle and smaller ones near sides; thickly clothed with pale, short, adpressed hairs near sides. Prosternal process narrow, truncated on apex. Mesosternum concave in apical middle; hardly punctured; setae as on prosternum, though sides even more thickly furnished with pale hairs. Mesosternal process flat and broad; with apex produced and deeply emarginated in U-form. Metasternum naked and shiny in middle; thickly clothed with pale recumbent hairs of medium length otherwise.

Abdomen. Sides moderately clothed with pale hairs as metasternum.5 th visible sternite rather short, narrowed apicad, with apex very widely emarginated in the middle.

Genital organs as in Figure 21A- I. Median lobe half the length of abdomen; bullet-shaped in dorsal view, though a little emarginated in basal half; arcuate in profile; dorsal plate declivous on sides, dehiscent in basal half; ventral plate distinctly longer than dorsal plate, dehiscent in basal 3 / 4. Median struts narrow though apicad dilated. Tegmen almost 6 / 7 the length of median lobe. Parameres about 2 / 5 the length of tegmen; dehiscent in apical 1 / 5; with each lobe tapering gradually in sub-linear line toward apex, which is rounded and furnished with long setae; arcuate and rather thick in profile. Ejaculatory duct complex as in Figure 21F- H; stout and thick in profile; apical sclerite moderately sclerotized, with a broad and thin projection on apex, produced at the latero-apical corners. 8 th sternite strongly arcuate on sides; apex emarginated in V-form; clothed with medium-sized setae on apex and sparse short hairs near middle. 8 th tergite as wide as the corresponding sternite; bell-shaped with apex moderately pointed; clothed with long hairs on apex.

Distribution. North Sumatra.

Comparative notes. This new species resembles C. zeylanicum or C. aemulator regarding colouration, C. humerale regarding antennal structure. Its pronotum is, however, distinct. It is sub-conical in outline with almost straight sides, much less punctured and setose, with its apical elevations more prominent. Further, its elytra are more sparsely punctured and femora more sharply clavate.In addition, it is smaller.

Remarks. Holotype was found in a group of specimens with a label “ Examnes undet.” in “Hüdepohl Collection” (ZSM).