Ceresium holzschuhi, Yokoi, 2023

Yokoi, Yaheita, 2023, Note on genitalia and taxonomy of the Callidiopini from the Philippines, with description of six new species and two subspecies (Coleoptera, Cerambycidae, Cerambycinae), Contributions to Entomology 73 (1), pp. 31-66 : 31

Ceresium holzschuhi sp. nov.

Figs 3A-F , 18A-K

Type material.

Holotype ♂ (SMF): "Philippines, 1600m;" "Mindanao, 30Km W. of Marang," "28. - 30. Dec. 1990," "Rolm lgt," "Coll. Lgt. C. Holzschuh 2015," (former CCH).

Etymology.

The name of this species is dedicated to Mr. Carolus Holzschuh of Villach, Austria. The holotype belonged to his private collection.

Diagnosis.

Slender. Colour fulvus to testaceous. Elytra elongated, apically tapering. Punctures on pronotal disc deep and regular. Apical middle of 8th sternite elevated, distinctly setose.

Measurements.

Holotype ♂: TL = 10.5 mm; EL/TL = 0.70; EL/EW = 3.25; HW/PW = 0.93; PL/PW = 1.12; PA/PW = 0.74; PB/PW = 0.94.

Description.

Colour fulvus; thorax and head testaceous; abdomen reddish dark yellow; setae pale yellowish to whitish.

Head narrower than pronotum; glossy; punctures dense and regular; setae dense, stout, curved, recumbent; median furrow stretching from frons to vertex. Frons transverse, rather flattened, not steep; apex as broad as base; sides moderately emarginated. Vertex moderately concave. Occiput finely sub-rugose. Eyes separated from one another by half the width of occiput or 11/5 that of the upper eye-lobes. Antennal supports flattened; each sub-encircled by an arcuate row of diminutive setiferous punctures. Antennae surpassing the pronotal base at antennomere IV. Length of antennomeres relative to scape: III = 0.95; IV = 0.9; V = 1.25; VI = 1.25. Scape sub-arcuate and strongly clavate. Remark: Antennae damaged; antennomeres VII-XI missing.

Pronotum (Fig. 3C ) longer than broad; apex narrower than base. Setae sparse, fine on disc; dense, adpressed on both sides of disc; additional several longer erect setae on sides. Punctures on disc regular, large, deep; median stripe short. Sides moderately arcuate, weakly constricted near basal 1/5; surface uneven with irregular elevations; punctures on sides dense, deep and coarse.

Scutellum bell-shaped; with dense pubescence.

Elytra elongated, sides distinctly tapering toward apices; apices separately rounded; punctures deep, regular, setiferous; setae curved and adpressed.

Legs slender, femora clavate from base.

Venter (Fig. 3B, D ): Prosternum convex, rounded; punctures large, deep, regular, setiferous; setae curved, recumbent, pointing to the direction of the process. Prosternal process narrow, constricted; apex truncated. Mesoventrite saddle-shaped; moderately elevated toward the process; punctures sparse and shallow; setae short and fine. Mesoventral process broad, flattened; punctures obtuse; setae sparse; sides emarginated; apex bi-lobed with sub-W-formed apical margin. Metaventrite glossy, apically slightly dilated, impressed along the median furrow; punctures on both sides of the impression obtuse. Abdomen glossy, nearly impunctate; setae in the middle sparse, medium to short, curved, recumbent; setae near sides denser; 7th sternite trapezoidal; apex truncated.

Male genitalia (Figs 3E, F , 18A-K ): Median lobe about 1/3 the length of abdomen; fusiform in dorsal view; slender and arcuate in lateral view; dorsal plate dehiscent in basal 3/5; ventral plate similarly long, dehiscent in basal 4/5, apically narrowed, with sub-acute apex. Tegmen nearly 3/4 as long as median lobe; moderately arcuate in lateral view. Parameres about 9/20 the length of tegmen; apical 1/5 bi-lobed; lobes broad, each fringed with a few long and several short apical setae. Apical process of endophallus as Figs 3F , 18D-F ; less than 3/10 the length of median lobe; sub-monolithic; the middle thick in lateral view, with a prominent, horn-shaped dorso-apical projection; base spatulate, thick; both sides projected downward, loosely connected to a 4-armed, curved-spatulate apical appendage. Blade of 8th sternite as Figs 3E , 18J-K : transverse; apex shallowly emarginated in a bi-sinuate line; apical middle distinctly elevated, clothed with a cluster of long, erect, well-aligned setae stretching forward; hairs on and near sides aligned, pointing to the elevated middle; peduncle shorter than blade. 8th tergite sub-linguate; apex and sides fringed with setae of various lengths.

Distribution.

Mindanao, Philippines.

Comparative notes.

This new species can be compared to Ceresium virens Heller, 1914, from Papua New Guinea. Both species are similar in body structure, in particular regarding their characteristic elongated, tapering elytra. The new species can be easily distinguished by the surface of pronotum and elytra: the punctures are regular and deep, whereas they are irregularly aligned and of varying depth in C. virens . In addition, the legs and antennae of the latter are longer and more slender. The new species shares also a few external characteristics with the above described C. elongatipenne sp. nov. Meso-and metathorax, abdomen and legs are essentially similar. In contrast, they obviously differ from each other by the structure and surface of the prothorax. The distinctions in genitalia are even more evident. The endophallus, apical process in particular, of C. holzschuhi is rather reminiscent of Ceresium sugiartoi Yokoi, Makihara & Noerdjito, 2019, or to those of Examnes species (See Discussion). The elevation in the apical middle of its 8th sternite with a cluster of aligned, erect setae thereupon is remarkable, a new observation in the genus.

Figures

Figure 3. A-F. Ceresium holzschuhi sp. nov. Holotype male. A. Habitus, dorsal view; B. Ditto, ventral; C. Head and pronotum; D. Prosternum and mesoventrite; E. 8 th sternite with 8 th tergite in the background, latero-ventral view; F. Median lobe and endophallus with apical process.

Figure 18. A-K. Ceresium holzschuhi sp. nov. Holotype male. Genitalia. A. Median lobe with endophallus, dorsal view; B. Ditto, lateral; C. Ditto, ventral; D. Endophallus, apical process, dorsal view; E. Ditto, lateral; F. Ditto, ventral; G. Tegmen, dorsal view; H. Ditto, lateral; I. Ditto, ventral; J. 8 th sternite and tergite, ventral view; K. Ditto, fronto-lateral view. Scale bars: 0.2 mm (D-F); 1 mm (A-C, G-K).