Ceresium elongatipenne, 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 elongatipenne sp. nov.

Figs 1A-I , 2A, B , 17A-L , 28A, B

Type material.

Holotype ♂ (SMF): "Imagun, Luzon "; "Senckenberg Museum, Frankfurt".

Paratype ♀ (SMF): ditto.

Etymology.

The name of this species refers to its elongated elytra.

Diagnosis.

Slender. Colour testaceous. Elytra parallel-sided, distinctly elongated. Pronotal disc densely punctured. Blade of 8th sternite extremely short. 8th tergite strongly elongated.

Measurements.

Holotype ♂: TL = 10.8 mm; EL/TL = 0.73; EL/EW = 3.27; HW/PW = 0.97; PL/PW = 1.06; PA/PW = 0.73; PB/PW = 0.88. Paratype ♀: TL = 10.8 mm; EL/TL = 0.74; EL/EW = 3.30; HW/PW = 1.0; PL/PW = 1.06; PA/PW = 0.76; PB/PW = 0.92.

Description of holotype male.

Colour universally testaceous, thorax slightly darker; setae pale yellowish to whitish.

Head nearly as broad as pronotum, glossy; punctures dense and regular; setae stout, curved, disorderly, pointing in different directions; median furrow from frons to occiput. Frons longer than broad; rather flattened; not steep; apex nearly as broad as base; sides moderately emarginated. Vertex moderately concave. Occiput finely sub-rugose. Eyes separated from one another by 5/9 the width of occiput or 3/2 that of the upper eye-lobes. Antennal supports broad, flattened, impunctate, each sub-encircled by an arcuate row of diminutive setiferous punctures. Antennae reaching elytral apices at antennomere X. Length of antennomeres relative to scape: III = 1.0; IV = 0.95; V = 1.4; VI = 1.25; VII = 1.25; VIII = 1.15; IX = 1.04; X = 0.95; XI = 1.05. Scapes sub-arcuate and strongly clavate.

Pronotum (Fig. 1C ) shiny, a little longer than broad; broadest at apical 1/3; apex narrower than base; punctures dense and regular; setae around the disc stout, curved, sub-erect, mostly pointing to the middle; setae on disc finer. Disc bordered by an irregular, glabrous costa on each side; median stripe broad. Sides evenly arcuate on apical 3/4, constricted at basal 1/4; surface uneven with irregular elevations; each with several additional longer erect setae.

Scutellum sub-circular; fringed by diminutive setae.

Elytra elongated in relation to the body; sub-parallel-sided; apices separately rounded; punctures regular, dense, setiferous; setae on disc finer than the others.

Legs rather slender; femora clavate from base.

Venter (Fig. 1B, D ): Setae in middle sparse, short, curved, disorderly; denser, longer, recumbent and aligned towards sides. Prosternum convex, rounded; the middle with micro-punctures or finely rugose; with several large punctures near each latero-apical corner. Prosternal process narrow, constricted; apex truncated. Mesoventrite saddle-shaped; moderately elevated toward the process; the middle finely punctured. Mesoventral process broad, flattened, sparsely setose; sides deeply emarginated; apex bi-lobed with sub-W-formed apical margin. Metaventrite glossy; apically slightly dilated; impressed along the median furrow; regularly punctured on both sides of the impression. Abdomen glossy; punctures sparse and fine; sternites 3-5 widely hairless in middle; 6-7 sparsely setose; 7th sternite as long as the preceding; apex arcuate. 7th tergite well rounded; the apical margin fringed with long setae (Fig. 17L ). Male genitalia (Figs 1E-I , 17A-L ): Median lobe about 3/8 the length of abdomen; elongated-bullet-shaped in dorsal view; moderately arcuate in lateral view; dorsal plate dehiscent in basal 2/3; ventral plate similarly long, dehiscent in basal 7/8, with apex strongly narrowed and produced (Fig. 17C ). Tegmen more than 9/10 as long as median lobe; narrow in dorsal view; moderately bi-sinuate in lateral view. Parameres nearly half the length of tegmen; apical 3/10 bi-lobed; lobes each clothed with short to long apical setae. Apical process of endophallus (Figs 1I , 17D-F ) about 3/10 as long as median lobe; apical sclerite triangularly projected in dorsal view; thick, curved downward in lateral view; median sclerite with a prominent, horn-shaped ventro-basal projection and a smaller, thinner dorso-apical projection; both lateral sclerites posteriorly extended in the shape of median struts of median lobe. Blade of 8th sternite short, sub-cotyledonary; apex doubly deeply emarginated; base deeply emarginated on each side of the middle; apex and sides fringed with medium to short hairs; peduncle a little longer than blade. 8th tergite elongated-bell-shaped, exceptionally large and long, fringed with medium to short setae; additional setae near sides and apex shorter.

Description of the female paratype (Sexual dimorphism).

Antennae reaching elytral apices at the middle of antennomere XI. Abdomen more voluminous than in male.

Female genitalia (Figs 2B , 28A, B ): 8th sternite weakly dilated towards apex; peduncle more than three times as long as blade. 8th tergite sub-squarish; latero-basal corners acute; both sternite and tergite fringed with several long apical setae. 9th sternite slender; coxite more than 3/5 as long as paraproct; styli each furnished with a few setae. Vaginal plates short. Bursa copulatrix oval; connected to the apical vagina by a long tube. Spermatheca kidney-shaped, connected to apical vagina by a long winding duct.

Distribution.

Luzon, Philippines.

Comparative notes.

This new species can be distinguished from all congeneric species by the parallel-sided, strongly elongated elytra. They are not only proportionally elongated in themselves, but also in relation to body, with EL/TL = 0.73-0.74. As to male genitalia, the structures of its 8th sternite and tergite are, as above described, exceptional in Ceresium . Apical process of its endophallus is elaborate and characteristic of the species.

Figures

Figure 1. A-I. Ceresium elongatipenne sp. nov. Holotype male. A. Habitus, dorsal view; B. Ditto, ventral; C. Pronotum; D. Prosternum and mesoventrite; E. 8 th sternite, ventral view; F. 7 th sternite and 8 th tergite, ventral view; G. 8 th sternite and tergite, ventral view; H. Median lobe and endophallus, lateral view; I. Apical process of endophallus, dorsal view.

Figure 2. A, B. Ceresium elongatipenne sp. nov. Paratype female. A. Habitus, dorsal view; B. Genitalia, from top: 8 th sternite; 9 th sternite (part); vagina with vaginal plates; bottom from left: spermatheca; bursa copulatrix; median oviduct.

Figure 17. A-L. Ceresium elongatipenne 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, ventral view; K. Ditto, with 8 th tergite in the background; L. 7 th and 8 th tergite, dorsal view. Scale bars: 0.5 mm (D-F); 1 mm (A-C, G-L).

Figures 28 - 30. 28 A, B. Ceresium elongatipenne sp. nov. Paratype female. 28 A. 8 th sternite, ventral view; 28 B. 8 th tergite, dorsal view. 29 A, B. Ceresium quinquemaculatum sp. nov. Holotype female. 29 A. 8 th sternite, ventral view; 29 B. 8 th tergite, dorsal view. 30 A-C. Ceresium striatocolle Holzschuh. Female from Borneo. 30 A. 8 th sternite, ventral view; 30 B. 8 th tergite, dorsal view; 30 C. Spermatheca. Scale bars: 1 mm (28 A, B; 29 A, B; 30 A-C).