Ceresium decorum Dillon & Dillon, 1952

Waqa-Sakiti, Hilda, Winder, Linton & Lingafelter, Steven W., 2015, Review of the genus Ceresium Newman, 1842 (Coleoptera, Cerambycidae) in Fiji, ZooKeys 532, pp. 15-53 : 19

Taxon classification Animalia Coleoptera Cerambycidae

Ceresium decorum Dillon & Dillon, 1952 Fig. 2

Ceresium decorum : Dillon and Dillon 1952: 22, Fiji: Moala, Vanuka, holotype (BPBM).

Redescription.

Based on the holotype specimen (BPBM) and original description. Size 11.7 mm long, 2.8 mm wide at humeri; integument color brown (paler towards elytral apex; Fig. 2a). Head with shallow interantennal tubercle region, tubercles only slightly raised; punctate with very sparse ochraceous pubescence on tubercles and throughout frons; vertex and occiput with sparser ochraceous pubescence. Ochraceous pubescence less dense around eye margins. Frons and frontoclypeal margin punctate with sparse, short and long, ochraceous hairs (see head details on Figure 2b). Antennae long, extending beyond elytra by three antennomeres. Antennae with vestiture of short, moderately dense, ochraceous setae (longer at apices of antennomeres). Antennomeres unspined and not expanded at apices; Antennomeres 9-11 were damaged. Antennomere 3 and 4 each longer than scape; 5 longest. Very short scape, wide, extending just slightly beyond pronotal front.

Pronotum broadly arcuate, widest across middle, and almost as wide as long. Pronotum with glabrous median vertical line, glabrous patch on either basal sides of median line. Pronotum with sparse punctures and sparsely scattered pubescence elsewhere (Fig. 2c). Elytron with sparse and regularly spaced ochraceous pubescence. Punctation dense, shallow and gradually becoming shallower and smaller in size towards apex. Elytral apex rounded to suture. Scutellum triangular, narrowly rounded, covered with sparse, ochraceous pubescence. Legs moderate in length, femora distinctly but gradually clavate, length of hind femora (3.64 mm), base of femur extending to apical margin of 5th ventrite.

Venter of abdomen and thorax with sparse translucent to pale, ochraceous pubescence throughout. Length of abdomen 4.38 mm. Prosternal process very narrow, gradually declivous, weakly notched and expanded at apex, approximately 1/8 width of procoxa. Procoxal cavities widely open posteriorly. Mesocoxae closed laterally to mesepimeron. Mesosternum not produced vertically, without anterior tubercle or sulcus; with weak but acute lateral projections into mesocoxae (Fig. 2d). Apex of terminal ventrite subtruncate without notch.

Remarks.

This species is most similar to Ceresium promissum Dillon & Dillon based on the key characters. It is distinguished from that species by having the mesosternal process basal notch angled (parallel-sided in Ceresium promissum ) and the pronotum having a narrow, glabrous, longitudinal line centrally located (restricted to posterior half in Ceresium promissum ). This species is endemic to Fiji and known only from Moala, Viti Levu, and Lau Islands. It has been collected from rotten logs and dead branches in August and October ( Dillon and Dillon 1952).