Ceresium unicolor (Fabricius, 1787)

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 : 40

Taxon classification Animalia Coleoptera Cerambycidae

Ceresium unicolor (Fabricius, 1787) Fig. 17

Saperda unicolor : Fabricius 1787: 147, Amsterdam Island, French Southern Islands, holotype (BMNH).

Description.

Based on the original description (Fabricius 1787) and specimens from 1938, 2005 and 2007 surveys (FNIC, USP). Size 15.0-17.0 mm long, 3.0-4.0 mm wide at humeri; integument color orangish-brown to maroon-brown (occasionally piceous) (Fig. 17a). Head with shallow interantennal tubercle region, tubercles only slightly raised; punctate with moderately dense yellow pubescence on tubercles; vertex and occiput with sparser yellow pubescence. Yellow pubescence denser around eye margins. Frons and frontoclypeal margin densely, coarsely punctate with sparse, long, yellow hairs (Fig. 17b). Antennae long, extending beyond elytra by 1-2 antennomeres. Antennae with vestiture of short, dense, ochraceous setae (longer at apices of antennomeres). Antennomeres unspined and slightly expanded at apices; last antennomere subequal in length of penultimate. Antennomere 3 and 4 each shorter than scape; 3 shortest; 5-9 longest and subequal in length. Scape long, clavate, extending to apical sixth of pronotum.

Pronotum broadly arcuate quadrate, widest across middle, and as long as wide. Tubercles absent. Pronotum with a broad median line and a fine line slightly half-way between middle and sides on each side of pronotum. Pronotum with moderately dense to dense yellow pubescence. Pronotum with sparse, coarse punctures (Fig. 17c). Elytron with sparse and evenly spaced yellow pubescence throughout. Punctation shallow, sparse, gradually becoming shallower and smaller in size towards apex. Elytral apex rounded to suture. Scutellum broadly rounded, covered with dense, yellow pubescence. Legs moderate in length, femora distinctly but gradually clavate, hind femora reaching base of fourth ventrite.

Venter of abdomen and metasternum with sparse yellow pubescence towards center and becoming denser on sides. Prosternal process moderately narrow, vertical and acutely declivous, about 1/4 width of procoxa, weakly notched and not expanded at apex. Procoxal cavities open posteriorly (Fig. 17d). Mesocoxae closed laterally to mesepimeron. Mesosternum rather acutely declivous, with small anterior tubercle, and sulcate anteriorly. Mesosternal process expanded at base into tubular tooth inserted into mesocoxa. Apex of terminal ventrite truncate with a slight bump towards middle.

Remarks.

This species is somewhat variable and lacking a suite of very distinctive characters. In the key, it is distinguished by the pronotum lacking maculae and lateral tubercles but having several dorsal calli, and having pubescence of the head, pronotum, elytra and scutellum similar in density and coloration. This species is widespread and known from Mauritius, Seychelles, New Zealand, Waigeo Island, Papua New Guinea, Bismarck Archipelago, Solomon Islands, Vanuatu, Hawaii, and Fiji ( Bigger and Schofield 1983). In Fiji, it is known known from Viti Levu, Taveuni, Lau Islands, and Vanua Levu where specimens have been collected throughout the year, most commonly at lights ( Dillon and Dillon 1952).