Planiculus bicolor (Blandford), comb. n.

Xyleborus bicolor Blandford, 1894

Euwallacea bicolor (Blandford): Wood and Bright 1992 Xyleborus filiformis Schedl, 1975b syn. n.

Euwallacea filiformis (Schedl): Wood and Bright, 1992 syn. n. Xyleborus laevis Eggers, 1923 syn. n.

Euwallacea laevis (Eggers): Wood and Bright, 1992 syn. n. Xyleborus tumidus Schedl, 1975b, syn. n.

Euwallacea tumidus (Schedl): Wood and Bright, 1992, syn. n. Xyleborus glabratulus Browne, 1983 syn. n.

(complete taxonomic history in Wood and Bright, 1992)

Specimens examined. P. b i c o l o r: Japan, Nagasaki (syntypes, BMNH); Fiji, Namosi (Xyleborus rameus Schedl det., syn. of P. b i c o l o r, BMNH); Indonesia, Sulawesi (1, Hulcr det., BMNH); Malaysia, Sabah, Danum Valley (2, Hulcr det., MSUC); New Guinea, New Britain (1, Hulcr det., FICB); New Guinea, Milne Bay, Mt. Dayman (1, Hulcr det., NHMW); Thailand, Pong Yaeng N. P. (2, R. A. Beaver det., MSUC); New Guinea, Madang Prov. (170, Hulcr det., MSUC), Oro Prov. (176, Hulcr det., MSUC), West Sepik (51, Hulcr det., MSUC). E. filiformis: New Guinea, Morobe Province, Bulolo (holotype, NHMW); New Guinea, Morobe Province, Bulolo (1, Hulcr det., FICB); New Guinea, Morobe Province, Bulolo (1, Hulcr det., NHMW). E. laevis: Indonesia, Java (lectotype, USNM); Philippines, Luzon (SMTD). E. tumidus: New Guinea, Morobe Province, Bulolo (holotype, NHMW). X. glabratulus: New Guinea, Solomon Islands, Viru Harbour, imported to Japan (Nagoya) (holotype, BMNH).

Comments. This species is distinguished from other Planiculus spp. by the rounded apex of elytra, and gently sloped declivity. The pattern of declivital granules is extremely variable, usually there are several larger tubercles on interstriae 1 and 3, and 0 or only very small granules on interstriae 2.

Planiculus bicolor, Euwallacea laevis, E. artelaevis, and E. tumidus are often confused and misidentified. Their type specimens are virtually identical, except body size and declivital sculpture varies among different regions or islands (Browne, 1966). The three known specimens of E. filiformis are slightly elongated P. b ic o lo r. They were collected at the same locality within two years, likely representing a local deviation of body shape. The separate position of E. filiformis holotype in our morphological phylogeny (Fig. 9) is due to the effect of missing values for inaccessible ventral characters. The holotype of X. glabratulus fits the variation within P. b i c o l o r. It differs only by its slightly more granulated and setose declivity, and slightly more prominent posterolateral declivital costa.