Debus fallax (Eichhoff), comb. n.

Xyleborus fallax Eichhoff (1878)

Xyleborus fastigatus Schedl (1935) syn. n.

(complete taxonomic history in Wood and Bright, 1992)

Specimens examined. Malaysia, Sabah, Danum Valley (51, Hulcr det., MSUC); New Guinea, Morobe Province, Bulolo (1, BHJ); New Guinea (5, Hulcr det. BBM); New Guinea, Morobe Province, Bulolo (1 Hulcr det., MSUC); Philippines, Luzon, Mt. Makiling (holotype of X. amphicranulus Eggers., syn. of X. fallax, SMTD); Sulawesi (1, BMNH); Thailand, Pong Yaeng N. P. (2, Hulcr det., MSUC), New Guinea, Madang Prov. (36, Hulcr det., MSUC), Oro Prov. (66, Hulcr det., MSUC), West Sepik (123, Hulcr det., MSUC); X. fastigatus: Philippines, label: Sch. of For., Univ. P.I. (lectotype, NHMW).

Comments. Placement of D. fallax in the Debus clade was confirmed by a molecular phylogenetic analysis (100% posterior probability, Cognato et al., 2011). Depository of the holotype is unclear. Wood and Bright (1992) indicated IRSNB as the depository, but the museum personnel reported that the holotype was never deposited there. Schedl (1954a) discussed the large variation in overall shape, in the relative sizes of the declivital teeth, and in the declivital emargination. In particular, the position and size of the second tooth varies widely, with no obvious relation to biogeographical regions. Lectotype of X. fastigatus falls within the variation of X. fallax .

Distribution. This species is probably the most common and widespread of all Debus spp. (Browne 1961), with large regional morphological variation.