Truncaudum agnatum (Eggers) Eggers, 2010

Hulcr, Jiri, 2010, New genera of Palaeotropical Xyleborini (Coleoptera: Curculionidae: Scolytinae) based on congruence between morphological and molecular characters, Zootaxa 2717, pp. 1-33 : 25-26

Truncaudum agnatum (Eggers) , comb. n.

Xyleborus agnatus Eggers, 1923

Cyclorhipidion agnatum (Eggers) : Wood and Bright, 1992 Xyleborus delicatus Schedl, 1955 syn. n.

Cyclorhipidion delicatum (Schedl) : Wood and Bright, 1992 syn. n. Cyclorhipidion subagnatum Wood, 1992 syn. n.

Xyleborus gratiosus Schedl (1975b) syn. n.

(complete taxonomic history in Wood and Bright, 1992, Bright and Skidmore, 1997) Specimens examined. T. agnatum : Malaysia, Sarawak (unspecified " type ", MCG); New Guinea, Hatam (co-type, MCG); Malaysia, Sabah, Danum Valley (4, Hulcr det., MSUC); New Guinea (1, Hulcr det., FICB); New Guinea, Western Province, Wavoi (1, Hulcr det., FICB); New Guinea, Madang Prov. (111 indiv.), Oro Prov. (5), West Sepik (33) (Hulcr det., MSUC). C. delicatum : New Guinea (holotype, NHMW). C. subagnatum : Philippines, Tumigan(?) (lectotype, NHMW); New Guinea, West New Britain (1, Hulcr det., FICB); New Guinea, Morobe Province, Bulolo (1, Hulcr det., MSUC); Philippines, Luzon, Tayabas (6 Hulcr det., SMTD). X. gratiosus : New Guinea (holotype, NHMW).

Comments. T. agnatum is the only Truncaudum without sharply truncated declivity. However, all other characters and a molecular phylogeny place this species within Truncaudum ( Fig. 8 , Cognato et al., 2011). It is extremely variable in body size (2.0-3.0 mm) and elytral declivity (from obliquely rounded to nearly truncated). Very similar to Cyclorhipidion californicum and C. pelliculosum , but not closely related ( Cognato et al., 2011). T. agnatum differs by the more flatten declivity surrounded by conspicuous tubercles and the antennae type 2 (first segment covering most of posterior side), rather than 3 (not obliquely truncated, segments 2 and 3 clearly visible on both sided).

C. delicatum and C. subagnatum differ from T. agnatum in the slightly different size of several declivital tubercles, but not by any phylogenetically significant character. T. agnatum is almost identical to X. gratiosus , except the declivity appears superficially different. Strial punctures on the declivity of the X. gratiosus holotype (the only specimen known to us) are enlarged, and their inner surface is shagreened, which results in much more rugged appearance of the whole declivity.

Figures

FIGURE 8. A morphology-based cladistic analysis of species previously placed in Amasa, Cyclorhipidion, Xyleborus, and similar species of unclear affiliation. Combinable-component consensus of 240 most parsimonious trees (60 steps). The large number of MP trees is almost entirely due to the lack of resolution among the terminal Amasa spp., illustrating the paucity of synapomorphic characters in these dubious species. Numbers at nodes indicate Bremer support.