Described from Koné in 1903 under the name of Acupalpus trapezus.

Placed today in the genus Lecanomerus.

"Body length 4.1- 5.0 mm ; width 1.6-2.0 mm.

Shiny. Head blackish brown with labrum and mandibles (inner margin and apex darker) reddish, palpi pale yellowish brown. Pronotum dark brown with lateral margins, base and sometimes also apex paler reddish brown. Elytra dark brown or blackish brown, with first, seventh and eights interval and apex yellowish. Usually also the apical parts of interval 2, 3, 4 and 6 yellowish. Antennae yellowish or pale reddish brown, sometimes antennomeres 1-4 partly infuscated. "

Bernd JAEGER "Two new species of the Anthracus annamensis group from Australia and New Caledonia, and notes on identity and generic placement of Acupalpus angulatus MACLEAY, 1871 and Acupalpus trapezus FAUVEL, 1882 (Coleoptera, Carabidae, Harpalini, Stenolophina, Pelmatellina)" 2016.