Taxonomic history

Xyleborus improcerus Sampson, 1921: 33.

Xylosandrus improcerus (Sampson): Beaver, 1998: 183.

Cnestus improcerus (Sampson): Dole and Cognato, 2010: 529.


2.7−3.3 mm long (mean = 3.04 mm; n = 5); 1.67−1.74 times as long as wide. This species can be distinguished by the presence of a mesonotal mycangial tuft on the pronotal base; elytral disc very short; procoxae widely separated; elytral declivity bicolored, with the basal half black and the apical half with a pale translucent area; declivity flat; pronotum type 1 when viewed dorsally; antennal club type 2, with two sutures visible on posterior face; antennal funicle four-segmented; protibia distinctly triangular; posterolateral margin of elytra moderately carinate from apex to declivital base along interstriae 7; interstriae punctate, setose, and ground vestiture absent.

May be confused with

Xylosandrus spp., Cnestus gravidus, C. mutilatus, and C. testudo


‘Borneo’, Brunei, East & West Malaysia, Thailand

Host plants

recorded from Canarium (Burseraceae), Dipterocarpus (Dipterocarpaceae), and an unidentified genus of Lauraceae (Browne 1961b)


Reported by Wood and Bright (1992) as occurring in India but no actual records have been found.

DNA data

Sequences available for COI and CAD.

COI: GU808715

CAD: GU808636