Taxonomic history

Xyleborus attenuatus Blandford, 1894b: 114.

Xyleborinus attenuatus (Blandford): Beaver and Liu, 2010: 30.

Synonyms

Xyleborus alni Niisima, 1909: 160. Knížek, 2011: 246.

Xyleborus canus Niisima, 1909: 161. Smith et al., 2018b: 397.

Diagnosis

2.6−2.9 mm long (mean = 2.78 mm; n = 5); 2.9−3.25 times as long as wide. This species is distinguished by the declivital face with interstriae 2 armed by granules at declivital summit, unarmed on declivital face; denticles of declivital interstriae 3 larger than those of interstriae 1; denticles pointed, spine-like, slightly incurved; denticles on interstriae 5 large, sharply pointed, spine-like, curved slightly downwards; discal interstriae 1 and 2 unarmed; de­clivital interstriae 2 flattened; and large size.

This species is nearly identical to Xyleborinus n. sp. 4 and can be distinguished by the declivital interstriae 3 denticles that are incurved rather than acutely pointed and interstriae 5 denticles always down-curved.

May be confused with

Xyleborinus saxesenii, X. subgranulatus, X. subspinosus, and X. thaiphami

Distribution

China (Chongqing, Shaanxi), Japan, Korea, Russia (Far East), Taiwan; introduced and established in Central and Northern Europe and North America (Knížek 1988, Hoebeke and Rabaglia 2007, Gomez et al. 2018a)

Host plants

recorded from trees in the families Betulaceae, Fagaceae and Rosaceae (Beaver and Liu 2010) and Pinus (Pinaceae) (Smith et al. 2020b)

DNA data

specimens not available for sequencing