Diuncus justus (Schedl, 1931) Fig. 50C, D, J

Xyleborus justus Schedl, 1931: 339.

Diuncus justus (Schedl): Hulcr and Cognato 2009: 32.

Xyleborus marginicollis Schedl, 1936c: 64. Synonymy: Hulcr 2010: 107.

Xyleborus ciliatus Eggers, 1940: 141. Synonymy: Hulcr and Cognato 2013: 81.

Xyleborus apiculatus Schedl, 1942a: 190. Synonymy: Hulcr and Cognato 2013: 81.

Type material.

Holotype Xyleborus justus (NMNH). Holotype Xyleborus marginicollis (NHMW).

New records.

Vietnam: Cao Bang, 22°34.5'N, 105°52.4'E, ~ 1080 m, 14.iv.2014, VN28, Cognato, Smith, Pham, ex Cunninghamia branches (MSUC, 1).

Diagnosis.

1.5-1.7 mm long (mean = 1.65 mm; n = 5); 2.36-2.5 × as long as wide. This species is distinguished by the minute size; unarmed declivity; declivital striae 1 shallowly impressed; nearly glabrous appearance; and lateral margin of the protibiae armed with four denticles.

Similar species.

Diuncus ciliatoformis .

Distribution.

Australia, China (Fujian), Indonesia (Java), East & West Malaysia, New Guinea, Vietnam*.

Host plants.

This species has only been recorded from Cunninghamia ( Cupressaceae).

Remarks.

The synonymy of Xyleborus apiculatus, X. ciliatus, and X. marginicollis with Diuncus justus needs to be reassessed using information from DNA as well as morphology.