A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China Author Smith, Sarah M. Department of Entomology, Michigan State University, 288 Farm Lane, East Lansing, Michigan 48824, USA https://orcid.org/0000-0002-5173-3736 camptocerus@gmail.com Author Beaver, Roger A. 161 / 2 Mu 5, Soi Wat Pranon, T. Donkaew, A. Maerim, Chiangmai 50180, Thailand Author Cognato, Anthony I. Department of Entomology, Michigan State University, 288 Farm Lane, East Lansing, Michigan 48824, USA text ZooKeys 2020 983 1 442 http://dx.doi.org/10.3897/zookeys.983.52630 journal article http://dx.doi.org/10.3897/zookeys.983.52630 1313-2970-983-1 7DED4CE2934C4539945F758930C927F9 C890C7FD4B2D57A8B1A062305ED42D53 Diuncus mucronatus (Eggers, 1923) Fig. 50G, H, L Xyleborus mucronatus Eggers, 1923: 191. Diuncus mucronatus (Eggers): Hulcr and Cognato 2009 : 34. Type material. The holotype was destroyed in the bombing of UHZM in World War II ( Wood and Bright 1992 ). New records. China: Guizhou, Guiyang, Huaxi, 25.x.2015, Y. Li, ex trap baited with ipsenol + EtOH (MSUC, 1). Hong Kong, Tai Po Kau, vi.2017, J. Skelton (MSUC, 4). Jiangsu, Nanjing, Laoshan National Park, Bacai Road, 32.09156N , 118.583701E , 15.viii.2017, Cognato, Li, Gao, ex Populus (MSUC, 2). Vietnam: Cao Bang, 22°34.118'N , 105°52.537'E , 1048 m, 12.iv.2014, VN13, Cognato, Smith, Pham, ex large felled Pinus sp. (MSUC, 1). Diagnosis. 2.0-2.5 mm long (mean = 2.26 mm; n = 5); 2.33-2.78 x as long as wide. This species is distinguished by the elytral summit armed by two pairs of large denticles, one pair on interstriae 2 and the other on interstriae 3; pronotum longer than wide; declivity appearing strongly bisulcate; declivital interstriae 1 and 3-6 clearly convex giving the declivity a rugged appearance. Similar species. Diuncus haberkorni , D. mucronatulus , D. quadrispinulosus . Distribution. China* (Guizhou*, Hong Kong*, Jiangsu*), Indonesia (Java), Japan, East & West Malaysia, New Guinea, Philippines, Thailand, Vietnam*. Host plants. Polyphagous ( Browne 1961b ).