Opius mitis Chen & Weng, 2005 (not Fischer 1963) is a primary homonym. We here rename the species Xynobius wengi nom. n.after Dr Rui-Quan Weng for his contribution to our knowledge of the Chinese Opiinae and for his hospitality to the authors during visits to the Fujian Agricultural & Forestry University at Fuzhou. The holotype has been examined and proved to belong to the genus Xynobius Foerster, 1862.