Notes on the subfamily Pleganophorinae, with the description of a new species of the genus Trochoideus Westwood, 1833 (Coleoptera, Endomychidae) from China.

The subfamily Pleganophorinae (Coleoptera, Endomychidae), an unusual group distinguished by its distinctive antennal morphology, is reported for the first time in mainland China with the description of Trochoideus sinensis sp. nov. from Guangdong and Jiangxi and the first records of T. desjardinsi Guérin-Méneville, 1838 and T. tonkineus Strohecker, 1980 from Hainan. Additionally, the male of Dadocerus nitidus Arrow, 1920 is discovered for the first time, and the sex assignment in the original description is corrected. Morphological diagnoses are augmented by comparative analyses of antennal dimorphism and mitochondrial cytochrome c oxidase I (COI) gene barcoding data. A key to the Chinese species of Trochoideus is provided.