Review of the genus Warren (Geometridae, Ennominae, Boarmiini), with description of a new species from Hainan, South China.

The few already published generic features of the genus Warren, 1897 are reviewed and new-found characters are added to make the generic description more comprehensive. A new species, Liu & Stüning, is described from Hainan Province, China. It is the only species found on this island and exceptional for its conspicuous pattern, vivid coloration and some morphological characters not observed in other species before. Descriptions and illustrations of adults, their venation, and male and female genitalia are presented. An identification key and an annotated checklist of all presently known species of are provided. In addition, a DNA barcode sequence is given for the new species, and preliminary phylogenetic estimations of the genus are discussed.