Megadrypta mirabilis n. gen. n. sp. from Guangdong (China) is described. The new genus is distinguished from all known genera by a combination of large body size, pronotal bead well marked, sloping shoulders, reduced hind wings, smooth claws and stylomeres, and a large number (7-8) of periscutellar pores. Some remarks are made upon the relationships with the other genera of Dryptini, raising to the genus rank the taxa Nesiochypta Jeannel, 1949 and Prionodrypta Jeannel, 1949, formerly regarded as subgenera of Drypta Latreille, 1796. A new key to all the genera of this tribe is proposed.