M. ellenae sp. n. is described and illustrated from Hong Kong (holotype 6: Sha Lo Tung, 24-VI-1995). It is compared with its closest congeners from China and South East Asia. Further records and additional descriptive notes are given for M. rapida Martin. New records are provided for Idionyx victor Hamalainen and I. claudia Ris is recorded from Hong Kong for the first time.