An illustrated key to all Madeiran species, based on both external and aedeagal characters is presented. M. pseudolongicornis n. sp., M. portosanctanus n. sp., M. wollastoni Fauvel and M. johnsoni Wollaston are treated. (In addition also M. monilicornis Wollaston and M. longicornis Mäklin are figured). Data on biology and distribution of the species are given.