The taxonomy of neotenic female strepsipterans has previously relied upon characteristics of color, measurements of the cephalothorax, and identification of the host for species identification, but these characters have proven mostly uninformative in defining species. Taxonomically important characters of females of the genus Xenos (Strepsiptera: Xenidae) are presented, which should provide for species level identification using females in the genus Xenos, and these methods should be generally applicable to other strepsipterans. Xenos kifunei, X. nigrescens, and X. peckii are re-described using these characters.