A new species of Mengenilla Hofeneder, 1910 (Strepsiptera, Mengenillidae) from southern Tunisia is described. Mengenilla moldrzykisp. n. can be distinguished from congeners by a slightly emarginated posterodorsal margin of the head, compound eyes with a light tan dorsal part, mandibles with a narrow distal part, and a v-shaped pronotum. With the description of Mengenilla moldrzykisp. n., eleven valid species of Mengenilla are currently recognised. Mengenilla moldrzykisp. n. is the third species of the genus with known females and female puparia. First instar larvae, endoparasitic larval stages, the male puparium and the host are unknown. The new species is also the first strepsipteran with a fully sequenced genome.
Keywords: Mengenilla; Mengenillidae; new species; taxonomy.