a. Zool. Also erron. thelyotokous. [f. Gr. θηλυτόκος bearing females (f. θῆλυ-ς female + -τόκος bearing) + -OUS.] Producing only female offspring, as the parthenogenetic females of some species: opposed to arrenotokous. So Thelytoky (also thelyotoky), the production of females only in parthenogenesis.
1877. Huxley, Anat. Inv. Anim., vii. 446. The terms arrenotokous and thelytokous have been proposed by Leuckart and Von Siebold to denote those parthenogenetic females which produce male and female young respectively.
1895. D. Sharp, Cambr. Nat. Hist., V. iv. 141. The result of parthenogenesis in some species is the production of only one sex, which in some Insects is female, in others male; the phenomenon in the former case is called by Taschenberg Thelyotoky, in the latter case Arrthenotoky. Ibid., xxii. 498. Thelyotokous parthenogenesis is common in sawflies.
