thelytoky

thumb|upright=1.5|Aphid giving birth by [[parthenogenesis, the live young growing from unfertilized eggs]]

Thelytoky (from the Greek θῆλυς thēlys "female" and τόκος tókos "birth") is a type of parthenogenesis and is the absence of mating and subsequent production of all female diploid offspring as for example in aphids. Thelytokous parthenogenesis is rare among animals and reported in about 1,500 species, about 1 in 1000 of described animal species, according to a 1984 study. It is more common in invertebrates, like arthropods, but it can occur in vertebrates, including salamanders, fish, and reptiles such as some whiptail lizards.