Ecological significance of parthenogenesis in collembola

The occurrence of parthenogenesis in springtails of the Palaearctic was studied. Parthenogenetic species were recorded in all main phylogenetic lines and were more abundant in the families that included species with euedaphic life forms. Among Onychiuridae and Isotomidae, the fraction of species capable of reproducing without males was about 10–15%. The deep soil dwellers showed weaker capacities for aggregation in experiments. The parthenogenetic species comprise the majority of collembolan populations in different biotopes, up to 78% in forest soils and 50% in chernozems. Occupation of deep soil horizons and expansion of distribution ranges appear to be the result of biological progress of the species which have switched to parthenogenesis.