Closely related species of Parasitengonae (Acari: Prostigmata) inhabiting the same areas: features facilitating coexistence

摘要

From samples taken at different localities in northern Germany during the years 1989-1997 it became evident that parasitengone mites belonging to the same genus often occur sympatricaily. Thirty-seven species were found, belonging to 25 genera, of which 26 species were examined with regard to the validity of species status, their life history and their environmental demands. In all of the closely related co-occurring species, most characters (e.g. nutrition of postlarval instars) are only slightlydifferentiated or identical whereas interspecific differences were found concerning the parasitic phase of the larvae (e.g. host range, annual appearance of larvae). This is an indication of the strong selection pressure correlated with larval parasitismoccurring today and which had occurred during the evolutionary history of the main parasitengone subgroups. The data show that those taxa of Parasitengonae which have retained the ancestral life-style and type of parasitic association, differentiation in larval parasitism has been the key process facilitating co-occurrence of closely related species in the same biotope.