epiproct

(Anatomical feature) a plate or projection dorsal to the anus in certain insects, generally on abdominal segment X or XI. For example in Archaeognatha, Zygentoma and Ephemeroptera, it takes the form of a long, rearwardly directed caudal filament resembling the two cerci that flank it. In the Odonata epiprocts have various functions, both in larvae, in which they may have respiratory roles, and in adults, in which they may have reproductive roles. Not all epiprocts in all insect species are homologous. Note that the term is used in other groups than insects as well, for instance Myriapoda.