Ecological Notes on Parnassius glacialis BUTLER in Ibaraki Prefecture

Abstract

In this paper we noted the life cycle and behavior of Parnassius glacialis BUTLER inhabiting a limited grass bed along the Kokai River (alt. 8 m) in Ibaraki Prefecture. The distinctive feature observed in the survey is that Parnassius glacialis BUTLERis flooded every year at the stage of eggs, and spends its whole life within the habitat definitely limited. The survey revealed that the yearly decrease of the population hints the impossibility of the permanent existence of Parnassius gracialis BUTLER in the above-mentioned grassland.