Habitat status of the grasshopper, Eusphingonotus japonicus (Saussure), in Kanagawa prefecture, Japan

The habitat status of the grasshopper, Eusphingonotus japonicus, an endangered species in Kanagawa Prefecture, was investigated at one large remaining site in the riverbed of the Nakatsu River in Aikawa-cho, Kanagawa Prefecture in the autumn of 1996. There were remarkable differences between the species composition of plants and orthopterans at three observation areas in the riverbed, and E. japonicus was found only in the area where the plant cover was low; other grasshoppers, Locusta migratoria and Oedaleus infernalis, predominated. It is suggested that the change in vegetation caused by plant colonization of the riverbed area may affect the occurrence of E. japonicus as well as other orthopteran species. The destruction and fragmentation of habitats due to human activity such as riverbank protection work may damage many populations of E. japonicus in Kanagawa Prefecture.