Five satyrine species were found around tree-sap sources of Quercus acutissima at Hino City in the suburbs of Tokyo in July and August 2002. In all species beak marked individuals were observed. The ratio of beak marked individuals to all captured ones were 40% and 13% in Lethe sicelis and L. diana, respectively in 4 days of July. This meant that a considerable number of beak marked Lethe butterflies were found in the field.
