Abstract
The feeding of two species of wood mice, Apodemus speciosus TEMMINCK and A. argenteus TEMMINCK, on adults of the cryplomeria bark borer and the train millipede and peanuts was studied in a laboratory from 1987 to 1989. Four out of five individuals of A. speciosus and three out of five A. argenteus attacked and ate the borers. Both species of mice did not discriminate against the sex and the size of the borers in their attacks. Functional responses of A. speciosus and A. argenteus to the borer density were HOLLING'S Type II and III, respectively. When the borer density was at a low level, A. speciosus showed a greater preference for the borer. When the level of borer density was high, however, the preference of the mice for the borer differed significantly among individuals depending on their innate characters. A. argenteus showed an equal preference for the borer when the borer density was not high. When the borer density level was high, the preference of A. argenteus differed among individuals as in the case of A. speciosus. Four out often individuals of A. speciosus ate the millipede. The preference for the millipede increased with its increasing density, whereas A. argenteus did not eat them at all.
