Abstract
Ecological aspects of three horizontal orb weavers, Tetragnatha praedonia, T. japonica and T. pinicola, were investigated. Both T. praedonia and T. japonica were distributed mainly upstream, though the former was distributed more upstream than the latter. T. pinicola was distributed mainly downstream. These species hunted mainly in evening and night, though the daily activity patterns differed to some extent from one another. There were clear differences in the web height and the scaffolds. The role of such differences was considered in relation to the coexistence of the three species.
