In Japan, the damages by the subterranean termites (Coptotermes formosanus and Reticulitermes speratus) are more common. Recently the more attention is paid to the less- or non-chemical methods for termite control. As a non-chemical treatment, physical barriers using particles such as gravels were investigated in terms of environmental safety, cost effectiveness, and duration of performance, and the physical barriers using some particles have been practically used in a few countries except Japan. In this study, penetration of termites of R. speratus into seven physical barriers of different particulate materials such as pelletized stone powder, pelletized zeolite, crushed zeolite, calcite, crushed silica gel, silica gel beads, and glass beads, and sandy loam as a control, were investigated under the floor of experiment house for seven years. Layers with particles of pelletized zeolite (1.00 to 4.00mm in diameter), crushed zeolite (1.50 to 3.00mm), calcite (1.50 to 3.00mm), crushed silica gel (1.50 to 3.00mm), and silica gel beads (1.50 to 3.00mm) prevented termites from passing through. On the other hand, for all of the layers with particles passed through by R. speratus, only the penetrations at the corner part were observed, because of the gaps at the corner part where termites could pass through. It was considered that there were gaps at the corner part, since the wood stakes under the corner parts of the layer with particle was completely consumed by termites and the particles flowed into cavities.

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