2003 年 18 巻 1 号 p. 25-30
When sticky traps were placed at the inside edge of closed windows，a closed door，and in a mail box attached on the door，very small insects with body lengths of about one millimeter or less were caught depending on the operation of a ventilation fan in the room. No insects were caught when the ventilation fan was not operated. This suggests that minute contaminant insects invade structures through small crevices around closed doors，windows，and even incomplete walls and floors，depending on the operation of ventilation fans. Moderate sized insects also invaded another room near by through an incompletely closed window depending on the operation of the same ventilation fan above used. Substantial number of insects even went out during the fan was stopped. The dominant insects were moth flies, chironomid midges, and fungus gnats; this coincides with a trend which is often observed in many industrial facilities.
