2018 年 64 巻 p. 68-72
The effects of chrysanthemum illuminated by a red light-emitting diode bulb which has been developed for regulation of chrysanthemum flowering on the population density of Thrips nigropilosus was investigated twice in a greenhouse. Experiment 1 was started at more than three months after planting chrysanthemum（ high density of the thrips） and experiment 2 was started just after planting （low density of the thrips）. As a result, both experiments showed that the density of the thrips on plants under red LED illumination for 24 hours was significantly lower than those under incandescent lamp which is commonly used in that area. Besides, experiment 2 showed that the density of the thrips under red LED illumination for 24 hours was significantly lower than those for three hours. Our study is the first report to show that using red LED is effective for suppressing the density of T. nigropilosus on cultivating
chrysanthemum to some extent. Therefore, illumination with red LED has the possibility to be an effective and economically efficient measure for control of the thrips on chrysanthemum in combination with other measures such as insecticide applications because the red LED requires one tenth the electricity consumption of the commonly used light.