Efficacy of Red LED Irradiation for Controlling <i>Thrips palmi</i> in Greenhouse Melon Cultivation

Abstract

Irradiation of melon (Cucumis melo) seedlings with red LED light (wavelengths of 620 to 630 nm) at an intensity of 1×1018 photons m－2 s－1 decreased the number of Thrips palmi (melon thrips), a major insect pest that causes serious damage during greenhouse melon cultivation. Thrip populations were significantly lower than in treatments without LED, both with continuous 24-h irradiation and with 12-h daytime (06:00 to 18:00) irradiation. Transplanted seedlings were also irradiated with red LED light of two different intensities (4.7×1018 photons m－2 s－1 or 1.0×1018 photons m－2 s－1) in two cultivation environments (glass or plastic greenhouse). These findings suggest that irradiation with red LEDs may be an effective means of controlling Thrips palmi in greenhouse melon cultivation.