Control effects of blue and yellow light on Bemisia tabaci on greenhouse cucumbers

Bemisia tabaci is the main pest of cucumbers; it is critical to control B. tabaci using non-chemical measures for green cucumber cultivation. To explore the control effects of light on B. tabaci in greenhouse vegetables, the relationship between RGB values and the virtual wavelength was used to simulate the colors of different wavelengths on a computer. The light colors repelling B. tabaci were selected according to the selection rate of B. tabaci to different light. On this basis, the changes in the population of B. tabaci on cucumbers treated with the selected light were investigated for the control effects of B. tabaci. The results showed that the color with RGB values of 0, 0, and 255 (wavelength of 470 nm; blue) had the highest repellent rate to B. tabaci. Yellow light (54%) and green light (42%) had a strong trapping effect on B. tabaci. Adding blue light to the environment with yellow and green light could improve the selection of yellow light (68%) and green light (56%). Blue light accelerated the migration of B. tabaci from green to yellow areas. In the greenhouse cucumber field, the population of B. tabaci decreased rapidly after blue light irradiation, and the number of B. tabaci on the cucumber plants decreased significantly with increased light exposure (P < 0.05); a corrected population decline rate of 92.76% was noted after 6 days of blue light irradiation. After 10, 20, and 30 days of treatment, the corrected population reduction rates of B. tabaci on the cucumber leaves increased by 13.80%, 18.17%, and 15.10%, respectively, compared to those without yellow light. These results show that blue light has a strong repellent effect on B. tabaci, and the combination of blue and yellow light improves the control effect. Thus, adding a yellow plate may significantly increase the trapping rates of B. tabaci.