[Objectives]  To investigate the color preferences and diurnal rhythm of the bean flower thrip, Megalurothrips usitatus (Bagrall). [Methods]  The preferences of adult M. usitatus for sticky traps of ten different colors; white, black, gray, red, green, yellow, blue, purple, pink, and light blue, were determined in both the laboratory and the field, and the most preferred colors were quantified by converting RGB values to virtual wavelengths. [Results]  Blue sticky traps were the most attractive to M. usitatus, followed by light blue sticky and purple traps. A virtual wavelength of 470 nm [RGB (0, 195, 255)] was significantly more attractive to M. usitatus than other colors in laboratory tests. The diurnal activity of adult bean flower thrips had an obvious rhythm. The peak of daily activity was from 8:00-10:00 am and they were inactive at night. [Conclusion]  These results provide theoretical and technical support for bean flower thrip monitoring and the integrated management of this pest.