ABSTRACT Utilizing the phototaxis of insects in controlling pests may accidentally eliminate natural enemies. Therefore, the aim of this study was to investigate the phototactic behaviour of Propylea japonica Thunberg (Coleoptera: Coccinellidae). First, we explored P. japonica responses to seven monochromatic light sources ranging from 365 to 655 nm. Along the tested light spectrum, the highest response was elicited at 365 nm (ultraviolet), followed by 465 and 525 nm. Subsequently, we examined the combined influence of wavelength and intensity on insect responses. When 365 nm light intensity is 10 lx, the phototactic response is reduced. However, the selective preference for 365 nm increased with increasing light intensity. Finally, the behavioural responses to light intensities ranging from 1 to 5000 lx (365 nm) and observed a clear preference for higher light intensity (1000 to 5000 lx). Our results suggest that light intensity plays a more important role than wavelength in mediating the phototactic behaviour of P. japonica in various light environments. This research can contribute to designing novel light traps for insect pests that avoid collecting their natural predators.