Attractiveness of Green Stink Bugs Nezara spp. to Ultraviolet-Based Multichromatic Light Traps: Synergistic Effects of Ultraviolet and Blue Light

Numerous insect species exhibiting positive phototaxis are strongly attracted to ultraviolet (UV) light. However, several heteropteran stink bugs, including <i>Nezara viridula</i> (L.) and its congener <i>Nezara antennata</i> Scott, show stronger attraction to traps combining UV and green light than to monochromatic UV light traps. To examine the role of visible light wavelengths in enhancing UV attraction, we evaluated the attractiveness of blue (469 nm), green (523 nm), orange (613 nm), and red (632 nm) light in combination with UV light (396-400 nm), as well as a monochromatic UV light source, under field conditions targeting <i>Nezara</i> bugs. Traps combining UV and blue light captured nearly three times more <i>Nezara</i> bugs than UV-only light traps. Conversely, traps combining orange or red and UV light captured equal to or fewer bugs than monochromatic UV light traps, indicating no enhancement in attraction with these color combinations. Furthermore, monochromatic blue light alone showed very weak attractiveness, indicating that blue light synergistically enhanced the attractiveness of UV light to bugs. Strong attractiveness to traps combining UV and green light was confirmed in the lepidopteran moth <i>Pleuroptya ruralis</i> (Scopoli), suggesting that multiwavelength light sources may be effective in attracting insect species beyond Heteroptera. These findings highlight the value of multiwavelength light traps, particularly traps combining UV and blue light, for improving stink bug monitoring and pest management.