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

## TL;DR

Combining ultraviolet and blue light attracts more green stink bugs than ultraviolet alone, improving pest control strategies.

## Contribution

The study identifies blue light as a synergistic enhancer of ultraviolet light attractiveness for Nezara stink bugs.

## Key findings

- Traps combining UV and blue light captured three times more Nezara bugs than UV-only traps.
- Blue light alone had weak attractiveness, but enhanced UV light's effect when combined.
- Orange and red light combinations with UV did not improve capture rates.

## Abstract

Many light-attracting insects are attracted to ultraviolet (UV) light. However, certain stink bugs, including the Nezara species, show a stronger preference for light sources combining UV with green light than for UV light alone. To investigate this, we tested whether adding visible light wavelengths to UV light enhanced capture efficiency. We compared the number of Nezara bugs captured in traps combining four visible light sources (blue, green, orange, and red) with UV light against traps using only UV light. Traps combining UV and blue light captured approximately three times more stink bugs than UV-only traps. Interestingly, blue light alone attracted very few bugs, indicating that it enhances UV light attraction rather than acting independently. In contrast, combining UV with orange or red light did not increase capture rates relative to UV-only traps, indicating that these wavelengths do not enhance the attractiveness of UV light. These findings strongly indicate that, for certain insect species, combining UV with specific visible wavelengths, such as blue, can be substantially more effective than UV light alone. This multiwavelength approach may improve trap effectiveness and inform the development of optimized pest control strategies.

Numerous insect species exhibiting positive phototaxis are strongly attracted to ultraviolet (UV) light. However, several heteropteran stink bugs, including Nezara viridula (L.) and its congener Nezara antennata 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 Nezara bugs. Traps combining UV and blue light captured nearly three times more Nezara 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 Pleuroptya ruralis (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.