Combination of UV and green light synergistically enhances the attractiveness of light to green stink bugs Nezara spp

The southern green stink bug Nezara viridula and its congener N. antennata are important agricultural pests worldwide. These species show positive phototaxis and their compound eyes have high sensitivity to UV and green lights. The attractiveness of monochromatic UV, green lights and combined UV and green light to stink bugs was investigated under field conditions. The number of stink bugs caught increased with the number of UV LEDs, but very few bugs were caught using green light, irrespective of the number of LEDs. However, the most stink bugs were caught when both colors were combined. These results indicate that monochromatic green light is less attractive to Nezara bugs, but when mixed with UV light, it synergistically enhances the attractiveness of UV light. This finding contributes to the construction of reliable and highly specific light traps to monitor Nezara bugs. The addition of green light hardly affected the attractiveness of the UV light to other insects, such as Anomala beetles, which are often caught in light traps. We conclude that the spectral composition of light that is attractive to nocturnal insects depends on the species, hence it is possible to make ecologically friendly light traps that are target specific.