Choosing light for a perfect date? Light spectra have different impacts on mating and developmental performances of the generalist beneficial Orius insidiosus (Say)

Supplemental lighting (SL) is a powerful tool to both promote crop productivity and disrupt pest activity in greenhouses. However, SL optimization regarding beneficial insects remains overlooked. After screening various light spectra based on predation efficiency of O. insidiosus, we evaluated the impact of selected spectra on predator’s life cycle, from mating to the new adult generation. Predators were exposed to daily light sequences via tunable LED devices. Mating behaviors were assessed from video recordings before couples were exposed to tested SL spectra to determine development-related parameters (fecundity, fertility, total development duration and adults’ sex ratio). Surprisingly, spectra that increased the number of mating events didn’t produce more offspring. Nevertheless, SL addition after a 12h exposure to solar light significantly improved the monitored developmental parameters. More specifically, we identified a Blue-Red light mix enhancing both O. insidiosus predation and developmental performances, thus paving the way towards SL-mediated biocontrol optimization.