Abstract
The effect of the direction of radiation with yellow pulsed-light from LEDs with a 20 % duty-cycle on the control of the common cutworm (Spodoptera litura) was investigated for asparagus in open field culture. Three radiation directions, downward, upward and outward from the periphery of the field, were compared. The percentage of asparagus stalks damaged by common cutworm larvae in fields in which those three light radiation directions were deployed decreased significantly compared to a control area with no radiation. Among the fields in which yellow pulsed light from LEDs with a 20 % duty-cycle was present, herbivory rates of asparagus stalks were lower or equal in those fields with upward and outward light compared with the field in which downward light was deployed. Additionally, the number of larvae per stalk and the number of male adults captured by pheromone traps showed the same tendencies as the herbivory rates. These results indicated that a more appropriate direction for radiation with light could exist in attempts to control moth predation by illumination.