The effect of exposure to a pulsed yellow light-emitting diode (LED) on the adult flight behavior of the cotton ballworm, Helicoverpa armigera

Abstract

We aimed to clarify the pulse conditions of a yellow LED that can be pulsed at the high speed required to control noctuid moths without suppressing the blooming of chrysanthemum. We used a lemon-yellow LED (central wavelength: 571 nm) of similar wavelength to yellow fluorescent light, with an intensity of 20 mW/m2 and pulsed-LED light period of 20 ms. We measured the flight activity of adult Helicoverpa armigera (Hübner) under various light to dark period ratios of the LED pulse: 20 ms: 0 ms (continuous lighting), 20 ms: 40 ms, 20 ms: 80 ms, 20 ms: 160 ms, 20 ms: 400 ms and these were compared with dark conditions 0 ms: 0 ms without illumination, using an actograph system. As a result, Helicoverpa armigera became accustomed to the LED lighting conditions over time and the number of flight activities gradually increased in unmated females in 20: 0, 20: 160 and 20: 400 groups and in unmated males in 20: 0 and 20: 400 groups over one day. However, in the 20: 40 and 20: 80 groups, Helicoverpa armigera adults, either unmated females or males, did not become accustomed, but flight activity was clearly controlled over five continuous days. It was found that the flight of adult moths was strongly suppressed under the conditions of 20: 40 ms and 20: 80 ms pulsed-LED light.