The aim of this study is to observe the attraction of four colored lights against beet armyworm (Spodoptera exigua). The visual preference of the beet armyworm for light-emitting diodes (LEDs) was examined by LED equipped phototactic chamber in the dark room at 27 ± 0.5°C and 60 ± 5% relative humidity. Evaluated specific wavelengths of LEDs were blue (470 ± 10 nm), green (520 ± 5 nm), yellow (590 ± 5 nm) and red (625 ± 10 nm), and compared with that of the commonly luring lamp used fluorescent (380-800 nm) which served as controls. The light intensity was tested at 20, 40, 60, 80 and 100 lx, and light-exposure time was determined at 20, 40, 60, 80 and 100 min. All of the light treatments with 40 lx intensity and the 60 min light-exposure time showed the highest attraction rate to S. exigua. Based on attraction rate of the green LED (88.9%) was the most attractive to S. exigua, followed by blue LED (81.1%), yellow LED (63.3%) and red LED (56.7%). In comparisons with LED and fluorescent light, the attractive rate to green LED against beet worm was more effective than that of fluorescent (80%) light. Overall, these results indicated that the eco-friendly LED could be a more effective substitute for the chemical free insect pest control system because of the various advantages.

• Hoi-Seon Lee(Department of Agricultural Chemistry, Chonbuk National University)