Structural Equation Model on Attracting and Catching SCOTINOPHARA COARCTATA using an Alternative Light Trap via Light Emitting Diodes

Scotinophara Coarctata (Rice black bugs) pose risk to Philippine agriculture by decreasing rice production. Reducing rice black bugs through pesticides have risks to farmers, therefore, light traps are being used as an alternative to catch the said pest. Different kinds of light are currently being used in traps including vapor, incandescent, UV, and Light emitting diode -based lamps, which pose varying catch index given different attributes. In this study, a LED (Light-emitting diode)-based light trap prototype was used. Rice black bugs had been caught in selected nights between December 2018 to January 2019 in a specific rice field area in the Philippines. Results had been analyzed using the different LED attributes and external factors affecting the catch index. The catch size was treated dependent on attributes including: the onset and offset of the full moon, the different LED colors or wavelengths (white, blue, UV, yellow and green) and the LED illuminance. The relationship between different attributes and factors had been examined and a structural equation model had been defined using different statistical measures to map the relationships. Results of the analyses had shown higher catch index occurs with a higher light intensity regardless of attributes and factors. Results had also shown higher catch with the use of UV type wavelength LEDs, and a strong positive correlation between the wavelength and the offset of full moon. These indicate that an alternative light trap can be further developed using LEDs for attracting rice black bugs with a higher intensity and UV wavelength.