Phototactic behavior of yellow stemborer and rice leaf folder moths to surface mount device-light emitting diodes of various wavelengths

Abstract

Many nocturnal insect pests exhibit positive phototaxis to the artificial lights of a certain wavelength. Identifying the phototaxis of pests is potentially useful for integrated pest management. This study examined the phototactic response of two major insect pests of paddy crops, yellow stemborer (YSB), Scirpophaga incertulas, and rice leaf folder (LF), Cnaphalocrocis medinalis moths (Lepidoptera: Pyralidae). Four monochromatic and three bichromatic surface mount device-light emitting diodes strips - ultraviolet (365 ± 5 nm), violet (400 ± 5 nm), blue (465 ± 5 nm), green (525 ± 5 nm), ultraviolet-violet (365 + 400 nm), violet-blue (400 + 465 nm), and ultraviolet-blue (365 + 465 nm) are used for the study. Based on the laboratory and field experiments, YSB moths showed the strongest attraction to ultraviolet (365 ± 5 nm) and LF attraction was highest to violet (400 ± 5 nm) lights. In bichromatic phototactic experiments, both species exhibited the strongest attraction to ultraviolet-violet (365 + 400 nm) lights. The influence of luminance intensity, adaption time in darkness, and light exposure time on the phototactic behavior of these moths are also tested. YSB and LF moths attraction rate increased with an increase in luminance intensity and violet (400 ± 5 nm) at 70 lx showed the strongest attraction. The light attraction rate of YSB was highest at 60 min of dark adaptation and 45 min of light exposure time, LF has a higher attraction rate at 60 min of dark adaptation and 30 min of light exposure time.