Positive Phototaxis of Pulse Weevil, Callosobruchus chinensis under the Influence of Artificial Light

Abstract

Background: Managing insect pests with less environmental hazards is one of the biggest challenges of this century; therefore, new, eco-friendly alternative ways such as electric traps, bait traps or bio-pesticides are gaining great attention. Most economic and effective method is managing agriculture pest by using light trap. Methods: In this study, the phototactic response of Callosobruchus chinensis towards different wavelengths (red 620 nm; green 520 nm; blue 470 nm) of light (LED) at different intensities (25, 50, 100 lux) and durations (2, 6, 12, 24 h) was investigated in a Y maze chamber. Phototactic responses were also observed for IR (730 nm) and UV (365 nm) at different durations (2, 6, 12, 24 h). Result: The rate of insect attraction was different for different wavelengths of light. The duration of the intended light also showed a positive response to the attraction rate of the insect, as in every case, 24 hours of duration showed the maximum attraction. The green light showed the highest attraction rate (77.78%) at an intensity of 50 lux for 24 h duration, followed by blue (74.44%) and red (65.56%) light at an intensity of 25 lux for 24 h duration (each). UV (65.56%) also showed a positive attraction at 24 h duration, but IR (52.22%) showed the least attraction. These results suggest that green and blue wavelengths can be most useful for monitoring and mass trapping of C. chinensis.