The South American rice water weevil Oryzophagus oryzae (Costa Lima) (Coleoptera: Curculionidae) is a key pest of irrigated rice in Brazil. Light traps could be used as an integrated pest management (IPM) strategy since these weevils have strong phototropism. Thus, the aim of this study was to search the attractiveness of LEDs of different wavelengths to O. oryzae to define the best light-emitting diodes (LED) arrangement to build the lamp of photovoltaic light traps. LEDs of different wavelengths were tested in a dark room with a hexagonal arena with exits to light sources. Groups of 200 insects were released in the center of the arena and captured at the end of exposure time in plastic bags placed in the exits. The LEDs in the short-wave band of the light spectrum (365 and 460 nm) and white LEDs, as well as the light mix of 365 with 460 nm or white LEDs, were attractive to O. oryzae. Beyond the LEDs with ultraviolet (UV) spectrum, the LEDs above 380 nm were the most attractive and, this way, might be used to build LED lamps of photovoltaic light traps.

No abstract

This study aimed to present the design and field test results of an LED (light emitting diode) lamp for integrated pest management (IPM) and other entomological studies. The light spectrum of the LEDs was tuned to optimize insect attraction and lower energy consumption. An electronic circuit with control software was integrated with the lamp, enabling it to operate in standalone mode, automatically identify night and day, monitor and control the battery charge with energy from a photovoltaic solar panel, protect the battery against over-discharge, and provide feedback about the operating status of the system. Additionally, energy consumption is about five times lower than that of the fluorescent lamp, reducing the battery and solar panel size needed for its energy supply. In the 2017/2018 growing season, the smart LED lamp was installed in a Sonne light trap in an irrigated rice field, and the total number of insects captured was compared with the number collected in a conventional light trap fitted with a traditional 15 W black light fluorescent lamp. Total captures in the Sonne trap were approximately three times greater than in the conventional system.