Everyone knows that lighting lamps in rice fields at night can attract and kill various pests. During its growth, rice must withstand attacks from many pests, including rice borers, leaf rollers, rice sheath bugs, whiteflies, and rice stalk borers, among a dozen others. These pests are enemies of crops and cause severe annual losses.
Farmers, through long-term practical labor, discovered that these insects are attracted to light. Utilizing this characteristic, they place gasoline lamps in the fields at night with a basin of water underneath. When insects fly towards the light and hit the lamp, they fall into the water and cannot fly away, ultimately drowning. This clever method allows people to effortlessly eliminate crop pests and ensure a bountiful harvest.
After long and careful research by scientists, it has been proven that insects are attracted to a spectrum of light that leans towards shorter wavelengths. Thus, shorter wavelengths have a greater effect in attracting insects. Based on this characteristic, scientists have recently designed a type of black light bulb (commonly referred to as a black light).
The black light looks just like the fluorescent lights we use at home, but instead of emitting white light, it emits a beautiful blue-green fluorescence. The wavelength of this light is very short, only 3650 angstroms (1 angstrom equals one ten-thousandth of a micron).
Therefore, the black light’s ability to attract insects surpasses that of gasoline lamps, ordinary electric lights, and fluorescent lights. According to experiments, a 60-volt electric light can attract rice stem borers effectively within a radius of 55 meters, but a 60-volt black light can attract pests from up to 127 meters away, more than doubling the effectiveness.