Effect of light colours and weather conditions on captures of <i><scp>S</scp>ogatella furcifera</i> (<scp>H</scp>orváth) and <i><scp>N</scp>ilaparvata lugens</i> (<scp>S</scp>tål)

Abstract

Abstract To study the phototactic responses of white‐backed planthopper , S ogatella furcifera ( H orváth) and brown planthopper, N ilaparvata lugens ( S tål) to different wavelengths, four colours of light traps (blue, green, yellow and red light‐emitting diodes) were placed in the same rice field along with a traditional black light trap. This study revealed that S . furcifera and N . lugens are more attracted to blue and green lights than that to yellow and red lights. During the 24 nights, compared with the black light trap, the blue LED trap could catch more rice planthoppers at 17 nights. Furthermore, catches of other species (moths and beetles) were substantially reduced in blue LED light traps. Multiple regression models were developed to assess the effect of weather factors on light trap catches of rice planthoppers. Rainfall and mean air temperature at a night mainly affected light trap catches of S . furcifera . Higher rainfall and lower temperature increased light trap catches of S . furcifera . However, wind speed was the main factor affecting the catches of N . lugens, and the lower incidence of catches was found in the night when wind speed exceeded 3.08 m/s. S. furcifera may be flying against wind at light wind nights by 0.3–1.5 m/s, whereas N. lugens may be flying down at strong wind nights by 1.5–3.08 m/s. Relative humidity did not significantly influence on trap catches. Consequently, light wavelengths, precipitation, average temperature and wind should be considered when monitoring rice planthoppers by light traps. Therefore, the blue LED light traps are worth using for monitoring planthoppers.