Behavioral responses of insect pests attacking leaf vegetables under ultraviolet-absorbing plastic films with different wavelengths transmitted and ultraviolet-transmitting films

The movement of five leaf vegetable insect pests, Athalia rosae ruficornis, Phyllotreta striolata, Plutella xylostella, Chromatomyia horticola and Thrips tabaci were examined with an ultraviolet (UV)-transmitting plastic film and four UV-absorbing films, which blocked wavelengths below 340 nm, 360 nm, 370 nm or 380 nm. The insects were placed in an experimental box covered with the UV-transmitting film and the UV-absorbing film; their choice behaviors were observed. The numbers of A. rosae, P. striolata and T. tabaci distributing in the area under all the UV-absorbing films tested were smaller than those under the UV-transmitting films. Movement of P. exlostella and C. horticola into areas under films blocking UV wavelengths below 360 nm,370 nm and 380 nm was suppressed compared to that with the UV-transmitting films. From these findings, we would expect the five insect pests tested to avoid light conditions that do not contain UV wavelengths of 360 nm and less.