Control of aphids and whiteflies on Brussels sprouts by means of UV-absorbing plastic films

Use of UV-absorbing films has recently developed into a promising tool to control insect pests under greenhouse conditions. UV-absorbing films that significantly reduce transmission of UV-A and UV-B natural solar radiation can interfere with vision of herbivorous insects. The exclusion of UV from natural sunlight hampers flight initiation, dispersal, host finding and establishment, hence affects the population build-up. To study the effects of UV-absorbing films on population dynamics of Aleyrodes proletella and Brevicoryne brassicae, eight walk-in tunnels covered either with UV-absorbing or UV-transmitting films were constructed. In each tunnel, 49 Brussels sprouts seedlings were planted. Densities of the pest insects and their parasitation rates were determined on ten randomly chosen plants per tunnel two times per week. UV-absorbing materials significantly reduced the population densities of A. proletella and B. brassicae. Parasitation rates of the pests were not reduced under UV-deficient conditions. The results indicate that UV-absorbing films can be a very powerful tool to control pests in Brassica crops.