Effects of Ultraviolet-Absorbing Greenhouse Plastic Films on Flight Behavior of Bemisia argentifolii(Homoptera: Aleyrodidae) and Frankliniella occidentalis(Thysanoptera: Thripidae)

Abstract

Several clear polyethylene film products, developed specifically for greenhouse use, have high UV-absorbing abilities, while allowing high transmission of visible light. We examined the effects of these plastics on insect flight behavior. Four high UV-blocking products from 2 manufacturers were compared with their respective standard plastics. Insect species tested were the whitefly, Bemisia argentifolii Bellows & Perring, and the western flower thrips, Frankliniella occidentalis (Pergande). In choice experiments, when insects were released from a black box at the center of 2 tunnels, sticky traps caught 85–94% of released whiteflies and 90–98% of released thrips inside standard tunnels when compared with UV-blocking tunnels. This indicates a distinct preference of both whiteflies and thrips to enter tunnels that transmit higher levels of UV light. In no-choice experiments, when insects were released at one end of a single tunnel covered with 1 type of plastic, there was no significant difference among types of plastic in the number of whiteflies or thrips caught, indicating that there was no obvious negative effect of UV-blocking plastic on the ability of insects to fly. These results indicate that greenhouse plastics may have significant influence on the initial attraction of insects into greenhouses. It will be important to study these effects in more detail to understand the mechanisms underlying UV-light taxis and the application of this phenomenon to management of insect pests in greenhouse crops.