The use of UV absorbing mesh screens in Israel has proved effective in protecting crops against Bemisia tabaci, Liriomyza trifolii and Franklinella occidentalis and the virus diseases that they can introduce. In one experiment using a UV absorbing 50-mesh, the number of plants infected with leafminers was 52% as compared with 98% in the control. The UV absorbing mesh screens are considerably more effective than conventional mesh anti-virus screens. A 40-mesh size is needed against aphids and leafminers. A 50-mesh may only be partly effective against Frankliniella occidentalis. However it must be emphasised that closing a greenhouse with partial barriers will result in an increase in temperature and humidity which may cause outbreaks of fungal or bacterial diseases. At all events, the use of UV absorbing materials (including UV absorbing polythene cladding) has also been found effective in reducing insect infections. It appears that the elimination of UV light from the light spectrum interferes with the orientation of white flies and other insects, being controlled by photoreceptors in the insects’ eye. The studies suggest that UV-absorbing films and nets can form an integral part of integrated pest management and can therefore contribute to reduced application of chemical insecticides. www.phyoparasitca.org. E-mail: vpantig@volcani.agri.gov.il