In the 1990's Bayer CropScience discovered the new class of derivatives of teronic acid, described as broad spectrum acaricides in the 'ketenol' group. Spirodiclofen (trade name Endivor®) and spiromesifen (trade name Oberon®) are also highly active against whiteflies. This new class of chemicals has a mode of action that interferes with the biosynthesis of lipids which leads to dehydration of insects. No cross-resistance has been found in populations od mites and whiteflies. Oberon® is considered a valuable addition to the pesticide armoury where a high level of resistance to other goups of chemical has built up in whitefly and mite populations. It is also fits well into integrated pest management systems. The chemical has a very short soil half-life of 5 days with a water solubility of 130 milligrams per litre. It is safe on beneficial insects and those used as pollinators (bees) once the spray deposit has dried on the plant or if they are not actively foraging. It is safe to use with all preditor insects except predator mites. It is non toxic to birds or mammals. It has slight to moderate activity on non-harmful mites. It is effective on all stages of Bemisia, Trialeuroides, and Tetranychus. Oberon® is most active on the larvae and juvenile stages of the pests and applications early in the season are recommended. Excellent residual activity provides long-lasting and reliable control. It should be used as part of a contro program, alternating with different insecticide applications. Oberon® has already been registered in the UK for use in protected cultivation of tomatoes and therefore there should be no difficulty for its registration for use on ornamentals in the near future according to the appropriate legislation in EU member countries. For further information, contact: Certis Europa Fax 0044 1980 626555, E-mail: certis@certiseurope.co.uk www.certiseurope.co.uk