Effect of different types of prey on fecundity of the phytoseiid mite Typhlodromips swirskii (Athias-Henriot), a potential biological control agent for horticultural greenhouse pests in the Canary Islands 1Estrella Hernández-Suárez, 1Mª del Cristo Velásquez, 1Mª Inmaculada Paz-González, 2Francisco J. González, 1Aurelio Carnero and 3Francisco J. Ferragut 1Instituto Canario de Investigaciones Agrarias, Dpt. De Entomología. Crta del Boquerón s/n., 38080 La Laguna –Tenerife (Canary Islands), Spain. 2Koppert Canarias, C./ Roble s/n, Polígono Industrial de Arinaga, Agüimes-Gran Canaria (Canary Islands), Spain. 3Instituto Agroforestal Mediterráneo, Dpt. Ecosistemas Agroforestales, Universidad Politécnica, C../ de Vera 14, 46022 Valencia, Spain. Abstract: An increasing number of commercial greenhouse growers from the Canary Islands employ beneficial insects to control pests, but effective biological control of some horticultural pests represent a handicap to the implementation of Integrated Pest Management Programs in our archipelago. That is the case of the western flower thrip Frankliniella occidentalis (Pergande) in cucumber, the broad mite Polyphagotarsonemus latus (Banks) in sweetpepper, and the tomato ruset mite Aculops lycopersici (Massee) and the glasshouse whitefly Trialeurodes vaporariorum (Westwood) in tomato. Typhlodromips swirskii (Athias-Henriot) has shown a high efficacy against the sweetpotato whitefly Bemisia tabaci (Gennadius), and it has been evaluated as biocontrol agent of many other pests (Tetranychus urticae Koch, Eriophyes dioscoridis Soliman & Abou-Awas, Thrips tabaci Lind, Aphis gossypii Glover, etc.). This present work aim to study whether T. swirskii could be used for biological control of different key pests in commercial horticultural greenhouses in the Canary Islands. As the first step, preliminary laboratory trials have been conducted to study the suitability of different types of preys and non-prey food substances (pollen) on the biology of a commercially available strain of the phytoseiid predator T. swirskii. We present the effect of the food type on the predator fecundity. The preys included in the study were Frankliniella occidentalis, Trialeurodes vaporariorum, Polyphagotarsonemus latus and Aculops lycopersici. The study has been conducted under a joint ICIA- Koppert Biological Systems research project. Key words: Typhlodromips swirskii, biological control, Canary Islands.