Sap-feeding insects within Hemiptera and Thysanoptera are some of the most important crop pests world-wide. Apart from the loss of yield they cause by sap depletion, saliva toxicity and soiling of the leaves, some species transmit serious plant virus diseases. Important sap-feeding species that have been introduced to the Maltese Islands include the whitefly Bemisia tabaci; the scale insects Pseudo coccus !ongispinus, Planococcus citri and lcerya purchasi; the aphids Aphis gossypii, Aphis spiraecola, Myzus persicae and Viteus viti/oliae; and the thrips Frankliniella occidentalis and Heliothrips haemorrhoidalis. For each of these pests information is provided on area of origin, present distribution, host-plant range and virus disease transmission. Control strategies undertaken in the Maltese Islands are described where relevant. Some general considerations on quarantine measures are discussed.peer-reviewe
