Résumé
Invasive pests and pathogens are an undesirable consequence of international trade and travel, and often result in significant ecological and economic impacts. In Europe, the number of spider mites (Tetranychidae) is steadily increasing with the arrival of introduced species, most of which have the status of pests. During the last decades two invasive species have occasionally caused major damage to crops in Europe, namely Tetranychus evansi and Oligonychus perseae.