Invasive alien species (often IAS in the literature) are those species introduced to an area outside their normal or native range, either purposefully or by accident, whose colonization causes significant harm. The species may become weeds, pests or pathogens, affecting both human interests and natural systems, and impacting agricultural systems, native ecosystems, biological diversity, or human well-being (Perrings et al. 2002; UNEP; CBD). Wellknown examples of invasive alien species include kudzu in the United States, water hyacinth throughout the tropics, zebra mussels in the Great Lakes, and European starlings in North America.