Eichhornia crassipes, commonly known as water hyacinth, is an aquatic plant native to the Amazon basin. It is often considered a highly problematic invasive species outside its native range. It is a major freshwater weed in most of the frost-free regions of the world. It has been widely planted as a water ornamental around the world because of its striking flowers. Wherever it has encountered suitable environmental conditions it has spread with phenomenal rapidity to form vast monotypic stands in lakes, rivers, and rice paddy fields. Then it adversely affects human activities (fishing, water transport) and biodiversity. It is impossible to eradicate, and often only an integrated management strategy, inclusive of biological control, can provide a long-term solution to this pest.