Water hyacinth, Eichhornia crassipes Martius (Pontederiaceae) is an exotic free-floating perennial plant
that is native to South America (Figure 1). Originally introduced in 1884 for its beautiful flowers, water hyacinth has invaded most of the southern United States and many tropical and subtropical regions around the world. Water hyacinth displaces native vegetation due to its rapid growth during the summer.
Major economic impacts caused by invasion of water hyacinth include interference with navigation, irrigation and power generation. Additionally, dense mats can provide ideal mosquito breeding habitats.
Water hyacinth weevils, Neochetina eichhorniae and N. bruchi, were introduced as biological control agents to suppress the growth and reproduction of water hyacinth.
Both weevils were imported from Argentina and released in United States to help manage water hyacinth. Feeding damage caused by both species of weevils is complimentary and contributes to the suppression of water hyacinth.