Biocontrol of Water Hyacinth: Insights into Neochetina eichhorniae Warner and N. bruchi Hustache

Eichhornia crassipes (water hyacinth) is one of the world’s most invasive aquatic weeds, posing severe ecological, economic, and social challenges in infested regions. Among the various management strategies, the curculionid weevils Neochetina eichhorniae and N. bruchi have emerged as the most effective and widely utilized biological control agents. Adult weevils defoliate plants, while larvae tunnel through petioles and stolons, weakening plant structure, enhancing disease susceptibility, and eventually leading to plant collapse. Although natural enemies such as nematodes, fungi, and microsporidia can negatively affect weevil populations, large-scale releases have consistently resulted in substantial reductions in water hyacinth biomass. Integration of Neochetina species with fungal pathogens, herbicides, or manual/mechanical removal enhances control efficacy, while simulation models provide valuable insights into population dynamics and release optimization. Overall, Neochetina weevils represent an environmentally sustainable, cost-effective, and long-term management tool for water hyacinth control. Future research should emphasize synergistic use with microbial agents, long-term monitoring under climate change scenarios, and the application of molecular and remote sensing technologies to refine and strengthen management strategies.