Regulations (pertaining to the Great Lakes region) This species is prohibited in parts of the Great Lakes including Chicago, Illinois, and Minnesota. It is not prohibited in Indiana, Michigan, New York, Ohio, Ontario, Pennsylvania, Quebec, or Wisconsin (Great Lakes Panel on Aquatic Nuisance Species 2012). Hygrophila polysperma is listed as a Federal Noxious Weed, so it is illegal to import, sell, or purchase this species in the United States (APHIS 2012).
Note: Check federal, state/provincial, and local regulations for the most up-to-date information.
Control
Biological
Triploid grass carp (Ctenopharyngodon idella) is used in combination with mechanical or chemical methods in Florida, but there are no records indicating that it was successful in eliminating H. polysperma (Cuda and Sutton 2000).
Physical
Mechanical harvesters are ineffective against H. polysperma and may encourage its spread by vegetative fragmentation (Cuda and Stutton 2000).
Chemical
Invert herbicide applications of endothal (7-oxabicyclo [2,2,1] heptane-2,3, dicarboxylic acid) plus copper have not shown to be effective in eradicating H. polysperma (Spencer and Bowes 1985).
Note: Check state/provincial and local regulations for the most up-to-date information regarding permits for control methods. Follow all label instructions.