Surveys for Pathogens of Monoecious Hydrilla in 2013
ARMY CORPS OF ENGINEERS VICKSBURG MS ENGINEER RESEARCH AND DEVELOPMENT CENTER
Pagination or Media Count:
This technical note describes 2013 survey results for pathogenic agents on monoecious hydrilla. There are two biotypes of Hydrilla verticillata L.f. Royle hydrilla in the United States. The pistillate dioecious hydrilla biotype was introduced from Sri Lanka into Florida in the 1950 s Schmitz et al. 1990. It has spread throughout the Southeast United States, as far west as Texas and into parts of California Madeira et al. 2004. Monoecious hydrilla was first discovered in Delaware in 1976 and later in the Potomac River Haller 1982, Steward et al. 1984. It has now expanded its distribution through the Atlantic States and northward to Maine Madeira et al. 2004. Separate populations have been reported in Iowa, Ohio, Indiana, Wisconsin, Kansas, Missouri, California, and Washington State Nonindigenous Aquatic Species NAS 2011. The Washington State population no longer exists due to an aggressive eradication program.1 It is believed that populations in Iowa and Wisconsin have also been eradicated.2 Recent invasions have appeared in Lake Cayuga and at Tonawanda CreekErie Canal, both in upstate New York Cornell Coopertive Extension CCE 2011, Lansing Star 2012. Shortly after its discovery in 1982, Steward et al. 1984 predicted that monoecious hydrilla had the potential to invade all of the lower 48 states and southern and central Canada. Balciunas and Chen 1993, after surveying for biocontrol agents in Asia and examining herbaria in the region, also indicated that hydrilla could become widespread in North America, including Canada and parts of Alaska. Although not known to exist in Minnesota, Maki and Galatowitsch 2008 ran a CLIMEX model a software program that predicts the effect of climate change on species distribution that indicated the state was at risk for invasion of monoecious hydrilla.
- Biological Oceanography