Surveys for Pathogens of Monoecious Hydrilla in 2013
Abstract
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 Creek/Erie 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2014
- Accession Number
- ADA610896
Entities
People
- Judy F. Shearer
Organizations
- United States Army Corps of Engineers