Nonindigenous Diseases and Parasites in Freshwater Systems

Nonindigenous Diseases of Plants

The distinction of nonindigenous from native pathogens of plants is difficult (G. E. Buckingham, Research Entomologist, Biological Control Laboratory, U.S. Department of Agriculture, Gainesville, Florida, personal communication). Only if the pathogen is recovered from the plants when the shipping container is opened, importation of the pathogen can be determined. Many reported pathogens were identified only to genus and most genera are common worldwide. In Florida, the list of pathogens includes many on common nonindigenous plants like waterhyacinth, hydrilla, alligator weed, and others that are well established in the field and thus susceptible to native Florida pathogens. Alfieri et al. (1994) identified eight imported nonindigenous aquatic plant species in four families on which pathogens have been reported (Table 1). Those pathogens are supposedly nonindigenous.