Technical Abstract: Biological control is an important component in weed management. When pursuing pathogens as a biological control agent, location is an important factor to consider where to search for an effective agent. Although there may be more risks and research to conduct, pathogens isolated from weeds in their native location may be the most efficacious. Ecological matching between invasive and native ranges will assist in finding more environmentally suited agents and assure that interactions in development between the host and pathogen are similar. Steps conducted for isolation, screening, identification and pathogen enhancement are addressed. The concerns with the use of exotic pathogens are addressed with a specific emphasis on potential host range expansions. To address this fear of host range expansions, past research and records of mycoherbicide applications, biological control of plant pathogens, and behavior of “agronomic” pathogens are examined.