The first releases in the United States were made seven years later, following resolution of concerns surrounding nontarget feeding impacts on other plant species (Blossey 1997). For example, surveys and host-specificity testing for potential biocontrol agents for purple loosestrife began in Europe in 1986.

Potential biocontrol agents often undergo five or more years of rigorous testing to ensure that host-specificity requirements are met. Researchers must demonstrate a biocontrol agentвЂ™s host-specificity in order receive a permit for importation into the United States, issued by the USDA Animal and Plant Health Inspection Service, Plant Protection and Quarantine (USDA-APHIS-PPQ). This is known as host-specificity and is the most important precondition for an insect to be used as a biocontrol agent. To be considered for release in the United States, insect biocontrol agents must feed and develop only on the target plant, and in some cases, only on a few closely related plant species. To reduce dominance of an invasive plant within the plant community, effective biocontrol agents must focus their actions upon the target plant without harming other vegetation.

Because biocontrol agents rely on sufficient host plant populations to provide their food and habitat, they will not completely eliminate their host plant populations.Д¬ornerstone #2: Some organisms have a limited host range Biocontrol agents released into invasive plant populations must not only survive and multiply in their new environment, but they must also attack and cause enough damage to their host to cause significant population decline.Д«iocontrol is used to reduce invasive plant populations to levels below damaging thresholds, not to eradicate plant species.

Biocontrol agents vs invasive species