Here is a quick summary of the major federal agencies involved in preventing and managing invasions of damaging non-native species:
USDA Animal and Plant Health Inspection Service (APHIS)
The USDA Animal and Plant Health Inspection Service (APHIS) is responsible for preventing introduction of plant pests (insects, pathogens, slugs, etc., that attack plants) & diseases/pests that attack animals, especially livestock and poultry.
Thus, APHIS is responsible for preventing entry into the country of additional plant pests, including those that kill trees. APHIS is also responsible for detecting, containing, eradicating, and slowing the spread of plant pests that enter the country despite its prevention efforts. In carrying out these functions, APHIS regulates the movement of wood packaging, nursery stock and other types of plants, firewood, and other articles that can transport plant pests. For a lengthy discussion of APHIS’ tree-pest programs, read Fading Forests III, available here
USDA Forest Service
The USDA Forest Service is responsible for managing the hundreds of non-native tree-killing pests that have established and become more widespread over the 400-plus years since European settlement began. The Forest Service also assists APHIS (see above) in developing and implementing effective programs to counter invading pests and the pathways (such as wood packaging or firewood) by which they enter the U.S. or spread once in the country.
Nearly all non-native forest pests first invade the country in cities and suburbs, not in the wildland forests managed under the National Forest System. This is because non-native forest pests are brought to America through importation of stuff that we Americans buy. And 80% of us live in cities and suburbs! Read more about how forest pests enter the country by reading the fact sheets posted here.
Once introduced to a particular place, the most significant of these pests threaten trees across the country. Consequently, the USFS leads a national-level response that coordinates efforts by states, stakeholders, universities, etc. to protect our vulnerable forests vulnerable. Read more about USFS pest-management efforts: USFS information on forest health or research. Or read our independent analyses: brief or in-depth
US Department of the Interior Fish and Wildlife Service
Under the Lacey Act (18 U.S.C. 42), the Secretary of the Interior is authorized to regulate the importation and transport of species, including offspring and eggs, determined to be injurious to the health and welfare of humans, the interests of agriculture, horticulture or forestry, and the welfare and survival of wildlife resources of the U.S. Wild mammals, wild birds, fish, mollusks, crustaceans, amphibians, and reptiles are the only organisms that can be added to the injurious wildlife list.
Until spring 2017, the Lacey Act was interpreted to prohibit not only importation of species listed as injurious but also their transport between the States, the District of Columbia, the Commonwealth of Puerto Rico, or any territory or possession of the U.S. The Service was authorized to issue permits allowing for the importation or transportation of live specimens of injurious wildlife and their offspring or eggs for bona fide scientific, medical, educational, or zoological purposes.
In April 2017, the DC Circuit Court of Appeals ruled in United States Association of Reptile Keepers, Inc. et al. v. Ryan Zinke, Secretary of the Interior and United States Fish and Wildlife Service, that the prohibition on moving injurious species within the United States applies only to animals moved between the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States and the 49 continental United States. The FWS lacks statutory authority to prohibit movement across State lines among the 49 continental States.
As before, an injurious wildlife listing would not prohibit intrastate transport or possession of that species within a State, where those activities are not prohibited by the State.
Current list of Injurious Wildlife Species
General injurious wildlife evaluation process
For a useful summary Fact Sheet: Injurious Wildlife - A Summary of the Injurious Provisions of the Lacey Act
USDA headquarters, Washington, D.C.