Preventing pest entry on plants

We’ve talked a lot here on Don’t Move Firewood about how forest pests can enter North America on or in the wood of packaging materials, such as pallets. One thing that we talk less about is that many pests also have reached our shores on imports of living plants. Examples of this problem include the hemlock woolly adelgid, winter moth, and the pathogen sudden oak death.


Until recently, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has tried to prevent new introductions by physically inspecting plant shipments. However, finding pests is very difficult because pests can be tiny, non-symptomatic at the time of import, or just simply very well hidden inside the plant. And of course it is unrealistic to inspect anything more than a minute percentage of total imports.


Protecting our forests and other natural resources for pests demands a more effective approach.


Recognizing this need, APHIS recently created a “limbo” category, known by its lengthy acronym NAPPRA (Not Authorized Pending Pest Risk Analysis). When certain types of plants from specific countries are deemed likely to harbor a particular pest, APHIS can temporarily prohibit imports of these plants via NAPPRA while it analyzes the pest risk and adopts safeguards to ensure that imported plants will be as pest-free as possible.


Last week, APHIS took the first action under this new authority by listing 107 plant genera which are likely to transport one of 13 types of pests. For example, imports of birches, dogwoods, poplars, willows, and 70 other genera of trees and shrubs from Europe and much of Asia are prohibited because they could introduce to the U.S. the citrus longhorned beetle – a close relative of the Asian longhorned beetle (ALB). Citrus longhorned beetles are able to attack an even greater variety of trees than the ALB. Both these large beetles spend months deep inside trees as larvae and thus are very difficult to discover via inspections.


Of course, many of the pests being prevented by these new actions could, if established, travel on contaminated firewood. Here at Don’t Move Firewood we are excited that APHIS has begun applying their new NAPPRA authority to protect our forests. Exciting times!