340.2 (this list can be amended as outlined in part 340.5). In addition, a transgenic organism can be considered a regulated article if APHIS has reason to believe it presents a plant pest risk.
The definition of plant pest is in many ways extremely broad but in other ways surprisingly restricted. The breadth of the definition is provided by the inclusion of indirect injury or disease. Indirect injury occurs when a plant pest has an effect on another species that eventually leads to a detrimental effect on a plant. Thus, any species that interacts ecologically with a species that directly injures a plant (e.g., by feeding on it) can be considered a potential plant pest. Indeed, species that interact with species that interact with direct plant pests can be considered indirect plant pests, and this leads to the potential inclusion of nearly every species. In contrast, the taxonomic list restricts the definition of plant pest in an important way. According to the definitions, no vertebrate can be considered a plant pest, despite considerable evidence to the contrary. (This situation might change under the new Plant Protection Act of 2000; see Chapter 7.) For example, feral pigs and goats have had serious effects on native plants in Hawaii and other oceanic islands (Allen 2000). The exclusion also means that genetically engineered fish cannot be regulated as potential plant pests. There is some uncertainty about the status of algae as plants that could be affected by potential plant pests. Modern classification excludes most algae from the Kingdom Plantae (Campbell et al. 1997). Thus, many algae are not members of Plantae, as required by the definition of plant, but they are listed as a group under the definition. That is an important distinction because shellfish, which consume unicellular algae and are invertebrates, could be regulated under the APHIS rules if unicellular algae were considered members of the Kingdom Plantae.
Note that if a transgenic plant was created from a nonweedy species without the insertion of genes from a plant pest and it was transformed without the intervention of a plant pest (as would be the case with the use of particle bombardment or electroporation), it would not necessarily be considered a regulated article. In such cases, the creators of transgenic plants to be field released apparently have always sent a “courtesy” notification or permit application to APHIS, but the possibility remains that field release of certain transgenic plants could escape APHIS oversight.
Most transgenic plants are field tested under a notification system. In recent years “nearly 99% of all field tests, importations, and interstate movements of engineered plants [have been] performed under this sys-