What was the first weed targeted for biological control in the United States?

The first weed targeted for biological control in the United States was alligatorweed. This plant, native to South America, became a significant nuisance in the U.S. because of its ability to rapidly grow and multiply in aquatic environments, where it can obstruct waterways and impact local ecosystems.

Biological control involves the use of natural enemies, such as insects or pathogens, to manage invasive plant species. In the case of alligatorweed, the introduction of specific biological control agents was aimed at reducing its populations and mitigating the negative effects it has on aquatic environments.

Water hyacinth, submersed weeds, and duckweed have also been problematic in aquatic systems, but they were not the first to be targeted for biological control efforts in the United States. The focus on alligatorweed marked the beginning of systematic biological control programs aimed at invasive aquatic weeds, paving the way for future efforts against other invasive species.