Number of tansy ragwort plants controlled annually

Each year all tansy ragwort plants in the watershed are controlled prior to seeding by pulled or inclusion in a biocontrol experiment. Tansy flea beetles were released in several locations that had very high densities of tansy plants. The beetles have been very successful in reducing number of plants. More sites will be included in the biocontrol experiment as more flea beetles become available.
View full-sized graph >
