Number of tansy ragwort plants controlled annually

TansyRagwortGraphMed
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 were so successful in reducing number of plants that as of 2014 the biocontrol plots had too few tansy ragwort plants to continue the experiment. In future, all plants within the plots will be pulled. 

View full-sized graph >