Project overview
Darwin’s barberry is native to southern Chile and Argentina. It was introduced to New Zealand as an ornamental shrub and is now common from central North Island to Stewart Island. It invades farmland, forest margins, light gaps in disturbed or remnant forests, roadsides and scrubland, outcompeting native plants.
Two biological control agents, both weevils, have been approved for release against Darwin’s barberry in 2012. One destroys the flower buds (Anthonomus kuscheli) and the other damages the fruits and seeds (Berberidicola exaratus). The seed/fruit weevil was first released in 2015 and is now established at a number of sites in Southland and Wellington regions. The seed weevil has been released first and then the flower weevil if it is needed. It is hoped that by targeting the reproductive structures of the plant, these weevils will reduce the rate at which Darwin’s barberry is spreading.
A rust fungus (Puccinia berberidis-darwinii) that attacks Darwin’s barberry leaves and fruits has been imported into containment and is currently being studied to assess its specificity to Darwin’s barberry.
