Biocontrol introduction
Target pest: Berberis darwinii (Ranunculales: Berberidaceae), Darwin's barberry
Agent introduced: Puccinia berberidis-darwinii (Pucciniales: Pucciniaceae), Darwin's barberry rust
Imported:
2019, 2022
Import notes:
Environment Canterbury (2025) - Berberis darwinii fruits with mature P. berberidis-darwinii pustules were collected from Valdivia, Chile and imported into containment in New Zealand in December 2019 and December 2022 for host range testing.
Landcare Research (2026a) - the development of P. berberidis-darwinii as a biocontrol agent has been a long and challenging process. It was first imported into containment in New Zealand as dried specimens from multiple sites across southern Chile in 2014 for molecular studies. The first importation of live rust was in June 2014, on detached leaves and on plants, but inoculations in containment did not result in infections. A breakthrough came in 2017 with the importation from Chile of rust-infected B. darwinii fruits, which proved to have many more spores than infected leaves. A small number of pustules formed from the infected fruit, just enough to maintain the culture in containment. Further imports of infected fruit were required to enable host range testing; shipping plant material proved unreliable but in 2019 around 1,000 hand-carried infected fruits from Valdivia in Chile allowed host range testing to begin. It was disrupted by Covid-19 travel restrictions and resumed only in 2022. EPA approval to release P. berberidis-darwinii was granted in July 2025 [see EPA (2025) entry in ‘EPA Applications’ section below] but the host range testing had reduced the amount of available rust in containment. Further infected hand-carried material was imported from Chile in December 2025 to provide sufficient rust for the first planned releases in September 2026.
Release details:
Landcare Research (2025g) - approval to release P. berberidis-darwinii was received in 2025; first releases are planned for spring 2025.
Landcare Research (2026a) - the first releases are now planned for September 2026 [see Landcare Research (2026a) entry in ‘Import notes’ section above].
Impacts on non-targets:
Environment Canterbury (2025) - host range testing was carried out in containment in New Zealand. There are no New Zealand native plants in the family Berberidaceae, to which Darwin’s barberry belongs. Thirteen non-target species, including two New Zealand native species, in the orders Berberidaceae, Ranunculaceae, Lardizabalaceae and Papaveraceae (all in the order Rununculales and the only families in this order present in New Zealand) were tested. Puccinia berberidis-darwinii infected and produced pustules exclusively on B. darwinii, indicating the rust does not pose a threat to New Zealand’s native plants.
EPA Applications:
EPA (2025) - 21 Feb 2025: application by Environment Canterbury to import and release a rust fungus, Puccinia berberidis-darwinii, and the flower weevil, Anthonomus kuscheli, as biological control agents for the weed Darwin’s barberry, Berberis darwinii. EPA Application # APP204814, approved without controls 17 Jul 2025.
References
EPA (2025). Application to EPA (APP204814) to import and release a rust fungus, Puccinia berberidis-darwinii, and the flower weevil, Anthonomus kuscheli, as biological control agents for the weed Darwin’s barberry, Berberis darwinii. Environmental Protection Authority website https://www.epa.govt.nz/database-search/hsno-application-register/view/APP204814/
Environment Canterbury (2025). Application to EPA (APP204814) to import and release a rust fungus, Puccinia berberidis-darwinii, and the flower weevil, Anthonomus kuscheli, as biological control agents for the weed Darwin’s barberry, Berberis darwinii. Environmental Protection Authority website https://www.epa.govt.nz/assets/FileAPI/hsno-ar/APP204814/APP204814-Application.pdf
Landcare Research (2025g). Who's who in biological control of weeds? Weed Biocontrol: What's New? August 2025, 113: 10-11 https://www.landcareresearch.co.nz/assets/Publications/Weed-biocontrol/Issue-113/weed-biocontrol-issue-113.pdf
Landcare Research (2026a). A rust for Darwin's barberry. Weed Biocontrol: What's New? February 2026, 115: 4 https://www.landcareresearch.co.nz/assets/Publications/Weed-biocontrol/Issue-115/weed-biocontrol-issue-115.pdf
