The Centre for Agriculture and Biosciences International (CABI) experts have updated authorities, as well as researchers from several universities, public and private institutions and organizations dedicated to studying invasive species in Ecuador, on their efforts to help find an effective biological control for the invasive blackberry (Rubus niveus) on the Galápagos Islands.

Dr. Marion Seier and Dr. Harry Evans told the second participatory workshop — held by the project partners the Charles Darwin Foundation (CDF) and the Galápagos National Park Directorate (GNPD) — that CABI, in partnership with CDF, GNPD and the Yunnan Academy of Forestry and Grassland, China (YAFG), is stepping up research on a range of rust pathogens which could have potential to be used as biological control agents against the invasive blackberry.

During the workshop, Dr. Rakan Zahawi, executive director of the CDF, stated that, “The most problematic plant species on the islands is blackberry. Introduced in 1968, blackberry is now seriously degrading the Scalesia forest in Galápagos.”

Rubus niveus has invaded the wetter parts of the larger islands (Santa Cruz, Isabela, San Cristobal, Floreana and Santiago) and it has been estimated that control on Santa Cruz island alone would cost $50 million.

Dense, spiny thickets of blackberry can grow up to 3 meters tall, affecting farmland and also preventing the unique native forest dominated by endemic “daisy” trees (species of the genus Scalesia) from regenerating.

At present, control of the invasive blackberry is a mixture of manual labor and herbicide application, but its fast growth and large seedbank make these methods expensive, labor intensive and not very successful. This has led to heavy and regular use of herbicides or land abandonment. The workshop heard that current methods of control are not sustainable in the long term and, thus, a safer and more environmentally friendly approach, such as biological control, needs to be part of the management strategy.

Danny Rueda, director of the GNPD, said, “The biggest challenge is to find a solution that includes a biological control agent for this invasive species.”

CABI, since 2015, has been searching for potential biocontrol agents from the Asian native range of the blackberry (India to China) to be assessed for potential introduction to the Galápagos Islands. CABI’s work has also aimed to define more precisely the exact origin of the individual species’ biotype introduced to Galápagos using genetic markers.

Once a suitable agent is found, it will undergo a rigorous safety testing to ensure that the biocontrol agent for blackberry poses no risk to native, nontarget species, or to related cultivated species, such as  the commercial Andean raspberry (Mora) on mainland Ecuador, as well as ornamental roses grown for export.

Dr. Seier said, “The genetic variety of the blackberry Rubus niveus present in Galápagos originates from southern China and we are increasing efforts in this particular area to search for a rust fungus specific to the invasive Galápagos blackberry.”

On the first day of the workshop, presentations highlighted the work done over the last eight years to document the damage the invasive blackberry causes to the endemic flora, such as Scalesia species, and fauna, such as the endangered little vermillion flycatcher (Pyrocephalus nanus).

“The Scalesia forest on Santa Cruz has been reduced to only 3% of its original distribution and every year we are losing about 5% of the current distribution to the blackberry,” said CDF ecologist Dr. Heinke Jäger.

On the second day of the workshop, participants went on a field trip to Los Gemelos, to witness firsthand the damage inflicted on the Scalesia forest, as well as the hard work the GNPD is carrying out there to protect the endemic Scalesia pedunculata.

On the last day of the workshop, presentations explained the protocols and regulations in place for the importation of a biological control agent to Ecuador and the Galápagos islands. There were also working groups to discuss alliances between institutions to support the initiative, strategies to communicate the project to stakeholders and the community and future monitoring of the impact of a biocontrol agent following its release: all fundamental to direct the next steps of the project.

Mauricio Zambrano, an official from the Agency for Regulation and Control of Plant and Animal Health (AGROCALIDAD), who travelled from Quito to attend the event, said, “These workshops allow public and private institutions to see the problems caused by the introduction of species that do not belong in this ecosystem. The blackberry really is a big problem, so I congratulate the CDF and GNPD who are constantly seeking funds to control this pest.”

The workshop was held with the support of the Fund for the Control of Invasive Species in Galápagos (FEIG) and the Fund for Sustainable Environmental Investment (FIAS) and also the Ministry of Environment, Water and Ecological Transition (MAATE) and the GNPD.

Additional information

The CDF for the Galápagos Islands published a press release in relation to this story, which can be read in full on their website.

Project page

GNPD and CDF are partnering with CABI to help protect the iconic Galápagos Islands from an invasive blackberry.

With ongoing funding from FEIG (Fondo para el control de las especies invasoras de Galápagos), a trust fund set up to manage invasive species problems in the archipelago, CABI is working to identify suitable biological control agents for the blackberry.

Find out more from the project page “Controlling the invasive blackberry on the Galápagos Islands.”