8 October 2024, Tongatapu, Tonga - The African tulip tree (Spathodea campanulata) is recognised as one of the world’s 100 worst invasive alien species and ranks among the top 30 terrestrial invasive plants. Initially introduced to many Pacific islands as an ornamental plant, this fast-growing evergreen tree now poses a significant threat to island biodiversity. It infests rainforests, outcompetes native vegetation, and negatively impacts agricultural production.
Recently, 210 African tulip beetles (Paradibolia coerulea) arrived in Tonga to help control the invasive African tulip tree. As part of the Pacific Regional Invasive Species Management Support Service’s (PRISMSS) Natural Enemies - Natural Solutions (NENS) Programme, a team from Manaaki Whenua – Landcare Research (MWLR) delivered the beetles to Tonga’s Ministry of Agriculture, Food, and Forests (MAFF). These beetles will be mass-reared at the Vaini Research Station in Tongatapu before being released at various sites around Vava’u.
The PRISMSS NENS programme aims to lower the impact of widespread invasive plants. Led by MWLR, NENS reduces the vigour of widespread weeds through reuniting them with safe natural enemies from their original homeland. The NENS programme initiatives empowers Pacific communities by improving the health and well-being of all living things and ecosystems.
Programme lead for the PRISMSS NENS team that is spearheading natural enemy weed control work across the Pacific, Ms. Lynley Hayes says the beetles have been extensively tested to ensure no other plants are at risk from it and have already been deployed in the Cook Islands.
“These are leaf-mining beetles. Adult beetles eat holes in the leaves and their larva mine through them,” says Lynley. “The beetles have been approved for release in Tonga and will ramp up efforts to help reduce the spread and density of the African tulip tree.”
Tonga’s National invasive species co-ordinator Viliami Hakaumotu says the beetles will be released on Vava’u where another specialist enemy of the African tulip tree, a gall-forming mite (Colomerus spathodeae) was released in December 2023. “The mites and beetles will work together in areas where the weed is too widespread for management through conventional methods,” he says.
The African tulip tree, originally from West Africa, invades indigenous forests and arable land, reducing biodiversity and agricultural productivity. Both the beetle and mite were sourced from Ghana and developed with assistance from Rhodes University in South Africa.
The Secretariat of the Pacific Regional Environment Programme (SPREP) Invasive Species Adviser, Mr. David Moverley commented, “African tulip is a common problem across the Pacific and it is great to see these two helpful natural enemies being relocated to the Kingdom of Tonga.”
“Whilst the impacts of African tulip to productive land are more immediately obvious, the impacts on native biodiversity and ecosystems are often out of sight as they grow and spread in shady areas under the forest canopy. Many catchments in the Pacific are impacted by this species by displacing native plants and reducing catchment stability and resilience.”
This project is part of the Restoring Island Resilience Programme, administered by SPREP and funded by New Zealand’s Ministry of Foreign Affairs (MFAT) and the Global Environment Facility. The programme aims to better manage invasive species in the Pacific and enhance the resilience of Pacific communities to climate change.
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For more information or for interviews, please contact Lynley Hayes at [email protected]
About PRISMSS: The Pacific Regional Invasive Species Management Support Service (PRISMSS) is a coordinating mechanism designed to facilitate the scaling up of operational management of invasive species in the Pacific. PRISMSS brings together experts to provide support within the Pacific region with a focus on protection of indigenous biodiversity and ecosystem function. As a service provider, PRISMSS provides a comprehensive suite of support services in a cohesive, effective, efficient, and accessible manner to Pacific Island countries and territories.
For further information please contact Mr Nitish Narayan, PRISMSS Communications & Liaison Officer on [email protected]