Weed control in the Pacific

Funding: New Zealand Ministry of Foreign Affairs and Trade

The Weed Biocontrol group at Manaaki Whenua - Landcare Research (MWLR) is internationally acknowledged as a world leader in weed biocontrol research and practice. It is one of three partners in the Managing Invasive Species for Climate Change Adaptation in the Pacific programme (MISCCAP) which is funded by the New Zealand Ministry of Foreign Affairs and Trade.

Invasive alien plants are among the most important groups of invasive species aﬀecting both the socio-economic well-being of Paciﬁc people and the islands’ unique ecosystems. Invasive species make ecosystems and communities more vulnerable to natural disasters and the impacts of climate change.

The 22 Pacific Island Countries and Territories include some of the smallest and most isolated countries in the world. Invasive plants contribute to reductions in biological diversity and can have significant economic impacts.

The only feasible method for controlling widespread invasive weeds involves using their own natural enemies against them. This approach has been safely and successfully used worldwide for more than a century.

Entomology technician Arnaud Cartier inspecting the progress of African tulip trees' natural enemies in the Inertebrate Containment Facility in Lincoln

In the Pacific, examples of weeds that have been successfully controlled through the use of natural enemies include broomweed (Sida spp.), giant sensitive plant (Mimosa diplotricha), grand balloon vine (Cardiospermum grandiflorum), lantana (Lantana camara), mile-a-minute (Mikania micrantha), water hyacinth (Pontaderia crassipes), water lettuce (Pistia stratiotes), and the African tulip tree (Spathodea campanulata)

Manaaki Whenua leads the Natural Enemies – Natural Solutions (NENS) programme of the SPREP led - Pacific Regional Invasive Species Management Support Service (PRISMSS). PRISMSS is supported funded via MISCCAP.

Have a look at the Battler’s Lounge – regular web-based seminars highlighting various projects around the Pacific.

The Cook Islands, Fiji, Marshall Islands, Niue, Samoa, Tonga, Tuvalu, and Vanuatu are all involved in NENS currently.