Natural enemies have been established on 25 weed species in 17 Pacific countries

Controlling invasive plants using natural enemies is a technique that has been used to manage weeds worldwide for over 100 years. Known as biological control, this was the topic of a five-day virtual training held for Pacific Island countries, with many now interested in making greater use of this method.

Invasive species are the leading driver of biodiversity loss in the Pacific, negatively impacting ecosystem resilience, ecosystem services, human health and the ability to adapt to climate change. Invasive weeds pose a threat to Pacific economies and ecosystems — be they the African tulip tree, Singapore daisy, lantana, or merremia vine.  

The virtual training highlighted how weeds can be and have been, successfully controlled in the Pacific using the biological control approach, and explored opportunities to further this work under the Natural Enemies Natural Solutions (NENS) programme.  NENS is a regional programme of the Pacific Regional Invasive Species Management Support Service (PRISMSS).

The range of topics covered over the five days included building understanding of the philosophy behind NENS, the six key steps involved in developing a NENS project and determining a prioritised work programme — given there are so many weeds. 

“In these days of mass social media, conspiracy theories, and widespread misinformation, it is crucial to listen to the science and be informed. This knowledge will be invaluable in helping you combat misinformation in your own countries, and within your own communities, and reassure those less-informed that the use of natural enemies, when used according to best practice, is both safe and a vital tool for the management of invasive plants,” said David Moverley, Invasives Species Adviser of the Secretariat of the Pacific Regional Environment Programme (SPREP). 

The workshop was hosted by the Pacific Invasives Battler Lounge of SPREP and delivered by Lynley Hayes, Quentin Paynter, and Temo Talie of New Zealand’s Manaaki Whenua-Landcare Research (the NENS Technical Lead for PRISMSS), and Michael Day of the Queensland Department of Agriculture and Fisheries. 

Natural enemies have been established on 25 weed species in 17 Pacific countries to date, with many opportunities to spread existing agents available in the Pacific to new countries and develop new options for the Pacific.

“In recent decades, weed biocontrol has become somewhat of a forgotten tool in the Pacific; however, the tide appears to be turning, with New Zealand enabling recent activity in the Cook Islands and Vanuatu, leading to the development of new agents for key weeds in the region,” said Lynley Hayes of Manaaki Whenua-Landcare Research New Zealand. 

“People have made bad choices in the past by introducing generalist species that are now widespread pests in the Pacific like myna birds, cane toads, giant African snail, and mongoose. However, these ill-considered introductions should never be compared with the use of specialist, carefully considered, safe natural enemies for weeds which have an excellent track record.”

This training was made possible through funding support provided by the New Zealand Ministry of Foreign Affairs and Trade (MFAT). NENS programmes are also being implemented in Niue, the Republic of the Marshall Islands, Tonga, and Tuvalu with support from the GEF6 Regional Invasives Project and the MFAT Managing Invasive Species for Climate Change Adaptation in the Pacific project.

The NENS virtual training was held from 16 to 19, and 23 March 2021. Over 60 participants attended from American Samoa, French Polynesia, Guam, Kiribati, Niue, Palau, Republic of the Marshall Islands, Solomon Islands, Samoa, Tonga, Tuvalu, Hawaii, Vanuatu, Fiji, and Wallis and Futuna.

All the training sessions are now available on the PRISMSS NENS Webpage or by joining the Pacific Invasives Battler’s Facebook Page

With funding now secured from New Zealand MFAT under the Managing Invasive Species for Climate Change Adaptation in the Pacific (MISCCAP) project, additional Pacific Islands will be able to tackle their most serious weeds with natural enemies.

The MISCCAP project acknowledges the significant contribution that invasive species management can provide towards enabling Pacific islanders to adapt to the impacts of climate change. 

PRISMSS is a collaboration of leading organisations that have a history of successes in supporting invasive species management in the Pacific, and Manaaki Whenua – Landcare Research is the lead PRISMSS technical partner for the NENS programme with a renowned role in controlling weeds using natural enemies in the Pacific. NENS is one of the five programmes of the PRISMSS. NENS reduces the impact of widespread weeds where the only safe, cost-effective, and sustainable way of managing is through utilising natural enemies (biocontrol). Further information can be found within the Battler Series “Use Natural Enemies to Manage Widespread Weeds in the Pacific”.

This workshop has been made possible with funding from the New Zealand MFAT as part of the Managing of Invasive Species for Climate Change Adaptation in the Pacific (MISCCAP) Project: a PRISMSS-NZ Collaboration for Pacific Resilience.