Author
Iain Paterson
i.paterson@ru.ac.za
Rhodes University
Makhanda
Coauthors
Quentin Paynter, Bioeconomy Science Institute – Manaaki Whenua – Landcare Research Group, Auckland, New Zealand
Sonia Kenfack-Voukeng, Green Connexion, Yaounde, Cameroon
Jason Callander, Department of Primary Industries, Brisbane, Australia
Lynley Hayes, New Zealand Institute for Bioeconomy Science – Manaaki Whenua – Landcare Research Group, Auckland, New Zealand
Abstract
African tulip tree, Spathodea campanulata (Bignoniaceae), is one of the world’s worst invasive alien species. On many Pacific Islands, large, monospecific stands of the tree have replaced indigenous vegetation, reducing biodiversity and altering ecosystem function. Surveys for natural enemies were conducted in the indigenous distribution of West Africa. An Eriophyiidae galling mite, Colomerus spathodeae, which deforms the leaves and shoots, was the first agent released in 2017 in the Cook Islands. It is now widely established there and has also been established in Tonga and Vanuatu. The mite is approved for release in Samoa and Fiji and is being considered for release in Australia, and the Solomon Islands, but some testing on indigenous Bignoniaceae is required. Preliminary results indicate that the indigenous Bignoniaceae are unlikely to be threatened by the release of the agent in these countries. The leaf-feeding flea-beetle, Paradibolia coerulea, was released in the Cook Islands in 2021 and is widespread on Rarotonga, with promising damage recorded near the original release sites. The beetle is being mass-reared in Tonga and will be introduced to Fiji, Samoa and Vanuatu before the end of 2025. A stem and pod feeding moth, Sinomphisa junctilinealis (Crambidae) is being studied. Rearing of S. junctilinealis in quarantine has been challenging, but is the next most promising candidate based on its mode of damage, which would hopefully reduce seed set.
Keywords
Establishment
New agents
eriophyiid mites
flea-beetle
Highlights
Biocontrol agents for African tulip tree have established in Cook Islands
These biocontrol agents are being released elsewhere in the Pacific
New, pod attaching agents are under investigation