WEDELIA (Sphagneticola trilobata) - DAISY INVADER OF THE PACIFIC ISLANDS: The Worst Weed in the Pacific?

R. R. Thaman The University of the South Pacific , Islands •Can a pretty daisy be compared with the likes of:

The Anopheles mosquito, the dreaded malaria vector? Brown Tree Snake (Boiga irregularis)

• That has brought birds and lizards in to extinction ?? Little Fire Ant (Wassmania aureopunctata)

That threatens endemic lizards and causes blindness in dogs in ?

I THINK SO!!!

“Wedelia”, creeping oxeye, or the trailing daisy, formerly known as Wedelia trilobata, but now Sphagneticola trilobata,

Is one of the world’s most aggressive weeds and listed among the world’s 1000 worst invasive alien species. Wedelia (Sphagneticola trilobata) • Native to tropical America from Mexico to Brazil and throughout the Caribbean

Now cultivated, firmly established and escaped from cultivation throughout the tropics and subtropics

Escaped and invasive on most of the main islands of , and . Wedelia (Sphagneticola trilobata)

•Escaped and out-of-control on:

The of , , and Tuamotus

The limestone islands of and Mangroves, Swamps and Wetlands

Buada Lagoon, Nauru

Rewa Delta Mangroves, Fiji

Marshland, Tikehau , Tuamotus Wedelia (Sphagneticola trilobata)

Has rampantly spread into: Out of Control on Atolls!! Houseyard, Atoll, Tokelau

Schoolyard,Houseyard, Fakaofo So. , Atoll, TokelauKiribati National Capitol, , Marshall Is

Lagoonside Lawn, Majuro Atoll Out of Control on Atolls!! Houseyard, Atafu Atoll, Tokelau

Houseyard, So. Tarawa, Kiribati National Capitol, Majuro, Marshall Is

Lagoonside Lawn, Majuro Atoll Coastlines and Beaches National Parks and Conservation Areas Sigatoka Sand Dunes National Park, Fiji Mountain Areas and Rivers Agricultural Areas

Fiji’ Sugarcane Belt

Palau, Women’s Agroforests Plantation Forests

Fiji’ Sugarcane Belt

Pine Forest, Moorea Nabou Pine Forest, Fiji Urban/Settled Areas

Fiji’ Sugarcane Belt Outcompetes Indigenous Species FINDINGS – CURRENT SITUAT

• Most attempts to control or eradicate it have failed, some at considerable cost. FINDINGS – CURRENT SITUAT

- It is suggested that wedelia should be immediately declared a serious noxious weed.

- Be restricted from introduction into new islands and habitats, and, where possible, eradicated from areas where it is yet to gain a foothold. FINDINGS – CURRENT SITUAT

-If action is taken NOW, islands and communities throughout the Pacific can prevent the spread of wedelia BEFORE it replaces extensive areas of indigenous where it out-competes plants of considerable ecological and cultural importance

-This conclusion is based on my studies of wedelia over the past 30 years in most of the countries and territories of the Pacific. FINDINGS – CURRENT SITUAT

• It is suggested that wedelia should be immediately declared a serious noxious weed, be restricted from introduction into new islands and habitats, and, where possible, eradicated from areas where it is yet to gain a foothold. If action is taken NOW, islands and communities throughout the Pacific can prevent the spread of wedelia BEFORE it replaces extensive areas of indigenous where it out-competes plants of considerable ecological and cultural importance. This conclusion is based on my studies of wedelia over the past 30 years in most of the countries and territories of the Pacific.

Gardens and Plantations