Invasive plant ‘green cancer’ covers Big Island

HILO, Hawaii >> Hawaii officials have lost the war against an invasive South American plant, officials said.

The Hawaii Invasive Species Council has deemed the miconia as Hawaii’s worst invasive weed, the Hawaii Tribune-Herald reported Monday.

By the time officials knew about miconia, it had already spread, said Christy Martin, public information officer for Coordinating Group on Alien Pest Species. The plant is not going to be eradicated from the Big Island, she added.

“Our hope is to find biocontrols that are able to at least make the plant behave better,” Martin said.

Miconia is a large plant with purple and green leaves.

“The main thing is it can grow in such dense patches and create such a dark shade that it out-competes everything else,” said Tracy Johnson, a research entomologist with the U.S. Forest Service. “There’s nothing else that can grow underneath it.”

In Tahiti people call miconia “green cancer,” or “velvet cancer.” It has displaced more than two-thirds of native forest since being introduced in Tahiti in the 1930s.

The plant was introduced to Hawaii at a botanical garden in 1959.

“Even if you control the adult plants, the seed bank is just going to go on and on and on,” said Franny Kinslow Brewer, communications director for the Big Island Invasive Species Council.

An adult plant produces about 1 million seeds, which remain viable for 15 years.

Officials are currently hoping the Costa Rican butterfly can help control the plant, since as a caterpillar it feeds only on the leaves of plants like miconia.