The city is cutting down and removing Hawaiian wiliwili trees that have been ravaged by a tiny wasp.

The erythrina gall wasp appeared in the state last year and quickly invaded all of the islands.

Less than one-quarter the size of a mosquito, the gall wasp does not pose a threat to humans or animals but could destroy the native wiliwili tree population.

The insect's name comes from the ulcer-like distortions called galls on leaves, stems and shoots caused by the plant's reaction to larvae developing within its tissue.

The city has already removed dead wiliwili from Salt Lake District Park and Ke'ehi Lagoon Park.

Bill Brennan, city spokesman, said a cluster of trees was removed from Magic Island this week, and a dead wiliwili at the city's civic center grounds will be cut down today.

"We're trying to get ahead of the curve," Brennan said. "The bigger trees in the more heavily trafficked parks, once they're determined to be dead, we're trying to remove them."

He added: "The fear is that these dead trees are in danger of falling, and it's better to remove them and eliminate that danger."

Brennan said he wasn't sure how many trees in other city parks will need to be removed. But he said no wiliwili is safe from the wasp. The new species was first documented three years ago in Taiwan, and was first detected in Hawai'i in April 2005.

"It's everywhere. It's city trees, private land. The wiliwili tree population has really been devastated by this wasp," Brennan said.

"(The wiliwili) look real ghostly. They're very white looking. They have no leaves, no buds. But we're checking to see if they're really dead because if they do have some green buds on them then there's hope that maybe they're still alive."

Reach Curtis Lum at culum@honoluluadvertiser.com.