Hawaii officials want to deploy a wasp throughout the state to combat another type of wasp that threatens a species of native trees.
A biological control plan issued by the state Department of Agriculture and Department of Land & Natural Resources calls for the use of wasps named Aprostocetus nitens, The Maui News reported Monday.
No specific timing was planned for their release, which would supplement another species that is already protecting the wiliwili trees statewide.
The black and metallic green Aprostocetus nitens are related to the Eurytoma wasp that defend the trees from a third wasp species.
Swollen, tumor-like growths called galls left by Erythrina gall wasps damage and kill thousands of wiliwili, along with other types of trees, officials said.
The Eurytoma wasp, called “a gall wasp gladiator” by the U.S. Department of Agriculture, was first released in Hawaii in 2008 to destroy the galls in the native trees.
The release of Aprostocetus nitens is needed to provide another layer of defense against the galls, which deform leaves and interfere with the ability to take in water and light, eventually killing the wiliwili, state biologists said.
Mature Aprostocetus nitens would be released on infested trees, with the first inoculations focused on severe infestations, officials said.
Wiliwili in bloom are distinctly Hawaiian, with coral red and salmon-colored flowers. The red wiliwili seeds are valued among Native Hawaiians for making leis and other uses, the state report said.
“If nothing is done, wiliwili could continue to decline due to their inability to produce viable seed,” the report said.
A public comment period for the state Department of Agriculture draft environmental assessment will remain open until Jan. 22.