The Environmental Risk Management Authority has approved an application to release a parasitic wasp to control a moth that attacks gum trees.
The moth, a gum-leaf skeletoniser from Australia, was first found at Mt Maunganui in 1992, but was eradicated several years later.
A second incursion was discovered in Auckland in 2001, and the insect has since spread into Waikato, Northland and the Bay of Plenty.
The moth's larvae feed on the leaves of eucalyptus trees and several ornamental species, causing significant damage. The larvae can also cause human skin irritations such as stinging, itching and welts.
ERMA has approved the wasp, Cotesia Urubae, to act as a biological control agent.
The forest research institute Scion, which made the application on behalf of the industry, says it hopes to release the wasp early next year.
There are almost 25,000 hectares of eucalypt forests in New Zealand.