LIHU‘E — Passers-by stroll leisurely along the sidewalk unaware that in the wiliwili trees growing in Nawiliwili Park are under attack from an invasion of tiny wasps that could possibly kill off the Hawai‘i tree mentioned in “The Kumulipo” ancient Hawaiian chant that tells the story of the Earth’s creation.
“Is this what it is?” a resident couple who were enjoying a morning stroll asked when they examined the galls that form in the younger sections of the stand of trees that flank the “Nawiliwili Park” sign.
According to a “New Pest Advisory” flier issued by the State of Hawai‘i Department of Agriculture, “The calls were induced by the plant as a reaction to wasp larvae developing within the plant tissue.”
In a phone conversation with Craig Kaneshige from the Dept. of Agriculture Plant Quarantine Station in Pua Loke, Kaneshige said that there is a stand of about eight or nine trees at the Lihu‘e Airport that have been confirmed as showing evidence of damage from the Erythrina Gall Wasp.
However, Kaneshige said they have not yet checked trees in the Nawiliwili, or other Lihu‘e areas.
A University of Hawai‘i graduate student first spotted, and collected leaves and stems of a coral tree, Erythrina variegata L., in Manoa, O‘ahu.
Adult wasps emerging from the galls on the suspected leaves and stems were tentatively identified as the Erythrina Gall Wasp, Quaddrastichus erythrinaie Kim, by the student, and later by the UH College of Tropical Agriculture and Human Resources.
The identification was later confirmed by J. La Salle of the commonwealth Scientific and Industrial Research Organization in Australia through photos.
Over the past few weeks, signs of the wasp invasion, most notably the galls on leaves and stems, have been noticed on native wiliwili trees on Kaua‘i, Maui, and the Kona side of the Big Island.
The wasp’s larvae infest wiliwili leaves, causing them to swell. In extreme cases, infected leaves bunch up to resemble small heads of cauliflower.
Heavily galled trees lose their vigor to the point where they may shed their leaves and die, said a report from The Associated Press released earlier this week.
Some members of the conservation and science community have started collecting seeds from the native wiliwili in case the ancient low dry-land forest tree is wiped out by the wasp.
The problem is so new that officials aren’t sure what to do, the AP report added.
Officials say the only immediate hope is that the gall wasp brought with it a companion parasite that might, given time, help keep the gall wasps in check.
A similar thing happened last year when a parasitic wasp emerged to help combat a white fly infestation.
Lloyd Loope, research scientist with the U.S. Geological Survey’s Haleakala Field Station on Maui, said there wasn’t much hope for that, however, since no such parasite has emerged in Taiwan and the wasp was spreading so rapidly.
