LIHU‘E — Residents have until July 23 to comment on an Environmental Assessment concerning the release of a natural predator to control strawberry guava in Hawai‘i, according to a state Department of Land and Natural Resources news release. “It is
LIHU‘E — Residents have until July 23 to comment on an Environmental Assessment concerning the release of a natural predator to control strawberry guava in Hawai‘i, according to a state Department of Land and Natural Resources news release.
“It is our hope that people can look at the science and understand the gravity of the situation with forest and water at risk,” said Christy Martin, public information officer for CGAPS, in an e-mail. “Our only option is to get some help from nature.”
The revised draft is available under the Environmental Notice on the state Department of Health’s Office of Environmental Quality Control website.
“Biocontrol of Strawberry Guava by its Natural Control Agent for Preservation of Native Forests in the Hawaiian Islands,” authored by the Department of Agriculture, proposes to release in Hawai‘i a scale insect from Brazil, tectococcus ovatus, for biological control of strawberry guava, psidium cattleianum.
The insect is a highly specific natural control agent which produces leaf galls on strawberry guava that reduce the plants’ vigor and fruiting in Brazil, where both species are native, the revised draft EA states.
Strawberry guava was introduced to Hawai‘i from Brazil in 1825 and has become an invasive species that many people enjoy, consuming the fresh fruit, or using it in jams as well as using the wood to smoke meats, states the Hawaiian Invasive Species website.
However, its potential damage may outweigh its utility as it has no natural predators in Hawai‘i. This results in strawberry guava forming dense thickets replacing native Hawaiian plants and damages the watershed services that diverse forest provide.
In areas where strawberry guava has invaded native forests, there is a 27 to 53 percent reduction of water from soils, streams and groundwater systems, states a release from the Coordinating Group on Alien Pest Species.
“Strawberry guava is one of the greatest threats to our dwindling natives forests and the unique species that inhabit them, as well as our water resources and the traditional and contemporary uses and values these represent to the people of Hawai‘i,” said Deanna Spooner, executive director of the Hawai‘i Conservation Alliance, in an Office of Hawaiian Affairs release announcing a Big Island meeting to discuss the guava threat and biocontrol plan in April. The HCA, a partnership of state, federal and private land management agencies, voted to support the biocontrol plan in 2008.
Strawberry guava threatens local agriculture by supporting a large reservoir of fruit flies which damage produce and export potential, the CGAPS release states.
Thickets of strawberry guava also threaten cultural resources such as Hawaiian archeological sites and the plants and animals to which much of Hawaiian culture is tied.
“We have documented what is happening across many thousands of acres, and it is utterly clear that strawberry guava is among the worst invasive plants in the state,” said Dr. Gregory Asner, Department of Global Ecology, Carnegie Airborne Observatory, that has worked to aerially map what remains of native Hawaiian forests. Asner made this statement on the Hawaii Invasive Species website.
The EA states that introducing this control agent is expected to reduce growth and reproduction of strawberry guava, limiting its spread from areas currently invaded but not eliminating it.
Existing stands of strawberry guava will remain available for fruit picking and wood gathering, and control of existing thickets by current methods is expected to become more effective with the addition of biocontrol, according to the EA.
Health concerns
Sydney Ross Singer, a medical anthropologist with the Institute for the Study of Culturogenic Disease on the Big Island, is concerned about the health impact the release of the scale insect may have on the people of Hawai‘i.
“To our knowledge, research has never been done on the potential allergencity or other health impacts of human exposure to tectococcus ovatus — its eggs, waxy filament, chitinous material, crawling nymphs, winged males, and females,” Singer wrote in a letter to Dr. Chiyome Leinaala Fukino, director of the Department of Health, on the Save the Guava website. “Chitin is known to cause pulmonary inflammation and is highly allergenic. Inhalation of these tiny insects and their eggs and nymphs may induce sever allergic response.”
Protocol for biocontrol research and testing has improved vastly and cannot be compared to the careless and unregulated introduction of mongoose in the 1880s, states a report on the Hawai‘i Invasive Species website.
Since 1975, 51 biocontrol species have been introduced to Hawai‘i after thorough testing. Of these, none have switched hosts to non-target species and none have resulted in the eradication of its host, the report states.
The most recent success with biocontrol was the introduction of a wasp introduced to combat the erythrina gall wasp which was killing wiliwili trees throughout the state, threatening the existence of the tree.
Following 15 years of testing the biocontrol insect for strawberry guava, it has not killed strawberry guava plants, and has never attacked non-target plants of concern in Hawai‘i. These results were accepted by scientific panels administered by the Hawai‘i Department of Agriculture and a federal EA was conducted.
Following regulatory reviews and public comment, permits for the release of the insect were issued in April 2008 by the HDOA and the USDA Animal and Plant Health Inspection Service.
When some citizens indicated concerns about the draft EA, the agencies involved decided to gather more input through county and civic meetings, resulting in the revised draft EA which takes this additional feedback into account and is available for written public comment, states the OHA website.
“Even though public meetings are not legally required as part of the EA process, we felt it was important to take time to respond to concerns, improve the document, and allow additional opportunities for comment, said Tracy Johnson, a research entomologist with the U.S. Forest Service Pacific Southwest Research Station’s Institute of Pacific Islands Forestry, on the OHA website.
Written comments on the revised draft EA can be submitted to the Hawai‘i Department of Agriculture Plant Pest Control Branch at 1428 S. King St., Honolulu, HI 96814, with a copy sent to the DLNR, Division of Forestry and Wildlife, 1151 Punchbowl Street, Room 325, Honolulu, HI 96813.
E-mail “hdoa.ppc@hawaii.gov” for electronic comments.
Visit www.strawberryguavabiocontrol.org for a copy of the revised draft EA.
• Dennis Fujimoto, staff writer and photographer, can be reached at 245-3681 (ext. 253) or dfujimoto@kauaipubco.com.
