Hawaii is paradise for termites and researchers seeking better control methods
POSTED: 1:30 a.m. HST, Aug 30, 2010
LAST UPDATED: 3:14 a.m. HST, Aug 31, 2010
|This story has been corrected.|
When Ken Grace came to Hawaii for a job interview 20 years ago, a swarming termite landed on his shoulder. He thought it was an omen of good luck.
One has to excuse Grace's enthusiasm for the bug considered to be the homeowner's bane. He was interviewing for the post of director of the University of Hawaii's Termite Project. The program, one of the few in the country, has been at the forefront of termite research and control methods, helping thousands of businesses and homeowners battle the destructive critters.
The need for the Termite Project here in Hawaii is indisputable. The cost of preventing, controlling and repairing damage caused by just one of the three most threatening species in Hawaii has been conservatively estimated at more than $100 million. Termites continue to be the most damaging insect pest in the state, with the warm, humid climate creating the perfect environment for their spread.
"There's really no place here that is safe from termites. It's a termite paradise," Grace said.
Aside from countless homes, commercial buildings, fences and furniture damaged by termites, Grace has seen them eat through Tupperware and the rubbery gaskets on water mains.
"Basically, if it's soft enough for them to take a bite out of it, they'll take a bite out of it," he said. "They'll go amazing distances. I've been in warehouses in Pearl Harbor where they'll literally be tunneling 50 feet up the wall into the wood ceiling."
TERMITE TALK AT SEMINARSLearn more about termites at a free seminar at 6 p.m. Sept. 16 at McKinley Community School for Adults. Registration is required; call 594-0540 or visit mcsa.k12.hi.us. A second seminar will be held at 6:30 p.m. Sept. 22 at Windward Community College; call 235-7433 or visit ocet.wcc.hawaii.edu/free.
Just this month, managers of a 44-story apartment building in Honolulu announced it would pay to relocate residents for a week so the building can be treated for termites. The problem was blamed primarily on infested cabinetry installed in the 352 units when the high-rise was built two years ago.
A more typical problem could be observed at a 55-year-old home in Aina Haina inspected by Terminix, the pest control company. Investigator Jeff Kaneshiro was immediately able to find telltale signs of termites, such as "kick-out holes," small pin-size holes along the exterior baseboards that termites create to expel waste. "The termites cover them up so they look like spots, but you can poke them open and sometimes see their butts pop out," he said.
In the basement, Kaneshiro probed floorboards and structural supports, looking for crumpling beams and planks. He noticed one spot immediately where the wood was shredded, and a small cork bulletin board with a frame that appeared to be paper-thin. Peeling it open revealed a small swarm of yellowish "worker" termites that consume wood, along with a few brown "soldier" termites that protect the workers.
The owner, who was raised in the home, said her father had never bothered having the structure treated. "He didn't believe it would do any good," said the woman, who did not want to be identified to protect her privacy. "He said, 'My grandson will tear it down and rebuild.' But who has that kind of money these days?"
Kaneshiro said the recommended treatment of tenting and fumigation could cost as little as $2,000. "It's in surprisingly good shape for never having been treated," he said.
The inspector has seen ground termites tunnel from the dirt into an automatic garage door. "Although the door was opened and closed regularly, the tunnel stayed open," he said.
RESEARCHERS HAVE found eight varieties of termites in Hawaii, but only three are considered threats to homes and other structures. One variety, the drywood termite, spreads by flight, hoping to land in a humid, sheltered spot to start a colony that can grow to several hundred individuals. The other two, the Asian ground termite and Formosan ground termite, build huge underground colonies that can cover areas the size of a football field. They tunnel into structures from below.
All three species can fly, leading to the common misconception that the majority of termites in Hawaii are drywood termites. "If you see a swarm of termites around a light, 99 percent of them are ground termites," said Carlton Agena of Terminix. "That's because the colonies of ground termites are so big, up into the millions."
The Asian ground termite, a tropical species, is of particular interest now because it is relatively new to the islands, having first been discovered here about 12 years ago. Grace and his team of researchers have found some intriguing differences comparing it with the Formosan termite, which has been in Hawaii for more than a century and is common in subtropical regions.
"The Formosan termite, our 'local' termite, tends to dig big, straight tunnels," Grace said. "The Asian subterranean termite has smaller and much more branched tunnels. It kind of makes sense because in the tropics they're probably going to have food for them everywhere. ... The Formosan subterranean termite probably has to go a little farther to find food typically, so they tend to go farther in their tunneling."
"If we look toward improving things like baiting for termites, those behavior differences could wind up being important. It might allow us to fine-tune how we place the baits, for example, to make it work better."
Grace worked in construction and pest control for years before enrolling in college and graduate school to study entomology. Relatively little was known about termites then, primarily because they were being effectively controlled by a pesticide called chlordane. Within a few years, however, chlordane's long-term toxicity led to it being banned, opening up the field to new study.
Homeowners concerned about termites can consult local extermination companies, making sure they are approved by the state's Structural Pest Control Board. Grace's colleague Julian Yates sits on the board as an ex-officio member. Grace and Yates also give public seminars at various locations throughout the state.
There are a variety of control and extermination possibilities, each having advantages and drawbacks, Grace said. Fumigation and heat treatment, which involves tenting the building and pumping it full of chemicals or heating it to at least 140 degrees, kills termites in the home but does not prevent them from coming back. Using poisoned bait depends on consistent monitoring and accurate placement of bait stations.
Preventive measures include installing termite barriers, a special mesh that keeps the termites away from vulnerable areas in new construction. Another preventive measure, a basaltic rock gravel barrier built around the foundation of a home, was invented by Grace's predecessor at the Termite Project, Minoru Tamashiro. He found that gravel is just the right size and shape to keep termites out.
"I believe that until recently it was the top-earning patent for the University of Hawaii," Grace said.
PREVENTION» Eliminate conducive conditions for termite infestation, such as dirt piling up around walls, wood staircases or pillars. If you have a wooden fence that goes directly into the ground, make sure it is not connected to the home.
» Seal broken vents and screens in rooftops, windows and doors. This is especially important during swarming season, which is late spring to early summer in Hawaii.
» Do not mount outdoor lights, which attract termites, directly on a home.
» Termite barriers, ranging from fine-mesh screens to a basaltic gravel, can be employed in new construction.
» Termite barriers also may be feasible over cracks in a concrete foundation.
» Install removable baseboards to make inspection easier.
WHAT TO LOOK FOR» Little mud tunnels leading from the ground to the house. If the tunnels are on a concrete or cinder-block foundation, that is evidence that ground termites have found a path to wood in the home.
» Piles of sawdustlike pellets. This is fecal matter from drywood termites. Each insect produces about one pellet a day.
» Pin-size "kick-out" holes that appear to be filled in. Termites often enter a structure through cracks, but once they start eating, they drill outward to the surface to expel waste. They then fill them in again to keep out predators, such as ants.
» Bubbles in the paint job, an indication of termites or moisture in the wood, which would encourage termite colonization.
TREATMENT OPTIONS» Fumigation and heat treatments for whole structures.
» If termites are localized, spot treatment is possible by drilling holes in the wood and injecting chemicals. Infested furniture can be placed in a house that is being treated by tenting.
» Baiting is the method of fighting ground termites. Traps are set in spots around the foundation of the home.
Source: UH Termite Project; visit www2.hawaii.edu/~entomol
CORRECTIONSpeaking about a termite-prevention measure developed at the University of Hawaii, Ken Grace, director of the UH Termite Project, said, "I believe that until recently it was the top-earning patent for the University of Hawaii." The last line of his quote was cut off on Page D3. The online version has been updated.