Departing passengers Barbara and Chuck Curry of Corvallis, Ore., surrendered a container of cut bananas from Kaua'i while Nancy and Jim Riley of San Diego gave up a baggie containing watermelon.

U.S. Department of Agriculture officers Dominic Salazar and Myrna Tuya, staffing the plant protection and quarantine checkpoint station at the entrance to the wiki wiki shuttle waiting area on the second floor of the intersland terminal, placed the fruit the visitors chose to discard into a basket half filled with apples, oranges and a package of green grapes.

"We were planning to have it for lunch," Barbara Curry said of the cut bananas. "We knew we couldn't take it on the plane but thought we could eat it before we left (from the overseas terminal) because the signs said they would inspect the carry-on baggage at the last gate."

The Rileys thought the watermelon would pass because it was cut and bagged. "It really doesn't bother me," Jim Riley said. "I understand it has to be done."

While the state manages incoming traffic of plants, fruits and animals, the responsibility for outgoing inspections is the responsibility of the USDA.

Because of Hawai'i's location and the presence of insects here not common to the Mainland, rules governing outgoing vegetables and fruits are stricter than in other states, said Ronald Chock, a USDA plant protection and quarantine supervisor.

"This is a federal quarantine site," Chock said, "because we have different species of fruit flies (melon, Oriental, Mediterranean, green coffee scale) here that are not established in other states."

Chock added that the Chinese rose beetle; cactus, bean pod, asiatic rice and bean butterfly borers; and a weevil found in mango seeds are among other insects found here that present threats to agricultural economies in California, Arizona, Texas and Florida. And although fruits such as oranges or apples may have originated in Mainland states, they will not be allowed out of Hawai'i once they are here.

In a 12-month period from September 2004 to September 2005, USDA intercepted 104,194 pieces of fruit, vegetables and plant materials at its six checkpoint stations at Honolulu International Airport. Statistics from past years were unavailable but Howard Baba, a USDA plant protection and quarantine supervisor with 30 years of experience at the airport, said the numbers are up.

"It's always an upswing, never less," Baba said. "Our's is a more intensive go-between system for the biggest port in the United States because of the pest risk. We get exotic stuff introduced here all the time that they don't have in the continental United States."

Bananas are by far the most common fruit given up to USDA officers at checkpoints. A total of 23,478 of them were recovered in the past year.

The fruits, vegetables and plants given up by departing passengers are bagged, dated and stored in screened cages in an open area at the 'ewa side of the airport, where the USDA's offices are. The fruits are allowed to ripen and are then tested for fruit flies.

"We find something in maybe one-quarter of what we get," Chock said.

When asked if insect presence poses a threat to humans if the fruit had been consumed earlier, Chock smiled and noted, "Extra protein. It's not harmful to humans, just the industry."

Failure to declare illegal agricultural items can result in delays and fines of $1,000 or more. In most cases, people stopped at airport checkpoints are unaware they are doing something wrong.

For example, which of these people will not clear the USDA checkpoint: the lady with a hibiscus flower in her hair, a woman carrying gardenia flowers, a man with an uncut pineapple and another man with uncut breadfruit in a bag. Hibiscus, as long as there is no soil on it, and the pineapple are OK; the gardenias and breadfruit are not.

Why? Pineapples are the only raw fruit permitted because it's too acidic for fruit flies, Baba said. Gardenias attract the green coffee scale among other insects, while hibiscus flowers don't.

Confrontations are rare, but the USDA wants to avoid taking items from anyone leaving the Islands, especially visitors.

"Some people get upset, so we're trying to educate the public to lessen any misunderstandings," Baba said. "At the security points, we always give them the option to go outside and eat what they have or give it up."

No exceptions are granted at checkpoints, according to Baba. The most common excuse is people saying they are diabetic and need the fruit.

USDA officers have encountered people who try to smuggle items such as sweet potato or bittermelon leaves, bean pods and leafy herbs with seeds on them.

"We've found cardboard boxes with false bottoms where people have tried to hide ethnic vegetables," Baba said. Another common trick is to hide illegal fruits or vegetables under frozen foods.

"It's an obvious attempt at smuggling because they know it's illegal," Baba said.

Baba also cautions visitors collecting shells here that officers have found empty African snail shells among the collections. The snail shell poses a threat, even if empty, because it might contain eggs, Baba said.

Most lei sold at the airport will pass security. Orchids, carnation and pikake leis are on the approved list but jade vines, kikania and mokihana are among those that will not be cleared.

What happens here is stricter but stops are becoming more common on the Mainland.

"You can't take fruit from California to Arizona and back for the same reason," Cynthia Caceres of Los Angeles said. "I don't know why people still pack fruits in bags when they go to the airport. There's enough signs around here that say you can't take fruit or vegetables out of Hawai'i."

The federal government spent $80 million to eradicate Mediterranean fruit flies in California, according to Baba.

"If California gets an infestation, Japan will not buy its fruit, so it can be devastating," he said.

what's allowed ... and what isn't

Reach Rod Ohira at rohira@honoluluadvertiser.com.