The reward for information on who’s destroying Hawaii’s papaya crops has grown from $2,500 to $5,000 and now to $10,000 — while papaya farmers wonder what’s triggering the destruction and who’ll be hit next.

Lani and Jerry Barao have been patrolling their 8.9-acre papaya orchard at night in their pickup truck ever since someone decapitated 800 of their papaya trees last month, costing them $900 in weekly lost production on their farm in Kapoho in the Puna District of Hawaii island.

"I’m so scared," Lani said Monday. "I’m actually praying that we don’t see anybody chopping down our papayas, because I don’t know what we’d do."

She suspects that her genetically engineered "Rainbow" papayas were targeted by eco-terrorists because a package delivery driver saw an anti-genetically modified papaya sign in the area one week before the Baraos and two neighboring papaya farmers were hit simultaneously July 18 or 19.

"Whoever did this to us, I hope that they’re happy," Lani said. "I just hope that other farmers won’t have to go through the same thing as us."

The current spate of papaya vandalism began in May 2010 when a papaya grower in Mililani found 397 of his 500 trees cut down. A month later a Hawaii island farmer in Kapoho suffered a $100,000 loss when 8,500 of his trees were similarly destroyed.

Then last month the Baraos were among three farmers who lost thousands of papaya trees on 10 acres near Tangerine Acres makai of Pahoa.

"It’s hard," said Erlinda Bernardo, who found 3,000 decapitated trees on her papaya farm near the Baraos’. "We don’t have any proof, and no evidence."

Genetically modified papayas were developed in the mid-1990s in response to the ringspot virus that had wiped out papaya production on Oahu in the 1950s, forcing the papaya industry to develop on Hawaii island with its genetically engineered "SunUp" and "Rainbow" papayas.

While protests greeted the first genetically engineered papayas, the papaya industry grew to represent one of Hawaii’s agricultural "bright spots" by developing export markets to the West Coast, Canada and Japan, said Myrone Murakami, president of the Hawaii Farm Bureau Federation. Potential, new papaya markets are also being explored in China and South Korea, he said.

Asked whether he believes eco-terrorists are behind the rash of papaya destruction, Murakami said Monday, "It’s possible. It is possible. Pick your poison. It could be anything — bad blood between different farmers because someone said or did something."

There are "at least 30" theories circulating among Hawaii’s 173 papaya farmers about who — and what’s — behind the destruction of Hawaii’s papaya crop, said Delan "Rusty" Perry, vice president of the Hawaii Papaya Industry Association.

All of the theories "have an ounce of credibility," Perry said Monday. "The important thing is that we find the final answer."

The Hawaii Papaya Industry Association has increased its reward to $10,000 for anyone who provides a tip that leads to the arrest and prosecution of whoever is responsible for the crop damage.

Big Island police did not respond Monday to requests for information on the status of their investigation.

Perry is also president of the Volcano Isle Fruit Co., which grows papayas down the road from the three Hawaii island farms that were hit last month. Like other growers, Perry has been victimized by tourists pulling fruit from his trees and had some of his trees cut down a decade ago.

But the current run of vandalism seems to be the work of a coordinated group of people who don’t take anything, but leave behind damaged papaya trees and their fruit, said Kenneth Kamiya, the owner of Kamiya Gold Inc. in Hauula, who is a former president of the Hawaii Papaya Industry Association.

"Even though they’re just cutting the heads off of the trees, that’s still a lot of work," Kamiya said. "It’s not a small job. It would take three or four guys a whole day to go through there."

This year’s unusually wet winter hurt papaya production across the islands, and about 1,000 of Kamiya’s papaya trees died from root rot "because of too much water," he said. Production of his "Kamiya Gold" papayas is down 30 to 40 percent from last year.

Kamiya believes the 2010 Mililani papaya damage was the result of "pure vandalism — neighborhood kids playing samurai."

But he thinks the Hawaii island destruction runs deeper.

"My take on it is it’s more like a feud between farmers," Kamiya said. "Everybody’s been fairly short on papayas this year, but I don’t think it’s business. I think it’s more like someone did someone bad."

Kamiya donated $100 last year when the reward for information jumped to $5,000 from $2,500, but he has yet to pledge any amount toward the current $10,000 reward. "No one’s come forward," Kamiya said. "That tells me it’s within the culture and no one’s going to squeal. I seriously doubt we’ll get anything."

Wherever the investigation leads, Lani and Jerry Barao are left struggling to make up for the loss of their papaya sales, which were supposed to pay the tuition at the University of Hawaii-Manoa for their 19-year-old son, Jerry Jr., who wants to study electrical engineering.

"We were depending on that income," Lani said.

The Baraos have applied for a $25,000 loan to cover their replacement costs for the trees but have not been approved yet.

So with last month’s losses on the family farm, Jerry Jr. will now start his sophomore year at Honolulu Community College because of its cheaper costs, Lani said.

The Baraos also have two younger children — ages 8 and 14 — and already were struggling to keep up with costs. Then the vandals hit, choking the Baraos’ main source of revenue.

"With the economy so bad and everything," Lani said, "who would do this to us?"