For Elsie Greco to know how bad Hawaii’s coffee berry borer infestation is all that she needs to do is to see the coffee fruit that surrounds the growing beans.

Usually, Greco, a University of Hawaii at Manoa researcher, said last week, she’ll only find one hole, like a belly button on the skin, left by a tiny beetle that’s bored itself into the fruit.

But at times since the beetle was found on Kona a couple of years ago, Greco said she’ll take samples from coffee plantations back to the lab. And there, she finds two, three, or four holes.

So many belly buttons are a bad sign.

“When you have a farm with that kind of damage, you know the population is high,” Greco said.

Greco has been cutting into a lot of coffee fruit lately, as researchers at the University of Hawaii and the U.S. Department of Agriculture try to resolve vexing questions about how to deal with an unwelcome new species that came to the state and quickly began to devastate Kona’s coffee crop.

The fact that Greco has to cut into the coffee fruit to find the beetles highlights one of the many challenges involved with figuring out how to kill them off.

“They’re hard to study or control. They live in the darned coffee cherries,” said Ken Grace, associate dean for research at the University of Hawaii at Manoa’s College of Tropical Agriculture and Human Resources. The “cherries” are the fruit around the beans.

Such research received a boost last month when the USDA, at the urging of Sen. Mazie Hirono and Rep. Tulsi Gabbard, agreed to provide $1 million, which amounts to the largest commitment of federal research dollars that have been aimed at the coffee berry borer. The money will allow for ramping up research and preparing farmers on other islands for the beetle, Grace said. That is on top of $250,000 that the state legislature approved last year for research for each of the 2013-2014 and 2014-2015 fiscal years, and an additional $300,000 this fiscal year for controlling and mitigating the infestation.

The investment hasn’t come sooner in part because the borer beetle isn’t a widespread problem in the United States. The islands are the only place in the country where coffee is grown, Grace said. It’s also a new problem that has caught Hawaii unprepared as the beetles appeared suddenly for reasons that no one seems capable of explaining.

But it’s become a major problem. In a letter seeking “urgent” funding assistance from USDA Secretary Tom Vilsack on April 12, Hirono wrote: “The coffee berry borer was first identified in Kona in late 2010; since that time, the insect has multiplied rapidly and the damage is so extensive that many farms cannot be commercially harvested.

“Abandoned coffee fields are a source of insect population increases so the situation keeps getting worse,” Hirono wrote. “We need to quickly get control of this situation to prevent the spread of this pest to other coffee producing areas on the islands of Kauai, Maui, Molokai, Kauai, and Oahu.”

The fact that Hawaii is dealing with a new pest is nothing new for a state that discovers about 17 new kinds of insects and weeds every year. “We’re the invasive species capitol of the world,” he said.

“We’re located in the middle of the Pacific, right between Asia and the Americas…You have a lot of commerce, military, a lot of tourists, and an environment with none of the natural enemies that might have helped keep them in check at home,” he said.

New Menace

When a new species arrives, it usually brings clues about how to deal with it.

Beauveria bassiana, a natural fungus, has been effective in killing the beetles in South America and in other places where there’s coffee and coffee berry borers. But since the beetles mainly stay inside the fruit, the question is how to get the fungus to the beetles.

The only way, Grace said, is to spray the fungus when female beetles leave the fruit to find other berries to bore into and lay eggs. The male beetles are like house-husbands. They stay inside.

Courtesy of Elsie Greco

University of Hawaii researcher Elsie Greco takes samples of coffee fruit.

The fungus tends to thrive at higher elevations, which is great in Colombia. But Hawaii coffee plantations stretch up mountainsides, Grace explained. The fungus doesn’t last as long at lower, warmer ends of farms, so that means figuring out when to spray, how much and at what intervals. Not only that, some Hawaii coffee plantations tend to be on steep hills, so a schedule that works on one farm might not work on another.

“Basically at the moment, we don’t have the data on the efficacy of the fungus,” Grace said.

So that’s what researchers like Greco are doing, spraying at different times and different amounts, waiting a few weeks, and then cutting into the fruit to see how many beetles they find.

There’s no single solution, Greco explains. Dealing with the infestation involves a number of methods, and it is limited by the economic realities of the coffee business.

It is critical, experts say, to clear the fields of any leftover coffee fruit after harvest, so the beetles have nowhere to thrive. But paying pickers to do that is expensive and finding pickers is difficult because in a profession where pay is generally dependent on bulk, picking through the leftovers isn’t as lucrative.

In Latin America, farmers sell damaged coffee beans to coffee manufacturers locally, Greco said. Coffee beans in fruit that does not develop fully doesn’t produce high-quality coffee. Larvae left by the beetles also feed on the coffee bean, undermining its quality.

Some have raised the idea of selling damaged coffee locally in Kona — while also maintaining a quarantine to keep beetles from spread to other parts of Hawaii that produce coffee. The idea could help to bring in money to pay pickers to clear the fields, Greco said. But many in Kona are strongly opposed to selling inferior coffee for fear of damaging its reputation.

As Kona Coffee’s website says, “Kona Coffee is gourmet coffee grown in only one place in the world.”

(Courtesy of Elsie Greco)

University of Hawaii researcher Elsie Greco prepares a fungus mixture to spray on coffee plants.

So another part of the research is trying to make clearing the fields more cost-effective. But Hawaii’s sporadic rainfall is a problem, said Tracie Matsumoto, a USDA research horticulturist in Hilo. Unlike other parts of the world, where there is a defined coffee season, in Hawaii harvest season can go year-round with no break to clear the fields.

On sections of large coffee plantations, Matsumoto has been spraying a natural plant hormone onto coffee plants. Mimicking the hormone that tells plants to bloom, she has been studying whether there is a way to simultaneously get coffee plants to flower and bear the coffee bean-bearing fruit in order to concentrate the growing season and leave time for clearing.

So far, the results have been promising, she said. They’ve been opening up about a week after being sprayed. The next test is to see how the coffee tastes.

“This is good and it’s going to have an impact,” Grace said of the new research funding. “But I have to manage expectations. This isn’t going to be easy.”

About the Author