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Coffee borer takes a bite out of crop
BY CHELSEA JENSEN | WEST HAWAII TODAY
The coffee berry borer is taking a bite out of this year’s Kona coffee crop. How big a bite depends on whom you ask.
The larva is white, with a brown head and a length of 0.7–2.2 mm and a width of 0.2–0.6 mm. Females have two larvae stages and males only one. They have strong mandibles, and their larval phase lasts 10 to 26 days. The pupae are yellowish, with a length of 0.5–1.9 mm.
The adults are small black beetles. Females are 1.4–1.8 mm long. The males are smaller, 1.2–1.6 mm long. Female beetles can fly short distances; males have no wings. Females have four to six teeth in the frontal margin of the pronotum. H. hampei is confused sometimes with the false borer (H. obscurus or H. seriatus) and Xylosandrus (Scolytidae) , but these species do not enter the coffee bean endosperm.
The maturation of the insect (from egg to adult) lasts between 24 and 45 days, varying according to the weather. Usually, the female drills the berry through the central disc, although it can enter through the side walls if the fruit is dry. Two days after the access, the beetle lays 35–50 eggs, which produce 13 females for each male. The lifespan for females is 35–190 days and for males 40 days. The new insects mate inside the seed. Some females lay the eggs in the same coffee plant, others colonise new ones. The males never leave the fruit.
The same plant can host three to five generations of beetles. Up to a hundred beetles can be found in a single fruit. The insect is very sensitive to desiccation, and waits for the rains to leave the fruit. The most affected areas in the crops are the shady and moist ones.
Various coffee growers and two University of Hawaii College of Tropical Agriculture and Human Resources scientists this week estimated the beetle’s impact on the crop to be from as little as 5 to 10 percent all the way up to a complete loss for farmers. The majority estimated the crop loss will be between 20 and 25 percent, however, a more definitive answer will come in January or February.
“This is the first year we will be able to see how extensive the damage really is,” said Skip Bittenbender, with College of Tropical Agriculture and Human Resources’ Department of Tropical Plant and Soil Sciences, who said damage from the now-established pest will likely exceed last year’s. “Some places may have 100 percent infestation, some places may not have any. But, I’ve been hearing (estimates of) 25 percent damage, but it’s early in the season and it’s not over yet.”
The female coffee berry borer, which is about the size of a sesame seed, was first confirmed in the Kona area in fall 2010 and at one farm in the Ka’u area in May, said Elsie Burbano, with College of Tropical Agriculture and Human Resources’ Department of Plant and Environmental Protection Sciences. The pest destroys coffee when it burrows into the fruit and lives its life cycle within the seed, or bean, causing damage that makes the coffee relatively worthless.
Kona Coffee Farmers Association President Colehour Bondera said the pest will cause about a 20 percent loss of the coffee crop in Kona. He estimates the same loss at his own Honaunau coffee farm, Kanalani Ohana Farm.
“The reality is there is a lot of impact by the borer on a large percentage of the farmers,” he said. “From my interactions with people, even those who’ve tried to limit the impact, we are seeing losses between zero and 40 percent.”
The annual Kona crop, which includes about 630 area farms, totals about 3.3 million pounds of green coffee annually, said Bondera. The National Agricultural Statistics Survey estimates the crop was valued at $21.7 million in 2008-09.
Considering an estimated 25 percent overall loss because of the coffee berry borer, that could amount to a 2011 crop totaling just 2.47 million pounds of green coffee carrying a value of $16.27 million, according to an analysis of the above Kona coffee crop and federal data.
Brent Hight, general operations manager for Koa Coffee Plantation, said the processor is having to deduct a percentage from what it buys because of damage caused by the beetle. The processor has also hired staff to determine what percentage of the cherry is damaged, which he said can change from day to day and can range anywhere from zero percent to 100 percent.
Other coffee processors, including Greenwell Farms and Captain Cook Coffee Co., did not respond for comment.
Hight said processors are trying to work with growers experiencing coffee berry borer damage to provide information on how to best handle the situation before it becomes worse.
“It’s a problem and we’ve got to work together as a team,” he said. “It’s not going to leave, we’re going to have to learn with it.”
At Holualoa’s Sugai Kona Coffee, President Lee Sugai said the company’s 50-plus acres of coffee has seen some impact from the coffee berry borer, but not too much. He estimated Sugai’s losses from the pest will be about 5 to 10 percent.
However, that 5 to 10 percent damaged by the borer will be a total loss since the company is not able to sell it to processors, he said. Normally, the company sells off-grade cherry to processors.
“In past times we used to resell a lot of the floaters (damaged, overripe or deformed cherry) to other people, because it did have value for some people, but, for this batch, we can’t do that,” he said. “We are just destroying the coffee. This year is the first time we’ve ever burned coffee. We’ve never done this before and I feel sad about it.”
Despite the overall crop loss, Sugai and other farmers said plenty of summer rain means the remaining coffee cherry will carry a higher value because it will be a higher, fancier grade.
While it is likely Kona coffee farmers will continue to see crop damage caused by the coffee berry borer far into the future, Bittenbender said 2011 will probably be the worst for area farmers.
He attributed the positive future outlook to three educational strategies the university is promoting: field and mill sanitation, use of traps to kill the pest and the use of Beauveria bassiana, a naturally occurring fungus toxic to the coffee berry borer.
“It will take a while, but we’re hoping this year will be the worst,” he said. “From here on out, the borer will do less damage as more people work to manage and control coffee berry borer.”
