It’s almost invisible — just two millimeters long.
But the borer beetle does huge damage to coffee crops worldwide — at least $500 million a year. It burrows into coffee beans and eats them from the inside out. Pesticides used against it are highly toxic to humans and increasingly ineffective.
So what’s the solution? Use nature to fight nature, says NatureNet Fellow Daniel Karp.
Karp’s research — which he did as a doctoral student at Stanford University and was just published in the journal Ecology Letters — finds that leaving bits of native forest habitat for borer-eating birds near the coffee plantations can reduce borer infestations by 50 percent.
Reductions like that mean the difference between failure and survival for the 20 million families dependent on coffee production for a living.
Now, as a NatureNet Fellow, Karp wants to build on that research to help farmers of other crops capitalize on the benefits of pest-eaters — and the natural habitat they need to thrive.
“There’s growing evidence that leaving little bits of natural habitat around your farm can support predators of crop pests, especially in temperate countries,” says Karp.
“As a NatureNet Fellow, I want to help create some basic decision support tools that farmers anywhere could use to determine how much pest relief natural habitat could give them in any situation — and then get that information incorporated into land-use decisions.”
Karp, an ecologist whose research interests center on developing innovative methods for harmonizing agricultural production with conservation, conducted his borer beetle research in Costa Rica, where the beetle had first been spotted in 2000 and had swept through the country in five short years.
His inquiry was inspired by previous findings that showed patches of native forest left in Costa Rican farmland supported native bees that raised coffee yields up to 20 percent. Karp wondered: Could such forest fragments make a difference for birds and bats that eat coffee pests?
So he enclosed some six-foot tall coffee plants inside cages to prevent bats and birds from getting at them, while leaving others uncaged. The experiment showed that pest infestation almost doubled in the absence of birds — yielding $100-$300/hectare in benefits.
“For a family farm of 30 hectares, that yields $10,000 in yield prevention,” says Karp. “That’s quite a substantial amount, given that the average Costa Rican income is about $6,000.”
But Karp’s work wasn’t done. He had to find and analyze bird feces for borer DNA to make sure which species were actually eating the pests.
Farms with more forests around them, it turned out, had both higher numbers of these bird species and fewer pests than those farms with less forest cover.
And caged plants near forests had bigger increases in borer infestation than those far from forests.
Case closed on the benefits of nature. And those benefits could be far-reaching.
“The borer is a global issue — it’s in more than 50 coffee-producing countries, except in China, Nepal and Papua New Guinea,” says Karp. “In Hawaii, farmers are reporting up to 50 percent of their yield lost to this pest.”
But while coffee is an important crop economically, Karp wants to use his NatureNet Fellowship to extend the benefits of predators in controlling pests for food agriculture. Here’s his plan:
And he says the Fellows program is a great vehicle to carry out this work.
“The Fellows Program is one of the most flexible postdoctoral program I’ve seen — it will allow me to pursue any area that I see fit, instead of just signing up to work on a specific PI’s project,” says Karp.
“It’s also a really good opportunity to connect with Nature Conservancy scientists and other Fellows who might be really important in guiding some of this work.”
And the Conservancy’s focus on human well-being, he says, fits his evolving outlook about the best direction for conservation.
“I’ve realized that conservation is just not effective unless you are simultaneously working with local people and improving livelihoods,” Karp says. “While I’m still an ecologist, I view agriculture as a perfect conduit of addressing human well-being concerns, but doing it through an ecological lens.”