To aficionados, the taste of high-quality chocolate can be a heavenly delight. That's not entirely surprising for a product born from the seeds of the Theobroma cacao tree, given that "Theobroma" translates to "food of the gods." But few realize the world's supply of chocolate depends on midges, tiny no-see-um flies that are the cacao flower's only known pollinators. What's more, a scarcity of midges, combined with a host of new plant diseases, could lead to major chocolate shortages within five to ten years.
Cacao cultivation is notoriously difficult: Less than five percent of the flowers on a typical tree are fertilized. Part of the problem is the scarcity of pollinating insects. A further challenge is the "marked asynchrony between the time of peak flower abundance and the peaking of midge populations," according to Allen Young, a zoologist at the Milwaukee Public Museum who's been researching chocolate production in Central America since the 1970s. As an antidote, Young suggested spreading piles of freshly-cut banana stems on the plantation soil to provide breeding sites for midges and to help the flies survive the several-month-long dry spells. This measure boosted pollination by 15 percent, yet Young was convinced there might be a better solution.
"It helps to view the problem from the pollinator's standpoint," he says. The natural habitat of midges lies in the shady, litter-strewn floor of the rainforest, not in the sun-baked, monocultural arrays typical of most cacao plantations. Moreover, Young's research had already shown that pollination works better in small farms that lie close to the rainforest. The next logical step would be to replace large plantations with intermittent stands of cacao trees inside the rainforest—a strategy now being tested in the Tirimbina Rainforest Center in Costa Rica.
Placing small cacao plots within the rainforest can eliminate the need for chemical fertilizers and pesticides, Young says, while making the trees less likely targets for blight. "We're trying a more natural approach that is similar to what the Mayan Indians did 2,000 years ago. It's an old idea that might have some merit."
More than 80 percent of the world's 250,000 flowering plants depend on animal pollinators, and roughly 15 to 30 percent of the food eaten throughout the world comes from plants pollinated by these creatures.