Biologists have long believed that orchid bees and orchids rely on each other in equal measure. The shimmering bees pollinate orchids in return for the flowers’ donation of perfumes, which male bees use to attract females. And so it was thought that the two organisms co-evolved. But a study led by Santiago Ramírez, an evolutionary biologist at the University of California, Berkeley, that was published in Science in late 2011 revealed that the bees arose first, thus suggesting that the two are more independent than previously thought.
Ramírez’s work shows that although the orchids seem very adapted to the bees—having developed scents that bees like and mechanisms to deposit pollen onto the bees’ body—the insects are far less specialized. They collect scents from more than 700 species of plants, and they pollinate an array of them. “The bees and plants all interact,” Ramírez says, “and we know very little about how those networks of interactions evolve.”
Learning more about the bees could help scientists understand their role in pollinating tropical orchids, many of which are in danger of extinction. The bees are in danger themselves, threatened by deforestation and land fragmentation in their native Central and South America, which has been wiping out the bees’ habitat and food sources. As a result, André Nemésio, a researcher at the Federal University of Uberlândia in Brazil who studies the elusive creatures, worries that scientists will not learn about the bees quickly enough to save them. “Orchid bees are solitary, very shy, and you almost never see them in the forest,” he says. Moreover, because no one knows exactly how important the bees are to the plants they pollinate or to their predators, the consequences of losing them present yet another mystery.
This article was published in print as "Busy Bee."