Author: The Great Courses Staff
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The Earth’s largest species of bee, Megachile pluto, has been spotted for the first time in nearly 40 years, according to National Geographic. Once thought extinct, it measures up to an inch and a half long. The rediscovery of the species prompts a look at the value that bees give us and the environmental dangers they face.
Megachile pluto was discovered in 1859 by noted scientist Alfred Russel Wallace, thus earning it the nickname “Wallace’s giant bee.” After Wallace’s discovery, the bee wasn’t seen again for over a century, leading many to believe it had gone extinct. When it was seen again in 1981, it was found on three separate islands in Indonesia. Then it disappeared again until two specimens were sold online in 2018. Now it’s being photographed in its natural environment for the first—and possibly last—time. The elusive bee reminds us both of the ecological value bees provide and the dangers they face in a larger scale.
Making the Case for Bees
It’s common knowledge that bees make honey and pollinate flowers. Most schools teach children about bees in elementary school. However, bees’ roles in our world extend far beyond providing these two simple benefits.
“About one-third of the foods we eat rely to some extent on bees,” Dr. Donald E. Moore III, Ph.D., director of the Oregon Zoo, said. “All vegetables and fruits including almonds, tomatoes, broccoli, runner beans, apples, blueberries, peaches, oranges, and lots of other crops rely on bees.” Bees are major players in the system of animal pollinators that also includes butterflies, moths, beetles, flies, ants, and wasps. “Without animal pollinators, Earth’s flowering plants and ecosystems would not survive,” Dr. Moore said.
What financial impact do bees have? Dr. Moore, who is also a senior science advisor at the Smithsonian’s National Zoo and Conservation Biology Institute, said that economists estimate bees’ economic value at around $15 billion—and that’s just from pollination. Bees often only travel a few hundred yards in their quests for pollen and nectar, but the longest recorded journey by a honeybee is 10 kilometers, which is over six miles. Unfortunately, these short flights that bees are accustomed to play a part in their declining numbers.
Colony Collapse Disorder
Since the early 1800s, millions of acres of land that bees have pollinated and thrived in have been converted from lush, diverse, open areas of flowers and flowering plants to monocultures of grass in suburbs and monocultures of crops in rural farms. As we pave over natural lands of eclectic vegetation and narrow the scope of wildlife available to bees, they suffer from a phenomenon known as colony collapse disorder.
“Colony collapse disorder was first detected in 2006 in the United States,” Dr. Moore said. “Colony collapse happens when worker bees abandon their hives in large numbers, with the result that colonies cannot sustain themselves.” Three major factors contribute to colony collapse disorder. Let’s take a look.
The first factor in colony collapse disorder is the reduction in diversity of plants mentioned earlier. “Honeybees naturally tend toward a more generalist diet and love diversity of plant food sources,” Dr. Moore said. “Yet when we use bees commercially, we put millions of bees in a monoculture that is anything but generalist.”
Second, colony collapse can occur with the introduction of some disease that’s particularly stressful for the colony. In explaining this factor, Dr. Moore cites the troublesome Varroa mite. The Varroa mite, a bee-specific parasite, is the carrier of a disease called the Israeli acute paralysis virus (IAPV). IAPV causes shivering wings and darkened abdomens and thoraxes in bees, eventually leading to paralysis and death. These symptoms are detailed in a 2014 report published by the Department of Entomology and Plant Pathology at the University of Tennessee at Knoxville.
Third, environmental stressors like pesticides and other pollutants can lead to the collapse of bee colonies. A study by Harvard University in 2014 definitively linked pesticides like neonicotinoids to colony collapse disorder. Unfortunately, neonicotinoids are used on most corn crops in the United States, and although bees don’t pollinate corn, they’re exposed to the chemicals as wind blows them to nearby bee colonies.
Clearly, the many species of bees perform a wide array of tasks that benefit humans. Yet they face ecological risks like colony collapse disorder that stem from man-made causes like pesticides and a narrowing of their natural diets in commercial use. Unless we can reverse the dangers to bees, wondrous species like Megachile pluto might disappear—forever this time.
Dr. Donald E. Moore, III, Ph.D., contributed to this article.
Dr. Moore is the director of the Oregon Zoo, senior science advisor at the Smithsonian’s National Zoo and Conservation Biology Institute and a conservation biologist with nearly 40 years of experience in wildlife conservation, animal welfare, and zoo management.