You might think the world’s biggest bee would be easy to find. But that’s not the case: Until recently, the last time anyone had reported seeing Wallace’s giant bee living in the wild was in 1981. That changed in January, when the rare bee was spotted on an island in Indonesia.
Wallace’s giant bee — Megachile pluto — towers over European honey bees. The female’s size has been recorded as at least an inch and a half long, with a tongue that’s nearly an inch long. Add to that a pair of gigantic mandibles, and it’s a bee like no other.
“It was absolutely breathtaking to see this ‘flying bulldog’ of an insect that we weren’t sure existed anymore, to have real proof right there in front of us in the wild,” said natural history photographer Clay Bolt, who was part of a small team that sought out Wallace’s giant bee.
The team found a female bee living in a termite nest on the side of a tree — the large bee’s preferred habitat. The female Wallace’s giant bees use resin and wood to create tunnels and cells in existing nests, carving out their own living space away from the termites.
“To actually see how beautiful and big the species is in life, to hear the sound of its giant wings thrumming as it flew past my head, was just incredible,” Bolt said.
About that sound: Touting their discovery, the team posted B-roll (!) video of Wallace’s giant bee flying around in a small enclosure, its wings sounding like a deep drone compared to the high-pitched buzz of honey bees.
It’s not unusual for the Wallace’s giant bee to go long periods without being seen by humans. It’s been observed only a handful of times since it was discovered in the 1850s by British naturalist Alfred Russel Wallace. When the bee was last rediscovered in 1981, it had been presumed extinct.
“I’ve been saying it’s thought to be extinct,” said professor Dave Goulson, who heads a bee lab at the University of Sussex. “I was happy to hear that’s not the case.”
The breakthrough find came on the final day of a five-day trip to Indonesia’s North Molucca islands. Bolt’s visit to Indonesia came as part of Global Wildlife Conservation’s Search for Lost Species program. Others on the trip included Princeton University entomologist Eli Wyman; Simon Robson, a biology professor at the University of Sydney in Australia; and Glen Chilton, a professor at Saint Mary’s University in Canada.
In addition to its Brobdingnagian size, Wallace’s giant bee sports unusually large mandibles, which are often compared to a stag beetle’s.
The bee’s mouthparts also include a large labrum; in the early 1980s, entomologist Adam Catton Messer described watching a female Wallace’s giant bee using its mandibles to scrape resin from a tree, and using its labrum and mandibles to roll the resin into a large ball — which it then carried as it flew back to its nest.
“Messer’s rediscovery gave us some insight, but we still know next to nothing about this extraordinary insect,” Wyman said, echoing the reaction of other experts after the bee was spotted anew.
In theory, Goulson said, the large mandibles are similar to mason bees, which use them to help form the balls of mud that shape their nests. But those apian relatives are nowhere near as imposing as Wallace’s giant bee, he added.
Messer found several of the bees living in mountainous terrain of three islands in the North Moluccas, near the Equator.
That remote location is a main reason Wallace’s bee has been seen so infrequently, said Goulson, who has written several books about bees. And now, he added, that sheer remoteness might help protect it from anyone seeking to get into the bee-poaching business and sell a rare specimen.
Bolt and Wyman say they want their discovery to draw attention to the bee — and to the need to protect it. The world’s largest bee faces potential risks that range from insect collectors to the loss of its habitat from palm oil operations and other activity.
“Despite an abundance of potential nesting sites, the bee appears to be rare,” Messer wrote of his rediscovery in the 1980s. “Local informants had never seen the bee prior to its rediscovery, although a specific folk epithet, o ofungu ma koana, ‘king bee,’ is based on it.”
As has been the case with other historic perceptions about bees, the king bee turned out to be a queen: the females are far larger than the males, which measure less than one inch in length.