It’s been 38 years since scientists last spotted the insect known as Wallace’s Giant Bee, a rare species found only in a group of Indonesian islands called the North Moluccas. With a wingspan of 2.5 inches and a body the size of a human thumb, it’s considered the world’s largest bee, and was feared extinct.
Those fears can now be somewhat laid to rest. In January, an international team of conservationists found a Megachile pluto, as the species is called, in the wild. The team captured the first-ever photos and videos of a live specimen, renewing hope for survival of the species, which is threatened by deforestation.
“It’s just ridiculously large and so exciting,” said Simon Robson, a biologist at the University of Sydney in Australia and a member of the expedition.
The discovery did not come easily. Despite the bee’s size, its rarity, remote location and nesting habits make it difficult to find.
“I personally know of at least five attempts to find the bee,” said Clay Bolt, a photographer who was part of the latest expedition.
The bees make their homes by digging holes in the nests of tree-dwelling termites, where they spend much of their time hiding.
“It was a lot of walking around the forest in 90-degree heat and the highest possible humidity looking at termite nests and chasing after bees,” said Dr. Robson. In all, it took five days of hunting for the team to find their “holy grail.”
Wallace’s Giant Bee is named after Alfred Russel Wallace, an English entomologist who worked with Charles Darwin to formulate the theory of evolution through natural selection. Wallace first discovered the bee on an expedition in 1859, describing the female as “a large black wasp-like insect with immense jaws like a stag beetle.” (The males are less than an inch long.)
Though Wallace didn’t seem particularly interested in the bee — he devoted only a single line to it in his journal — it became something of an obsession among biologists. The next sighting didn’t come until 1981, when Adam Messer, an entomologist, observed several in the wild and returned home with a handful of specimens that are now held in the American Museum of Natural History in New York, the Natural History Museum in London and other institutions.
Dr. Messer observed that the bees use their unusually large mandibles to scrape together balls of tree resin and wood to fortify their nests, and that they are relatively solitary animals.
Dr. Robson believes they are capable of stinging, though he wasn’t in a position to provide evidence. “We were all keen to get stung to see how bad it was,” he said, “but because we only found the one, we treated it very carefully.”
The expedition was partly funded by Global Wildlife Conservation, a Texas nonprofit that in 2017 started a global search for 25 “lost” species — animals that are not necessarily extinct but haven’t been spotted in at least a decade. In addition to Wallace’s Giant Bee, the list includes the Pink-Headed Duck, the Fernandina Galápagos Tortoise and the Namdapha Flying Squirrel.
Conservationists are concerned that deforestation threatens the survival of the bee giants. The region of Indonesia where the bees are found lost seven percent of its tree cover between 2001 and 2017, according to Global Forest Watch.
Excited as they were to find the bee, Dr. Robson and his team worry that the sighting may be a mixed blessing. Last year, an anonymous seller sold a previously unaccounted-for specimen to an unknown bidder on eBay for $9,100. “If you can get that much money for an insect, that encourages people to go and find them,” said Dr. Robson. To help protect the bees, the team has agreed not to disclose the exact island where they made their discovery.
The plan now is for the team to return to the island and conduct more extensive research, but “that will involve making links with local scientists in the area and getting permission to go and work with them,” said Dr. Robson.