They filmed and photographed the creature, which is described as being four times larger than a European honeybee.
But it wasn't until the last day that the team found a single female Wallace's giant bee living in an arboreal termites' nest in a tree, about eight feet off the ground. That changed in January, when the rare bee was spotted on an island in Indonesia.
Currently, there is no legal protection addressing trade in the endangered Wallace's giant bee. The female's size has been recorded as at least an inch and a half long, with a tongue that's almost an inch long.
Despite its size, the bee remained elusive, with nearly nothing known about the female's secretive life cycle involving making nests of tree resin inside active arboreal termite mounds. He observed how the bee used its giant mandibles to gather resin and wood for its termite-proof nests.
'To actually see how handsome 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.
Wallace's giant bees, however, may not even last that long. The insect is named after British naturalist Alfred Russel Wallace, who formulated the theory of evolution by natural selection before Charles Darwin's published contributions.
Last month, Bolt and his colleagues embarked on a search for termite mounds in trees in Indonesia, the last place a scientist spotted the species. A solitary female bee was finally seen in the Indonesian province of North Maluku on the Maluku Islands, after researchers investigated the region for five days.
"Messer's rediscovery gave us some insight, but we still know next to nothing about this extraordinary insect", trip member and bee expert Eli Wyman, an entomologist at Princeton University, said.
The newly rediscovered Wallace's Giant Bee, also called "Raja ofu", or king of bees, has gained widespread media attention.
He said female bees appear to be "very docile", and that unlike social honeybees, they do not tend to sting.
The next time the bee was seen was 1981 when American entomologist Adam Messer reported sightings on three different Indonesian islands. It wasn't seen again for decades, making it the "holy grail" of 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.
None had been found alive until wildlife photographer Clay Bolt made public his finding of a solitary female of the species in February 2019. 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.
Prior to this discovery, the bee was thought to have become extinct as well before Messer found six nests on the island of Bacan and other nearby islands. "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".
Female specimens of the bee can reach a length of 3.8cm and have a wingspan of more than 6cm.