A group of scientists and insect enthusiasts has rediscovered the world's largest bee while on an expedition on a remote Indonesian island.

Key points: The bee was last recorded in 1981 and before that in 1859

The bee was last recorded in 1981 and before that in 1859 It doesn't die after stinging, has a 6cm wingspan and giant pincers on its head

It doesn't die after stinging, has a 6cm wingspan and giant pincers on its head The team found the bee in a termite mound after searching for five days in a tropical forest

Dubbed "the flying bulldog", Wallace's giant bee (Megachile pluto) has a wingspan of a whopping six centimetres.

The giant bee has only been documented twice before: when it was first discovered by naturalist Alfred Russel Wallace in 1859, and then again in 1981.

With no sightings since, it was thought to be extinct.

While researching the bee's whereabouts, the University of Sydney's Simon Robson and his colleague Glen Chilton of Saint Mary's University in Canada heard of a US-based photographer and a young entomologist who were planning to go search for it.

The four insect detectives decided to pool their resources and expertise.

Early one morning in January they met in Jakarta, and scrambled for a connecting flight to the Moluccas Islands to try their luck.

The bee was named after the cofounder of natural selection, Alfred Russel Wallace, who first identified it to science. ( Supplied: Clay Bolt )

"It was basically four people who had a long-term interest in this bee just got together and said, 'let's spend the money, we're going to go see if we can find it'," Dr Robson said.

"We met, we found it, we had a fantastic time, it was great! It was one of the best holidays I've ever had!"

The group searched through forest on an island in north-east Indonesia for five days in stifling tropical heat, checking termite nest after termite nest for signs of the bee.

The female bees burrow their way into termite nests to lay their eggs, leaving behind a tell-tale hole big enough to squeeze through.

"We were in the forest and it was late in the afternoon, and we were wandering off for a late lunch and one of us spotted a termite mound," Dr Robson said.

"One of us climbed up the tree and the hole was lined with resin and that was very encouraging, and we finally got the torch in there and we could see the bee in there looking out at us."

From there, they put a plastic tube over the hole in the termite nest and coaxed the bee out with a blade of grass to be photographed before releasing it.

'We were very keen to get stung by it'

The team came across a bee in a termite nest after searching in tough conditions for five days. ( Supplied: Simon Robson )

The bee collects nectar to feed to its young, but doesn't produce honey like the European honeybee or some Australian natives.

And also unlike the European honeybee, it doesn't die after stinging, according to Dr Robson.

"This bee could probably sting you quite happily and then sting you again, it wouldn't kill it," he said.

"In fact, if we'd found more we were very keen to get stung by it to see how painful it was. But because we only found one we didn't want to annoy it and we didn't want to upset it."

Wallace's giant bee also has a large set of pincers called mandibles on its head, which Dr Robson said could probably "do a bit of damage".

Because the bee has only been seen a handful of times, scientists still don't know much about it.

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For instance, it's possible that it may be a primary pollinator for a particular tree species in the islands where it is found, said entomologist Tim Heard, who was not involved in the discovery.

"That's quite possible, but we don't know that. We don't really know what it pollinates or if the the plant that it pollinates has an obligate relationship to that bee," said Dr Heard, an Australian bee expert at the University of Sydney.

Regardless of its ecological niche, Dr Heard said it needed protection from threats such as deforestation for palm oil, which is rife throughout Indonesia.

"I think we have a responsiblity to preserve all life on this planet," he said.

"It being the biggest bee in the world, it's rare, and it was discovered by Wallace, who was a legend in his field — he discovered evolution via natural selection along with Darwin.

"The fact that it's such a spectacular species and is such an amazing product of evolution, we have an obligation to preserve it."

Dr Robson said he and his colleagues hoped the presence of the bee in the Moluccas Islands could become a flagship for environmental conservation and ecotourism in the region.

"Deforestation is the major threat to most things and that can sometimes come into [regions] very quickly," he said.

"We may be able to get this bee in the eyes of the public as something that's worth coming to see."