An international team of scientists and conservationists has announced the finding of what many consider to be the 'holy grail' of bee discoveries  Wallace's giant bee.

The bee (Megachile pluto) is the world's largest, with a wingspan more than six centimetres (2.5 inches). Despite its conspicuous size, the bee has been lost to science since 1981.

In January, a search team that set out to find and photograph Wallace's giant bee successfully rediscovered the species in the North Moluccas, an island group in Indonesia. The find resurrects hope that more of the region's forests still harbour this very rare species.

The female giant bee makes her nest in active arboreal termite mounds, using her large mandibles to collect sticky tree resin to line the nest and protect it from invading termites. In hot and humid conditions, and sometimes during torrential downpours, the team observed dozens of termite mounds over the course of the search.

It wasn't until the last day of a five-day stop in an area of interest that the team found a single female Wallace's giant bee living in an arboreal termites' nest in a tree about 2.5 metres off the ground.

The bee wasn't seen again until 1981, when entomologist Adam Messer rediscovered it on three Indonesian islands and was able to observe some of its behaviour, including how it uses its mandibles to gather resin and wood for its nests. Since then, other teams have looked for the bee, with no luck.