- Megachile pluto, Wallace's giant bee
- 4.5 centimetre(s)
- Indonesia ()
The largest species of bee is the Wallace's giant bee (Megachile pluto), the females of which can measure a total length of 4.5 centimetres (1.7 inches) – including their large mandibles. The females' wingspan can be up to 6 centimetres (2.3 inches) across. The Wallace's giant bee occurs only in the Moluccas Islands of Indonesia and was first discovered in 1859 by naturalist Alfred Russell Wallace (UK) on the island of Bacan in the Moluccan archipelago.
No further specimen was recorded until February 1981, when two enormous females were spied by entomologist Dr Adam Messer (USA) on Halmahera, Indonesia. Dr Messer later collected some male specimens – the first ever documented by science – which, at no more than 2.4 centimetres (0.9 inches) long, are much smaller than the females.
In January 2019, with many fearing that the Wallace's giant bee could be extinct in the wild, a team of US and Australian scientists funded by Global Wildlife Conservation, sighted a single female specimen in her nest during a five-day expedition in the North Moluccas islands.
Photo credit: Clay Bolt; claybolt.com