Megachile pluto, also known as Wallace's giant bee, is a very large
bee. It is the largest known living bee species. It was believed to be extinct until rediscovery in 1981.
Females may reach a length of 38 mm (1.5 in), with a wingspan of 63.5 mm (2.5 in). Males only grow to about 23 mm (0.9 in) long. M. pluto is believed to be the largest living bee species.