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Chalicodoma pluto, Wallace's Giant Bee

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Chalicodoma pluto, Wallace's Giant Bee, was first found in 1858 when Alfred Russell Wallace described it as "a large black wasp-like insect, with immense jawes like a stage beetle." This was the first and last time the species was seen until 1981 when Adam Messer discovered a nest with six females within an active arboreal termite nest. Until that discovery the bee was presumed to be extinct due to logging pressures.

Wallace's Giant Bee deserves its title. The female has an impressive body length of 39 mm and a wingspan of 63 mm. The male is smaller by comparison, but still large for a bee with body lengths up to 23 mm. This species somewhat resembles bumble bees, except that the mandibles on the female Wallace's Giant are enormous. Females nest obligatorily with termites, specifically Microcerotermes ambionensis which is an arboreal species. The females will burrow into the termite nest and from horizontal entrance tunnels that open to a main tunnel. Nest's can be very large, the largest found to date had 157 brood cells and 25 live larvae. These bees collect tree resin to feed their developing young.

Wallace's Giant Bee is found only in Indonesia on the islands of Bacan, Tidore, and Halmahera. This eco-region is a tropical wet climate and consists mainly of lowland forests. This area has a very high rate of endemism, which is why it deserves attention from conservation organizations. The extent to which M. pluto is threatened is unknown. The most immediate threat to the world's largest bee is loss of resin sources from increased forestry. There is a continual threat from commercial logging, agriculture, and diamond mining. Remarkably, this region still has 80% of its forest still in tact, which bodes well for populations of Wallace's Giant Bee.


Dollin, A. 2001. The largest bee in the world. Aussie Bee online.

Messer, A.C. 1984. Calicodoma pluto: the world's largest bee rediscovred living communally in termite nests (Hymenoptera: Megachilidae) Journal of the Kansas Entomological Society 57(1): 165-168


Written by: Kathryn Gardner 2004

Updated: Eric Denemark 2008

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