Dracula Ants of the genus Adetomyrma are rare and primitive ants endemic to the island of Madagascar. First described in 1993, the genus did not attract much scientific attention until the discovery of an entire colony in 2001.

Otherwise nondescript ants, Dracula Ants are named after their unusual feeding habits; queens and workers practice a form of "nondestructive cannibalism", chewing holes into and feeding on the hemolymph (insect "blood") of the colony's own larvae. This behaviour is thought to represent a precursor to the social feeding behaviour typical of more derived ant species, which use their larvae to digest their food (with the larvae later regurgitating it for the adults—which are unable to digest their own food—to eat).

Dracula Ants are also notable for their seemingly ancestral morphology; unlike other ants, which have two or three joints between the thorax and abdomen, Adetomyrma species have just one. This single joint may indicate the Dracula Ant to be an evolutionary "missing link" between ants and wasps which have similar abdomens.

The colonies, the first of which was found in a rotting log, may contain as many as 10,000 workers, winged males and several wingless queens (unusual, as most ant queens are winged). The workers use venom to stun their prey which are brought back to the colony for the larvae to feed upon. The colour of the winged males, a darker orange than the workers, suggests they disperse by flying to other colonies before mating.

Larva hemolyph as a food source has been reported in one other genus (to which the Dracula Ant is not closely related), Leptanilla. However, in Leptanilla the larvae secrete hemolymph from special glands; no incision is necessary.

See also: List of ant genera (alphabetical)

External links

• Pictures of specimens from AntWeb (http://www.antweb.org/description.do?rank=genus&name=adetomyrma&project=madants)
• New York Times: A 'missing link' with grisly habit (http://fluid.stanford.edu/~mbrennan/interests/insects/vampire_ants.html)
• AntColony.org: Dracula Ants may be key evolutionary link (http://www.antcolony.org/news/adifferentkindofantfarm.htm)