Dracula Ants, or
Adetomyrma venatrix, are a newly discovered
species of
ant, found by
entomologist Dr.
Brian Fisher in
Madagascar. They are interesting because of the evolutionary link they show to
wasps, and their bizarre feeding behavior.
Ants are believed to have evolved from wasps, though the precise lineage is still unclear. While fossilized ants and those found trapped in amber have varying degrees of mandible similarity to wasps, until Adetomyrma none had the same body shape. Wasps have the rear section of their body (the gaster) connected to the middle section (the thorax) in a fashionable "wasp waist." Ants, on the other hand, have these two body sections connected by one or more segments, which give them greater flexibility in movement.
As for their feeding behavior, Adetomyrma are fairly different from other species of ants. Most colonies have a social sharing structure, where food is moved between different workers and the queen as needed. Others have worker ants who create what are known as alimentary eggs, which have more lipid content than regular eggs and cannot be fertilized. These eggs are stored in the queen's chamber and eaten as necessary. The feeding of Dracula ants differs from both of these systems. Dracula ants feed their larvae pre-digested food just like normal ants, but are themselves only capable of taking nourishment from ant hemolymph. To get this hemolymph (the ant equivalent of blood), they bite and scratch open the larvae and suck it out without killing them. Dr. Fisher has observed that when hungry workers enter the chamber, the larvae will actually run and try to escape from their fate.
Between Adetomyrma's waist, mandibles, and behavior, it shares characteristics of more than one subfamily of Formicidae (ants). This, combined with its possible close relation to wasps, makes it a true living fossil. Dracula ants were found, and probably only exist, in an area ninety miles outside of Madagascar's capital. Since Madagascar is going through dramatic growth and development, Dr. Fisher has moved a few entire colonies into a laboratory environment. He was quoted by Reuters as saying "Adetomyrma ... are relics of the earliest days of evolution, and if we don't collect some to study now, in another 10 years they'll be gone."