Dracula ant (Adetomyrma venatrix)

Description

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Dracula ant fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Dracula ant description

The recently discovered dracula ant (Adetomyrma venatrix) is a highly unusual species, so named because of its grisly feeding habits of drinking the blood of its young ^{(2) (3)}. First described in 1994, these ants did not attract much scientific attention until the discovery of an entire colony in 2001 ⁽⁴⁾. The Dracula ant has since attracted widespread interest not only because of this curious behaviour, but also because of its seemingly ancestral morphology ^{(5) (6)}. Unlike most ants, these orange coloured ants have abdomens that closely resemble those of wasps, from which ants are believed to have descended some 70 to 80 million years ago ^{(2) (3)}. Thus, they have been described as a possible ‘missing link’ in ant evolution ⁽⁵⁾. Winged males are a darker orange than the workers, the queen is yellow and the larvae are white ^{(3) (4)}.

Dracula ant biology

Colonies of dracula ants may contain as many as 10,000 workers, winged males and several wingless queens ^{(4) (5)}. The workers go out each day to capture prey, which they stun using venom, to bring back to the colony for the larvae to feed upon. It is the unique and bizarre feeding habits of the queen and workers, however, which has fascinated researchers. Hungry Dracula ants scratch and chew holes into their larvae and suck out the hemolymph, the ant equivalent of blood ⁽⁴⁾. This practice has been described as a form of ‘non-destructive cannibalism’, since the larvae are not killed by it. Nevertheless, when hungry workers enter the chamber, the larvae have been observed attempting to flee and escape their fate ⁽⁶⁾.

Winged males are thought to disperse by flying to other colonies before mating ⁽⁴⁾. However, the colonies reproduce by budding (fission), with colony fission in ants being synonymous with short-range dispersal on foot because the queens are wingless. This has dramatic consequences on both gene flow and colonisation patterns and thus Dracula ants may be more susceptible to habitat disturbance ⁽⁸⁾.

Dracula ant range

The dracula ant is endemic to Madagascar ⁽¹⁾.

Dracula ant habitat

Dracula ant colonies have been found in rotting logs ⁽⁴⁾ and leaf litter ⁽³⁾ in tropical dry forest ⁽⁷⁾ in one of Madagascar’s last remaining high plateau forests just outside the country’s capital ⁽⁵⁾.

Dracula ant status

The dracula ant is classified as Critically Endangered (CR) on the IUCN Red List ⁽¹⁾.

Dracula ant threats

The precise threats facing this recently discovered species are unknown, but the dramatic growth of Madagascar’s human population and associated residential, agricultural and industrial development are known to be having a severe detrimental effect on the country’s forest habitat ⁽⁶⁾. Thus, habitat loss is likely to play an important role in the decline of the dracula ant, as it has with many of the island’s other endemic fauna.

Dracula ant conservation

Entomologist Dr. Fisher of the California Academy of Sciences, who first discovered an entire colony of dracula ants in 2001, has moved a few colonies into a laboratory environment ⁽⁶⁾. This not only allows the species to be studied in greater depth, but also serves as a buffer against total extinction. Indeed, it is feared that these relics of an earlier stage of evolution may disappear from the wild completely in less than a decade ⁽⁶⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For more information on the Dracula ant:

• Factbug.org:
  http://www.factbug.org/cgi-bin/a.cgi?a=557666
• Ward, P.S. (1994) Adetomyrma, an enigmatic new ant genus from Madagascar (Hymenoptera: Formicidae), and its implications for ant phylogeny. Systematic Entomology, 19: 159-175.
• Saux, C., Fisher, B. and Spicer, G.S. (2004) Dracula ant phylogeny as inferred by nuclear 28S rDNA sequences and implications for ant systematics (Hymenoptera: Formicidae: Amblyoponinae). Molecular Phylogenetics and Evolution, 33: 457-468.

Authentication

Authenticated (20/06/2006) by Dr. Brian Fisher, Entomologist at the California Academy of Sciences; expert on African and Malagasy ants; and AntWeb Project Leader.
http://www.antweb.org/

Glossary

Endemic

A species or taxonomic group that is only found in one limited geographic area.

Larvae

Stage in an animal’s lifecycle after it hatches from the egg. Larvae are typically very different in appearance to adults; they are able to feed and move around but usually are unable to reproduce.

References

1. IUCN Red List (May, 2006)
   http://www.redlist.org
2. USA Today (Society for the Advancement of Education). (2004) Picnic pests or ecological marvels? Ants—who have roamed the Earth since the days of the dinosaur—are expert farmers, fearsome warriors, voracious meat-eaters, and omnipresent socialites. Most of all, however, they are virtually indestructible. USA Today (Society for the Advancement of Education), 0.
3. Perlman, D. (2001) Discovery of Blood-Sucking Ant Species Scrambles Some Theories. San Francisco Chronicle, 2001. Available at:
   http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2001/01/15/MN138629.DTL
4. Factbug.org (March, 2006)
   http://www.factbug.org/cgi-bin/a.cgi?a=557666
5. Science Now (March, 2006)
   http://www.calacademy.org/science_now/archive/headline_science/dracula_ants.php
6. Everything2 (March, 2006)
   http://www.everything2.com/index.pl?node_id=1232501
7. The Ants (The University of North Carolina) (March, 2006)
   http://www.cs.unc.edu/~hedlund/dev/ants/GenusPages/Ponerinae/Genus9-long.html
8. Fisher, B. (2006) Pers. comm.