Monday 27 April 2015

Bullet Ant



Paraponera clavata is a species of ant, commonly known as the bullet ant, named on account of its powerful and potent sting due to its venom. It inhabits humid lowlandrainforests from Nicaragua and the extreme east of Honduras south to Paraguay.


It is also known as the lesser giant hunting ant and conga ant. A local name is hormiga veinticuatro (the "24 ant" or "24-hour ant"), referring to the full day of pain that follows being stung. The specific epithet clavatameans "club-shaped".


Worker ants are 18–30 millimetres (0.7–1.2 in) long and resemble stout, reddish-black, wingless wasps. Paraponera ispredatory, and like all primitiveponeromorphs, does not displaypolymorphism in the worker caste; the queen ant is not much larger than the workers.





Paraponera clavata – museum specimen





Photograph demonstrating the size of bullet ants, with a 2-cm scale bar
Sting


The pain caused by this insect's sting is purported to be greater than that of any otherhymenopteran, and is ranked as the most painful according to the Schmidt sting pain index, given a "4+" rating, above the tarantula hawk wasp and, according to some victims, equal to being shot, hence the name of the insect. It is described as causing "waves of burning, throbbing, all-consuming pain that continues unabated for up to 24 hours". The ant is thought to have evolved its sting to ward off any predators that would normally unearth them. Poneratoxin, a paralyzingneurotoxic peptide isolated from the venom, affects voltage-dependent sodium ion channels and blocks the synaptic transmission in the central nervous system. It is being investigated for possible medical applications.
Initiation rites


The Satere-Mawe people of Brazil use intentional bullet ant stings as part of their initiation rites to become a warrior. The ants are first rendered unconscious by submerging them in a natural sedative, and then hundreds of them are woven into a glove made of leaves (which resembles a large oven mitt), stingers facing inward. When the ants regain consciousness, a boy slips the glove onto his hand. The goal of this initiation rite is to keep the glove on for a full 10 minutes. When finished, the boy's hand and part of his arm are temporarily paralyzed because of the ant venom, and he may shake uncontrollably for days. The only "protection" provided is a coating of charcoal on the hands, supposedly to confuse the ants and inhibit their stinging. To fully complete the initiation, however, the boys must go through the ordeal a total of 20 times over the course of several months or even years.


Colonies consist of several hundred individuals and are usually situated at the bases of trees. Workers forage arboreally in the area directly above the nest for smallarthropods and nectar, often as far as the upper canopy; little foraging occurs on the forest floor. Nectar, carried between themandibles, is the most common food taken back to the nest by foragers. Two studies in Costa Rica and on Barro Colorado Island(BCI) found about four bullet ant nests perhectare of forest. On BCI, the nests were found under 70 species of trees, six species of shrubs, two species of lianas and one species of palm. Nests were most common beneath the canopies of Faramea occidentalis and Trichilia tuberculata, but these trees are also the most abundant in the forest. Nests were present more frequently than would be expected based on the abundance of the trees under Alseis blackiana, Tabernaemontana arboreaVirola sebifera, Guaria guidonia and Oecocarpus mapoura. The large number of nest plants suggests little active selection of nest sites by bullet ants. Small shrubs, however, are underused, probably because they do not provide access to the forest canopy. The study on BCI concluded trees with buttresses and extrafloral nectaries may be selected for by bullet ants.






Source: http://en.m.wikipedia.org/wiki/Paraponera_clavata