Megaponera

Megaponera analis is the sole species of the genus Megaponera. They are a strictly termite-eating (termitophagous) ponerine ant species widely distributed in Sub-Saharan Africa and most commonly known for their column-like raiding formation when attacking termite feeding sites. Their sophisticated raiding behaviour gave them the common name Matabele ant after the Matabele tribe, fierce warriors who overwhelmed various other tribes during the 1800s. At nearly 20 millimetres (0.79 in) in length, M. analis is one of the world's largest ants. Megaponera is a genus of ponerine ant first defined by Gustav Mayr in 1862 for Formica analis (Latreille, 1802), the sole species belonging to the genus to date. In 1994 William L. Brown, Jr. synonymised the genus under Pachycondyla even though he lacked phylogenetic justification, thereby changing the name from Megaponera foetens to Pachycondyla analis. In 2014 Schmidt and Shattuck revived Megaponera back to full genus status due to both molecular and morphological evidence. Since foetens was just a specific epithet incorrectly used throughout the literature the new name for the species as of June 2014 is Megaponera analis. Due to its very wide distribution throughout Africa, it is likely that there are many more subspecies of M. analis than those recognised at the moment – some of which may warrant elevation to full species status. The five currently recognised subspecies of M. analis are: The size of worker ants varies between 5–18 millimetres (0.20–0.71 in), with larger workers making up to 50 percent of the colony. Though it was often suggested that the larger ants also function as gamergates, they were never observed laying fertile eggs, a function solely reserved to the ergatoid queen. Even though M. analis is often referred to as dimorphic, with a major and minor caste, they actually exhibit polyphasic allometry in worker sizes. The variations among the ants are mostly in size and pubescence (with minors having less), although differences in the mandibles have also been observed, with minors having smoother mandibles compared to majors. Megaponera analis occurs throughout sub-Saharan Africa from 25° S to 12° N. Its nests are generally subterranean, up to 0.7 metres (2 ft 4 in) deep, and often located next to trees, rocks, or abandoned termite hills. While the nest itself may have more than one entrance, it comprises only one chamber in which the eggs, larvae, cocoons, and the queen are located. The raiding activity of M. analis focuses on dawn and dusk between 6:00–10:00 and 15:00–19:00, with approximately three to five raids occurring per day. There are also observations of a third raiding activity window during the night between 22:00–2:00, although this phase has been poorly studied. Megaponera analis raids focus solely on termites from the subfamily Macrotermitinae and generally consist of 200 to 500 ants. The general foraging pattern of M. analis starts with scout ants searching an area of approximately 50 m (160 ft) around the nest for termite foraging sites. This searching phase can last up to one hour, and if it is unsuccessful the scout returns to the nest by a circuitous route. If a scout ant finds a potential site, it will start to investigate it without getting into contact with the termites or entering the galleries, before returning by the quickest route to recruit its nestmates to conduct a raid. While the quickest route is often also the shortest, this is not always the case. Scouts have been observed to use deviations on open terrain (like paths) on which they can run twice as fast to reduce travel time on average by 35%.