Plectroctena
[image:Plectroctena mandibularis, werker, Tweeling, c.jpg|thumb|right|230px|Plectroctena mandibularis]
Plectroctena is an Afrotropical genus of ants, with most species occurring in the rainforest zones of West and Central Africa. Some species are cryptic or subterranean foragers, while others forage in open grassland terrain. The workers forage singly or in groups of 2 to 3. They nest in the earth at varying depths, or in collapsed logs. They prey mainly on millipedes, including their young or eggs.
Colony structure
A colony of P. lygaria may number in excess of 300 adults. An excavated colony in the Ivory Coast consisted of 277 workers, 8 alate queens, and 42 alate males. Consequently 15% of their number was allocated to reproductives at the specific time. The colony size of P. mandibularis however, seldom exceeds 50 individuals.
Nests
In a colony of P. lygaria, the nest chambers are located at shallow depth, in moist soil under dense leaf litter. The deepest chamber may be located about 7 cm below the surface, with each chamber up to 1 cm in height. The chambers are specialized to house either brood or prey items. Nests of the widespread species P. mandibularis however, are composed of chambers typically located 2 feet or more below the surface, with entrances that are usually marked by large piles of earth.
Diet
It is believed that millipede eggs may at times constitute the exclusive diet of P. lygaria, while newly emerged millipede young may be an additional food source for the smaller Plectroctena species. Larger species like P. conjugata, P. mandibularis and P. minor specialize on adult millipedes.
Species
Plectroctena anops Bolton, 1974Plectroctena conjugata Santschi, 1914Plectroctena cristata Emery, 1899Plectroctena cryptica Bolton, 1974Plectroctena dentata Santschi, 1912Plectroctena gabonensis Santschi, 1919Plectroctena gestroi Menozzi, 1922Plectroctena hastifera Plectroctena laevior Stitz, 1924Plectroctena latinodis Santschi, 1924Plectroctena lygaria Bolton, Gotwald & Leroux, 1979Plectroctena macgeei Bolton, 1974Plectroctena mandibularis F.Smith, 1858Plectroctena minor Emery, 1892Plectroctena strigosa Emery, 1899Plectroctena subterranea Arnold, 1915Plectroctena thaui Fisher, 2006Plectroctena ugandensis Menozzi, 1933