Plectroctena

Plectroctena is an Afrotropical genus of ants, with most species occurring in the rainforest zones of West and Central Africa.^[2] Some species are cryptic or subterranean foragers,^[2] while others forage in open grassland terrain. The workers forage singly^[3] or in groups of 2 to 3.^[4] They nest in the earth at varying depths, or in collapsed logs. They prey mainly on millipedes, including their young or eggs.^[2]

Plectroctena
Two workers in Tanzania
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Ponerinae
Tribe:	Ponerini
Genus:	Plectroctena F.Smith, 1858
Type species
Plectroctena mandibularis F.Smith, 1858
Diversity[1]
17 species
Synonyms
Cacopone Santschi, 1914

Plectroctena mandibularis

Colony structure

A colony of P. lygaria (a small species of the mandibularis-group) 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.^[2] The colony size of P. mandibularis however, seldom exceeds 50 individuals.^[2][3]

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.^[2] 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.^[3][2]

Diet

It is believed that millipede eggs may at times constitute the exclusive diet of P. lygaria,^[2] 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.^[2]

Species

• Plectroctena anops Bolton, 1974
• Plectroctena conjugata Santschi, 1914
• Plectroctena cristata Emery, 1899
• Plectroctena cryptica Bolton, 1974
• Plectroctena dentata Santschi, 1912
• Plectroctena gabonensis Santschi, 1919
• Plectroctena gestroi Menozzi, 1922
• Plectroctena hastifera (Santschi, 1914)
• Plectroctena laevior Stitz, 1924
• Plectroctena latinodis Santschi, 1924
• Plectroctena lygaria Bolton, Gotwald & Leroux, 1979
• Plectroctena macgeei Bolton, 1974
• Plectroctena mandibularis F.Smith, 1858
• Plectroctena minor Emery, 1892
• Plectroctena strigosa Emery, 1899
• Plectroctena subterranea Arnold, 1915
• Plectroctena thaui Fisher, 2006
• Plectroctena ugandensis Menozzi, 1933