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