Octostruma amrishi

Octostruma amrishi is a lowland to lower montane species. It occurs mostly in mature wet forest, less often in second growth forest. In the northern part of the range in Central America, where O. gymnogon does not occur, it extends into cloud forest to 1500 m. In southern Central America, where O. gymnogon occurs, it exhibits an elevationally parapatric distribution with O. gymnogon and is restricted to elevations below 600 m. Almost all collections are from Berlese and Winkler samples of sifted litter and rotten wood from the forest floor. Dealate queens and intercaste workers occasionally occur together with workers in litter samples. One collection was of foragers on clay soil in a rainforest. See additional comments under O. balzani.

Honduras to southern Peru and Amazonian Brazil.

Mandible with 8 teeth, tooth 1 a broad blunt lamella, strongly differentiated from tooth 2, teeth 2–5 acute, similar in shape, with denticles between them; teeth 5–8 forming an apical fork, with 5 and 8 large, 6 and 7 small partially confluent denticles (O. balzani complex); face lacking erect setae on posterolateral margins of head (present in O. balzani, O. megabalzani, and O. trithrix), a medial pair present on vertex margin (lacking in O. gymnogon); mesosomal dorsum usually lacking a pair of erect setae (present in O. balzani, O. megabalzani, and O. trithrix); metanotal groove usually not impressed in profile view (impressed in O. balzani, O. megabalzani). When sympatric with O. balzani, O. amrishi is often a lighter red brown.

A cryptic inhabitant of leaf litter and rotten wood on the forest floor, lowland wet forests of Central and northern South America.

Pyramica amrishi Makhan, 2007a PDF: 1, figs. 1, 2 (w.) SURINAM. Neotropic. AntCat AntWiki

Taxonomic history

Combination in Octostruma: Bolton et al., 2008 PDF: 62.Junior synonym of Octostruma balzani: Bolton et al., 2008 PDF: 62.Revived from synonymy: Longino, 2013b PDF: 15.Longino, 2013b PDF: 16 (q.).