Acanthostichus concavinodis

Nothing is known about the biology of . The type material was collected as part of the Mulford Biological Expedition.

Identification
A member of the serratulus species complex. Mackay (1996) - This species is easily separated from all others in the species complex by the shape of the anterior face of the petiole, which is similar in form to species in the breviscapus species complex. In addition the carinae along the sides of the petiole are especially obvious, forming darker margins when viewed from above (Fig. 21). Other than the shape of the petiole, it has all of the characteristics of the serratulus species complex.

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Peru.

Castes
Known only from the worker caste.

Nomenclature

 * . Acanthostichus concavinodis Mackay, 1996: 147, fig. 21 (w.) BOLIVIA.
 * Type-material: holotype worker, 2 paratype workers.
 * Type-locality: holotype Bolivia: Ivon Beni, ii.1922, Mulford Biological Expd. (W.M. Mann); paratypes with same data.
 * Type-depositories: USNM (holotype); MZSP, WEMC (paratypes).
 * Status as species: Bezděčková, et al. 2015: 109.
 * Distribution: Bolivia, Peru.

Worker
HL 0.94-1.19, HW 0.85-1.10, SL 0.49-0.60, SW 0.18-0.21, EL 0.04-0.05, WL 1.19-1.41, PW 0.41-0.54, PL 0.43-0.49, SI 51-52, CI 93-110, PI 91-103, SL/SW 2.79-2.82.

Mandibles without teeth or denticles; anterior border of clypeus slightly indented, with blunt tooth or rounded swelling offset to one side or other, lateral clypeal teeth poorly developed; vertex moderately convex; sides of head nearly parallel; eyes tiny; scape concave on anterior border; mesosoma as in other species; propodeum with concave posterior face; petiolar node about as long as broad (measured from middle of anterior border and disregarding longer lateral margins), anterior petiolar face strongly concave (Fig. 21), posterior face as in other species, subpetiolar process as in other species, with posteriorly directed tooth; gaster as in other species. Erect hairs abundant on all surfaces; decumbent pubescence absent except for a few scattered decumbent hairs on gaster. Sculpture polished and shiny. Color clear golden reddish brown.

Type Material
Holotype worker and two paratype workers, BOLNIA: Ivon Beni, Wm. M. Mann, Feb. 1922.

Etymology
From Latin, concavus meaning curved inward, nodus referring to the node, describing the shape of the anterior face of the petiole.

References based on Global Ant Biodiversity Informatics

 * Bezdeckova K., P. Bedecka, and I. Machar. 2015. A checklist of the ants (Hymenoptera: Formicidae) of Peru. Zootaxa 4020 (1): 101–133.
 * Esteves F. A., C. R. F. Brandao, and L. P. Prado. 2011. The type specimens of Dorylomorph ants (Hymenoptera, Formicidae: Aenictinae, Ecitoninae, Cerapachyinae, Leptanilloidinae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulsos de Zoologia 51(22): 341-397.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * MacKay W. P. 1996. A revision of the ant genus Acanthostichus (Hymenoptera: Formicidae). Sociobiology 27: 129-179