Acanthostichus femoralis

Mackay (1996) - Soil inhabiting species which preys on termites. Specimens have been found under cattle manure. One colony was found nesting in soil near the nest of Acromyrmex sp. (Kusnezov. 1962). Another series was collected with Pheidole sp. (Willink. per. comm.). Flights recorded during all months except Feb. Aug. and Oct. (Kusnezov. 1962). It is one of the few species which flies during the winter in Argentina.

Identification
A member of the brevicornis species complex. Mackay (1996) - The workers of this species can be separated from most others (except Acanthostichus sanchezorum) as the spiracle is located high on the propodeum. It could only be confused with A. sanchezorum, from which it can be distinguished as the outer surface of the scape is convex and it does not have an angle near the apex. as occurs in A. sanchezorum. The male of this species is easily distinguished from all others in that the petiole is nearly quadrate. but is strongly constricted on the two lateral surfaces. Otherwise it could be confused with Acanthostichus brevinodis or even with Acanthostichus fuscipennis. The single male was not associated with workers. but was labeled as A. femoralis. It seems reasonable that it is correctly identified. but must remain questionable until we have a complete series.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil.

Nomenclature

 *  femoralis. Acanthostichus femoralis Kusnezov, 1962a: 126, figs. 2, 3 (w.) ARGENTINA. Mackay, 1996: 150 (m.).

Worker
Mackay (1996) - HL 0.69-0.91, HW 0.54-0.76, SL 0.30-0.34, SW 0.11-0.15, WL 0.80-1.30, FL 0.41-0.51, FW 0.19-0.34, PW 0.28-0.41, PL 0.31-0.45, SI 37-44, CI 78-84, PI 109-114, FI 152-220, SL/SW 2.25-2.67.

Lateral angles on clypeus poorly defined; anterior borders of scape convex; head elongate, concave at vertex; femora of all legs, especially posterior, strongly incrassate (Fig. 44); petiole elongate, strongly concave anteriorly (Fig. 22); ventral process poorly developed. Glossy and shining, light brown throughout, scattered erect hairs on all surfaces.

Male
Mackay (1996) - Similar to most other species, except petiole is nearly quadrate and strongly constricted on the sides.

Type Material
Mackay (1996) - Worker, ARGENTINA: Western Formosa State, Ingeniero Juarez train station [paratypes seen]. Holotype worker. # 10423 (IMLA) [not seen] and 41 cotype workers. #'s 10422. 10424. 10449 (IMLA) [6 seen]. 2 paratype workers (MCZC) [seen]. Rio Argentina. Formosa. viii - 1958 [listed as July in Kusnezov (1962)]. Ing. Juarez. Col. N. Kusnezov.

References based on Global Ant Biodiversity Informatics

 * Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
 * Kempf W. W. 1968. Miscellaneous studies on Neotropical ants. IV. (Hymenoptera, Formicidae). Studia Entomologica 11: 369-415.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Kusnezov N. 1962. El género Acanthostichus Mayr (Hymenoptera, Formicidae). Acta Zoologica Lilloana 18: 121-138.
 * MacKay W. P. 1996. A revision of the ant genus Acanthostichus (Hymenoptera: Formicidae). Sociobiology 27: 129-179