Acanthostichus brevicornis

This is the most commonly encountered species of Acanthostichus. It has been found under cow manure together with termites (Bruch, 1924) and is known to be a termite predator (Bruch, 1925). Mann (1916) found a small colony under a deeply imbedded stone.

Identification
Mackay (1996) - The workers of this species can be distinguished from others in that the femur is very broad, the petiole is subquadrate, usually with a strongly concave anterior face. It can be differentiated from Acanthostichus femoralis and Acanthostichus sanchezorum in that the propodeal spiracle is positioned at the midline, not above midline as in the other two species. It is similar to Acanthostichus kirbyi (and other related species, see discussion of A. kirbyi), from which it can be distinguished as the dorsum of the petiole is often punctate, with elongate depressions, the anterior face is not strongly thickened, the lateral clypeal teeth are poorly developed and the femur is not incrassate in A. kirbyi. The male can usually be distinguished from other species as it has an elongate petiole, is small and is without bluish reflections (see key).

Keys

 * Key to Acanthostichus workers
 * Key to Acanthostichus males

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, French Guiana, Guyana, Paraguay, Suriname.

Nomenclature



 *  brevicornis. Acanthostichus brevicornis Emery, 1894c: 142 (w.) FRENCH GUIANA. Mackay, 2004: 98 (q.). Senior synonym of ramosmexiae: Kusnezov, 1962a: 130; Mackay, 1996: 144.
 * ramosmexiae. Acanthostichus ramosmexiae Bruch, 1924b: 260, fig. (w.) ARGENTINA. Bruch, 1925a: 110 (m.l.). Junior synonym of brevicornis: Kusnezov, 1962a: 130; Mackay, 1996: 144.

Worker
Mackay (1996) - HL 0.74-0.96, HW 0.66-0.76, SL 0.31-0.38, WL 1.19-1.24, PW 0.35-0.40, PL 0.36-0.43, SI 39-42, CI 79-90, PI 100-106.

Mandible with only apical tooth developed; anterior medial border of clypeus concave, lateral clypeal teeth poorly developed; frontal carinae poorly developed, closely placed; head elongate, occipital border concave; petiole quadrate, anterior border strongly concave (Fig. 19), subpetiolar process a broadly rounded lobe (Fig. 20); femur flattened and incrassate (Fig. 43). Surface of body smooth and glossy (including scapes, dorsum of meso soma and dorsum of petiole).

Type Material
Mackay (1996) - FRENCH GUIANA: Cayenne [examined]. Calen [?] Jelski; Typus; Acanthostichus parallelus [? Word marked out] brevicornis Em; Typhlomyrmex serratula [label obviously incorrect]