Acanthostichus truncatus

The type series was collected raiding an arboreal termite nest.

Identification
A member of the serratulus species complex. Mackay (1996) - This species is most closely related to Acanthostichus kirbyi, but shows some affinities to Acanthostichus serratulus. It is easily separated from both by the shape of the subpetiolar process. It further differs from A. kirbyi in that the dorsum of the petiole has well developed longitudinal troughs, and from A. serratulus in that the lateral clypeal teeth are well developed.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia.

Castes
Known only from the worker caste.

Nomenclature

 * . Acanthostichus truncatus Mackay, 1996: 170, fig. 26 (w.) COLOMBIA.
 * Type-material: holotype worker, 14 paratype workers.
 * Type-locality: holotype Colombia: Putumayo, Mocoa, Guzman, 26.iv.1977 (D. Jackson); paratypes with same data.
 * Type-depositories: MCZC (holotype); BMNH, ICNB, IMLT, INPA, LACM, MACN, MCZC, MIZA, MZSP, NHMB, USNM, WEMC (paratypes).
 * Status as species: Palacio, 2019: 586.
 * Distribution: Colombia.

Worker
HL 1.23-1.54, HW 1.05-1.30, SL 0.60-0.70, SW 0.24-0.29, EL 0.04-0.08, WL l.64-l.96, PW 0.45-0.58, PL 0.64-0.76, SI 45-49, CI 84-85, PI 133-142, SL/SW 2.43-2.53. Mandibles without teeth or denticles; anterior border of clypeus concave. with two well developed processes; sides of head nearly parallel, slightly narrower posteriorly; vertex slightly concave; eyes small; scape with anterior margin concave. angulate near apex; mesosoma as in other species; posterior face of propodeum concave; petiole elongate, slightly wider posteriorly, subpetiolar process well developed, truncated ventrally (Fig. 26), ventral border slightly concave in some specimens of series; gaster as in other species. Erect hairs on all surfaces, up to 0.25 mm in length; decumbent pubescence present on gaster, but very sparse.

Sculpture mostly smooth and shining. sides of mesosoma and petiole striolate. almost punctate, top of petiole lightly punctate with longitudinal, shallow depressions or troughs.

Color reddish brown.

Type Material
Holotype worker and 14 paratype workers (,, , , , , MCZC, , , , , ) [all seen], COLOMBIA. Putumayo, Mocoa, Guzman, 26-iv-1977, D. Jackson.

Etymology
From Latin, truncates, referring to the shape of the ventral process of the petiole.