Acanthostichus punctiscapus

Acanthostichus are subterranean, predaceous ants and are infrequently collected. The type collection of A. punctiscapus was taken from a nest of Pogonomyrmex desertorum at a depth of 70 cm. A second collection was of two workers taken at a termite trap. Little is know about this species or the biology of any species in this genus.

Identification
Workers (MacKay 1996): This species is easily recognized and can be separated from others members of the genus by the densely punctate surfaces, especially of the scapes.

Distribution
United States. New Mexico (type collection) and Arizona (Pima Co., Tucson, foothills of Sta Catalina Mts. CASENT0173204). Mexico.

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Mexico.

Habitat
Only known from desert habitat: the type locality (NM) "Larrea tridentata (creosotebush) Chihauhuan Desert scrub" and (AZ) "50' from wash in disturbed desert."

Abundance
With only two collections of this subterranean species known it is difficult to assess its potential abundance. This ant may rare or rarely detected.

Biology
The type series was collected in a nest of Pogonomyrmex desertorum at a depth of 70 cm. Only part of the nest was collected and no queen was found.

Nomenclature

 *  punctiscapus. Acanthostichus punctiscapus Mackay, W.P., 1996: 160, figs. 12, 30, 31 (w.) U. S. A.

Worker
Mandible with tooth on median masticatory border, with larger apical angle; sides of head parallel, occiput somewhat concave; femur somewhat incrassate, concave ventrally; petiole strongly narrowed anteriorly, with large, ventrally directed tooth. Most of ant with distinct, dense, small punctures, including mandibles, scapes, head, dorsum of mesosoma, petiole and gaster.

Measurements: HL 0.83-0.86, HW 0.70-0.74, SL 0.39-0.40, WL 1.18-1.24, PW 0.39-0.40, PL 0.44-0.48, SI 45-48, CI 83-86, PI 113-123.

Queen
unknown

Male
unknown

Type Material
Holotype (MCZ) and 38 Paratypes (AMNH, BMNH, CACS, CWEM, EMAU, FMNH, FSCA, IMLA, INPA, LACM, MACN, MCSN, MCZ, MIZA, MZSP, UAIC, UNAM, USNM).

Type Locality
New Mexico, Dona Ana Co.: Jornada LTER [National Science Foundation Long Term Ecologicial Research] site, 45 Km NE Las Cruces, 1.6 Km W of College Ranch Headquarters, about 150 m south of Jornado Playa; 17 July 1985, D. Lightfoot and S. Van Vactor collectors.

Etymology
Morphology. The name is a reference to the densely punctate scapes.