Acanthostichus arizonensis

A. arizonensis is a Southwest US and Northwest Mexico species which has been found associated with termites. Workers have been collected from chambers found under stones that occurred at elevations ranging from 1070m to 1780m. Little else is known about this species or its biology.

Identification
A member of the brevicornis species complex. Workers (MacKay 1996): The densely punctate petiolar node will distinguish it from all other species in the genus except Acanthostichus punctiscapus. It can be separated from this latter species in that the scape is mostly smooth and glossy (not heavily punctate as in A. punctiscapus).

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

Biology
A. arizonensis has been found in grasslands at the Santa Rita Experimental Range. It occurs from 1070m to 1780m, reaching up to the oak-juniper association. Workers are often associated with termites, which may be their principal or exclusive prey (Mackay and Mackay, 2002).

Caste
Known only from the worker caste.

Nomenclature

 *  arizonensis. Acanthostichus arizonensis Mackay, W.P., 1996: 141, figs. 6, 17, 18 (w.) U. S. A.
 * Status as species: Mackay & Mackay, 2002: 40.

Worker
Mandible with tooth-like protuberance on medial masticatory border, which may be essentially worn away; lateral clypeal angles well formed; outer edge of scape convex: eye consisting of four or five poorly defined ommatidia; vertex concave; hind femora elongate, not incrassate; petiole slightly longer than broad, slightly wider posteriorly; subpetiolar process poorly defined. Sparse erect hairs (most less than 0.1 mm, some as long as 0.25 mm) scattered on all body surfaces. Mandibles, scape, head and mesosoma smooth and glossy, with scattered punctures. Dorsum of petiole and most terga of gaster with dense punctures.

Measurements: HL 0.94-0.95; HW 0.79-0.83; SL 0.43-0.44; SW 0.16; WL 1.28-1.32; PW 0.44-0.46; PL 0.46-0.48; FL 0.58-0.60; FW 0.25; SI 45-46; CI 84-87; PI 103-106; FI 2.30-2.40; SL/SW 2.62-2.69;

Etymology
Geographic. "Indicates that this species occurs in Arizona."