Atopomyrmex calpocalycola

The type material was collected from the "internodes of Calpocalyx sp.".

Identification
The worker of A. calpocalycolus is immediately separable from its two congeners by the presence of fully erect hairs on the mesosomal dorsum and the absence of dorsal spines on the petiole node.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun.

Nomenclature

 *  calpocalycola. Atopomyrmex calpocalycolus Snelling, R.R. 1992a: 96, figs. 1-5 (w.) CAMEROUN.

Worker
(mm): HL 1.01-1.74; HW 0.88-1.48; SL 0.49-0.71; PW 0.64-1.03; WL 1.06-2.00; TL 3.88-7.03. Indices: CI 85-87; SI 48-55.

Head distinctly longer than broad in all sizes. Mandible with well-separated fine punctures, interspaces nearly smooth to finely shagreened. Frontal carinae only slightly increasing in relative length and strength with increasing size. Antennal scrobes poorly defined in all worker sizes. Maximum eye diameter 0.14-0.27 mm, about 0.16-0.17 times head width. Antennal scape stout, ending only slightly above level of eye; flagellum 7-segmented, stoutly and evenly clavate, without differentiated apical club.

Outline of mesosoma as in Figs. Promesonotum curved, mesonotum without conspicuous lateral tubercles. Propodeal spines relatively short and thick; propodeal spiracle well basad of base of spine and not visible from above.

Node of petiole without dorsal teeth or spines.

Sculpture everywhere very fine; front of head with very fine, close striae and sparse, fine punctures, becoming smooth between punctures on gena and side of vertex. Dorsal surfaces of mesosoma, petiole, and postpetiole dull, densely shagreened and without other obvious sculpture; side of pronotum shiny and punctate below; side of propodeum with shiny, nearly smooth area of variable extent. Gastral terga moderately shiny between ultraminute, subcontiguous, piligerous punctures.

Smallest workers with sparse, erect brownish hairs across vertex and on side of head near dorsolateral corners, larger workers with only 2-4 hairs near dorsolateral corners; dorsum of mesosoma with sparse, erect and suberect golden brownish hairs of variable length; gaster similar along segment margins and on discs of most segments beyond tergum 1. Dorsum of mesosoma with abundant very fine, appressed pubescence; gastral terga with conspicuous appressed pubescence that partially obscures surface.

Color very dark reddish brown in mature specimens, clypeus and adjacent areas of face paler.

Type Material
Worker holotype and 26 paratypes from CAMEROON: Bayenti, north of Nguti, Southwest Province, 26 November 1989, collected by D. McKey from internodes of Calpocalyx sp. Holotype and most paratypes in Natural History Museum of Los Angeles County; paratypes also in Museum of Comparative Zoology and The Natural History Museum, London.

Etymology
The specific name is derived by combining the name of the host myrmecophyte, Calpocalyx, with the suffix –colus (living in).