Pheidole moerens

Nomenclature

Species: Pheidole moerens Wheeler, W.M. 1908

Usage: valid

Diagnostic description

Diagnosis of worker among Antkey species

Worker castes bimorphic. Head shape ovoid (minor workers) or subrectangular with posterolateral lobes (majors), but never triangular. Antenna 12-segmented. Antennal club 3-segmented. Antennal insertions at least partly covered by frontal lobes; not surrounded by a raised sharp-edged ridge. Frontal lobes do not obscure face outline between mandible and eye; relatively close together so that the posteromedian portion of the clypeus, where it projects between the frontal lobes, is at most only slightly broader than one of the lobes. Posterolateral corners of head unarmed, without spines. Mandibles triangular. Mesosoma with erect hairs. Pronotal spines absent. Propodeum armed with spines or teeth. Slope of mesosoma steep. Waist 2-segmented. Petiole pedunculate with a distinct and upright node; lacking large subpetiolar process. Postpetiole attached to lower surface of gaster; not swollen; in dorsal view not distinctly broader than long or distinctly wider than petiole. Minor worker characters. Head punctate. Antennal scapes extend beyond posterior margin of head. Antennal scrobe lacking. Postpetiole not swollen relative to petiole. Hairs on mesosoma fine and flexuous, not arranged in pairs. Major worker characters. Antennal scrobe weakly to moderately impressed, but some depression capable of receiving antennal scapes clearly visible. Cephalic carinae terminating well before posterior head margin [requires additional analysis]. Posterolateral lobes distinctly rugose. Posterolateral portion of cephalic dorsum smooth and shining, lacking sculpture. Promesonotum in profile with one distinct convexity.

Minor workers of P. moerens are most easily distinguished from P. fervens, P. megacephala, P. obscurithorax and P. teneriffana by the presence of an entirely punctate head. Pheidole flavens can be separated from P. anastasii, P. bilimeki and P. punctatissima by the erect mesosomal hairs, which are fine, flexuous and not arranged in pairs (versus stout, stiff and arranged in pairs). Separating P. moerens from the closely P. flavens is very difficult, and additional character analysis is required before the two can be reliably distinguished from each other.

The rugose posterolateral lobes of P. moerens major workers separate them from P. megacephala (smooth and shining posterolateral lobes) and from P. anastasii, P. bilimeki and P. punctatissima (punctate posterolateral lobes). The presence of an antennal scrobe and the less densely packed rugoreticulum on the posterolateral lobes separate them from P. obscurithorax. They are separated from P. fervens and P. teneriffana by the smooth (versus sculptured) posterolateral portion of the cephalic dorsum sculptured (best observed in profile), and also by the presence of one convexity (versus two convexities) on the promesonotum in profile. Although Wilson claimed the cephalic carinae of P. flavens approach the posterior head margin while those of P. moerens stop short of the posterior head margin, the character does not seem to hold true across all populations. Stefan Cover (pers. comm.) has suggested that the Florida populations of P. flavens and P. moerens are easily differentiated with the latter occupying a wide variety of habitats, including disturbed zones, and flavens occupying more shaded mesic habitats. He also suggested the Florida moerens may have a more flattened portion of the posterolateral lobes that is shinier with a less foveolate ground sculpture.

Look alikes

Pheidole flavens

Distribution

Click here for updated occurrence data and map on antmaps.org
Click here for updated occurrence data and map on GBIF.org

A major worker. Photo by ©Alexander L. Wild, alexanderwild.com	A major worker. Photo by ©Alexander L. Wild, alexanderwild.com
A minor worker. Photo by ©Alexander L. Wild, alexanderwild.com	Anterior view of head, adult worker. Posterior third of cephalic dorsum sculptured.
Close-up view of frontal carina, adult worker. Frontal lobes relatively close together so that the posteromedian portion of the clypeus, where it projects between the frontal lobes, is at most only slightly broader than one of the lobes.	Anterior view of head, adult worker. Head punctate.
Anterior view of head, adult worker. Posterolateral lobes with distinct rugae.	Close-up view of antennal scrobe, adult worker. Antennal scrobe weakly to moderately impressed, but some depression capable of receiving antennal scapes clearly visible.
Close-up view of head, adult worker. Cephalic carinae terminating well before posterior head margin.	Anterior view of head, adult worker. The posterolateral lobes distinctly rugose and the lack of a punctate ground sculpture gives the head a shiny appearance. Used in Antkey to separate the major workers of Pheidole fervens, Pheidole flavens, Pheidole moerens, Pheidole obscurior and Pheidole teneriffana from those of all other Pheidole species.
Anterior view of head, adult worker. This character state was used by Wilson (2003) to distinguish Pheidole moerens from Pheidole flavens. However, the character is ambiguous and variable, and may have been based upon examination of a limited amount of material.	Lateral view of head, adult worker. Posterolateral portion of cephalic dorsum smooth and shining.
Anterior view of head, adult worker. Used to distinguish the major worker of Pheidole fervens, Pheidole flavens, Pheidole moerens and Pheidole teneriffana from that of Pheidole obscurithorax. The last species lacks any depression capable of receiving any portion of the antennae.	Lateral view of thorax / mesosoma, adult worker. Hairs on mesosoma fine and flexuous, not arranged in pairs.
Lateral view of thorax / mesosoma, adult worker. The promesonotum is composed of one, not two, distinct convexities. Used in Antkey to separate Pheidole flavens and Pheidole moerens from Pheidole fervens and Pheidole teneriffana.	Lateral view of thorax / mesosoma, adult worker. Promesonotum composed of one distinct convexity.
Lateral view of thorax / mesosoma, adult worker. The hairs on the mesosoma are fine and flexuous, not arranged in pairs. Used in Antkey to separate Pheidole flavens and Pheidole moerens from Pheidole anastasii, Pheidole bilimeki and Pheidole punctatissima.