Centromyrmex alfaroi

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Centromyrmex alfaroi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Centromyrmex
Species: C. alfaroi
Binomial name
Centromyrmex alfaroi
Emery, 1890

Centromyrmex alfaroi casent0010795 profile 1.jpg Centromyrmex alfaroi casent0010795 dorsal 1.jpg Specimen labels

The biology of C. alfaroi is unknown but these large ants are presumed to be entirely subterranean, and thus are rarely encountered. In 1988 S. Cover observed closed turrets projecting from clay soil in open sunlit ground surrounding the River Station at La Selva Biological Station. Excavation yielded workers and males, and Cover suggested the turrets were the result of a premating flight excavation. Males have been collected at blacklights.

Identification

A member of the brachycola species group.

Keys including this Species

Distribution

Kempf listed records for Costa Rica, northwestern Bolivia and central Brazil.

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil, Costa Rica (type locality), Ecuador, French Guiana.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

All of the species in the genus appear to be termitophagous and all are superbly adapted to this specialised predatory life style. Observations of some species have found them to be rather helpless when placed in an exposed, open situation. Weber described what happened when he found a worker “just beneath the soil surface under a thin cover of dead leaves”. The ant was “completely helpless when exposed to the daylight and writhed about when placed on the ground or in my palm. It made no attempt to run away, curling and uncurling without stinging, though it had a long, stout sting”. In other words, it seemed unable to walk when removed from its specialised habitat and placed on a surface where it could not use its specialised legs. If not discovered within a termite nest, individuals are occasionally found in the top soil or the root-mat below the leaf litter layer, where their short, powerful, spiny legs facilitate their movement. (Weber 1949, Bolton and Fisher 2008).

Castes

Worker

Queen

Male

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • alfaroi. Centromyrmex alfaroi Emery, 1890b: 40 (w.) COSTA RICA. Emery, 1906c: 115 (q.). [Also described as new by Emery, 1894k: 46.] See also: Kempf, 1967b: 404.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Kempf (1967) - According to the original description, this species is larger than Centromyrmex brachycola, smaller than Centromyrmex gigas (the total length given for the holotype, a single-spread measurement, is 7.75 mm). Head broader than long with the sides converging cephalad. Clypeus convex, with an elevated median tumulus on disc, without a median longitudinal impression. Metapleura striate. Thorax strongly compressed at mesoepinotal junction, the basal face of epinotum grading continuously into the declivous face. Legs comparatively short and stout. Metatarsus of hind legs much shorter than tibiae. Petiole rather short, anterior face straight and oblique, dorsum completely rounded. Color dark ferruginous.

Queen

Kempf (1967) - Total length 8.8 mm; head length 1.39 mm; head width 1.60 mm; maximum diameter of eyes 0.53 mm; thorax length 2.77 mm; hind tibiae length 0.99 nun; hind metatarsus length 0.53 mm. Mandibles smooth and shining, with sparse, minute punctulae; mandibular line prolonged foreward on sides as a shallow groove; basal half of chewing border distinctly denticulate, apical half forming a sharp cutting edge without noticeable teeth. Clypeus with the anterior border conspicuously convex, with a prominent median tumulus, on disc. Antennal scapes almost reaching occipital corners. Compound eyes very large. Mesial spur of middle tibiae short and inconspicuous, not projecting beyond apex of tibia; lateral spurs missing both on middle and hind tibiae. Extensor face of hind tibiae with a few spine-like setae on apical half. Petiole as shown in Figs. 1 and 2. Gastric constriction weak. Sternum I of gaster without a prominent and marginate tuberosity beneath petiolar insertion. Wings (only hind wings preserved) hyaline, venation brown.

References