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Species: Mycocepurus tardus   Weber, 1940 

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Taxonomic History (provided by Barry Bolton, 2022)

Mycocepurus tardus Weber, 1940b PDF: 416, fig. 13 (w.) PANAMA. Neotropic. Primary type information: Primary type material: 5 syntype workers. Primary type locality: Panama: Canal Zone, Barro Colorado I.,, and (N.A. Weber). Primary type depository: MCZC. AntCat AntWiki HOL

Taxonomic history

Status as species: Weber, 1941b PDF: 108; Kempf, 1963b PDF: 430 (redescription); Kempf, 1972b PDF: 147; Bolton, 1995b: 269; Mackay et al., 2004 PDF: 6; Bezděčková et al., 2015 PDF: 118.
// Distribution


  Geographic regions (According to curated Geolocale/Taxon lists):
    Americas: Costa Rica, Nicaragua, Panama
  Biogeographic regions (According to curated Bioregion/Taxon lists):

Distribution Notes:

Panama (type locality), Costa Rica, Nicaragua. Costa Rica: widespread in wet forest habitats, to 800m elevation.


Natural History:

In Costa Rica this species inhabits wet forested habitats throughout the country. I have collected specimens from Corcovado National Park, Manuel Antonio National Park, Hitoy Cerere Biological Reserve, the Volcan Barva transect at 500m, and at 800m elevation in the Pe–as Blancas Valley east of Monteverde.

At Manuel Antonio, in mature wet forest, I found a M. tardus nest and a Trachymyrmex nest in close proximity, within 5cm of each other in the red clay soil in the center of a trail. The Trachymyrmex had a larger, asymmetrical tumulus above ground and a 3-4cm diameter fungus nest 5cm deep. The M. tardus had a small turret of soil and a 1-2cm diameter fungus nest near the Trachymyrmex. At San Pedrillo in Corcovado National Park, in primary forest, I found M. tardus in numerous small nests in a clay path. 1-2cm diameter tumuli covered the entrance holes. At the 500m site of the Volcan Barva transect I found a worker beneath a stone in mature rainforest. My other collections have been from Winkler samples of sifted leaf litter from the forest floor.

Mycocepurus tardus appears to be a form that favors forested habitats, while the very similar species M. smithii inhabits synanthropic habitats.

See also MacKay et al. (2004).


Kempf, W. W. 1963. A review of the ant genus Mycocepurus Forel, 1893 (Hymenoptera: Formicidae). Studia Entomologica 6:417-432.

Mackay, W. P., J. M. Maes, P. R. Fernandez, and G. Luna. 2004. The ants of North and Central America: the genus Mycocepurus (Hymenoptera : Formicidae). 7pp. Journal of Insect Science, 4:27, Available online:

Taxonomic Treatment (provided by Plazi)

Treatment Citation: Kempf, W. W., 1963, A review of the ant genus Mycocepurus Forel, 1893 (Hymenoptera: Formicidae)., Studia Entomologica (N. S.) 6, pp. 417-432

Mycocepurus tardus WeberHNS

Mycocepurus tardus WeberHNS, 1940: 416-417. fig. 13 (Worker; Panama Canal Zone: Rarro Colorado Island).

Worker (lectotype). - Total length 2.9 (3.1) mm; head length 0.68 (0.71) min; head width 0.64 (0.68) mm; scape length 0.56 (0.56.) mm; thorax length 0.88 (0.93) mm; hind femur length 0.67 (0.69) mm.. Reddish-brown; opaque.

Resembling quite closely smithiHNS in general habitus and sculpture, presenting the following differences: Occipital teeth quite prominent. Base of scape obliquely truncate in front of articular condyle, laterally and ventrally with a prominent carinule around base (incomplete ring). Promesonotum with a prominent pair of teeth in the middle of the circlet; infero-lateral tooth of pronotum small but distinct. Anterior pair of posterior mesonotal teeth practically absent, of epinotal teeth extremely low and blunt; connecting longitudinal carinules between posterior mesonotal and epinotal teeth absent or only vestigial. Clypeus and dorsum of scapes with erect hairs; tibiae and dorsum of gaster with curved not quite appressed hairs.

This species is known only from Barro Coliorado Island, Panama Canal Zone.

Specimens examined: Barro Colorado Island, Panama C. Z., June 12, 1938, N. A. Weber leg. n. 749, 1 worker (lectotype); same locality, N. A. Weber leg. June 1956, 1 worker (both in WWK received from NAW).

Discussion. - M. tardusHNS combines with the general fades of smithiHNS a few characters of goeldiiHNS (spinulation of premesonotal disc, pilosity of clypeus and scape), but seems for the time being sufficiently distinct from both. Weber (1940, fig. 13) gives a good lateral view of the thorax.

Note. - I have another worker from Barro Colorado Island (NAW n. 3805) which represents still another smithi-like variant, lacking completely the pair of anterior mid-pronotal teeth, a feature not observed in any other MycocepurusHNS specimen; its postpetiole is distinctly broader than long. Whether or not it is a still imdescribed species may not be decided for the time being.

Specimen Habitat Summary

Found most commonly in these habitats: 8 times found in mature wet forest, 5 times found in wet forest, 2 times found in rainforest, 2 times found in tropical wet forest, 1 times found in 2nd growth veg., stream edge, 1 times found in montane wet forest, 1 times found in Primary wet forest.

Found most commonly in these microhabitats: 12 times ex sifted leaf litter, 2 times nest in soil, 1 times nest in clay soil, 1 times under stone, 1 times Hojarasca, 1 times ground nest, 1 times ex sifted leaf litter on ground.

Collected most commonly using these methods: 4 times search, 8 times miniWinkler, 5 times Winkler, 1 times Mini Winkler.

Elevations: collected from 5 - 830 meters, 289 meters average

Collect Date Range: collected between 1982-01-01 and 2015-01-20

Type specimens:

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