Procryptocerus belti Forel 1899

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker lateral view

worker face view

Image catalogue, Costa Rican worker, automontage images (click here).

Image catalogue, Costa Rican workers, older images (click here).


Mexico to Panama, Ecuador. Costa Rica: abundant in the lowlands of the Pacific side, south of Puntarenas, rare elsewhere.

Description of worker

Worker measurements (n=1, Costa Rica): HW 0.991 (range 0.88-0.99, mean=0.93, n=12), HL 0.976, SL 0.645, EL 0.280, MeL 1.166, MeW 0.686, PrW 0.478, PrL 0.241, PrS 0.241, PrT 0.483, MTL 0.626, PtL 0.331, PtW 0.302, PpW 0.419, PtH 0.316, AL 1.179, AW 1.034.

Head subtriangular in outline, margin of vertex approximately straight; face with uniform areolate sculpture; frontal carina extends onto clypeus; separated from and passing above torulus as a differentiated carina; face to margin of vertex with regular honeycomb-like areolate sculpture; clypeus at level of antennal insertions abruptly bent ventrad; clypeus with prominent median carina, very faint longitudinal striae laterally; genae with closely-spaced foveae; genal bridge longitudinally striate; mandible granular, subopaque, with weak longitudinal striae; in anterior view, eyes asymmetrically convex, skewed ventrad; scape flattened with thick lateral margin distally, becoming narrower and more terete basally, then flaring into a basal flange; broad flat surface of scape finely areolate, outer lateral margin with coarse rugae; margin of vertex angulate but smooth, not crest-like or crenate; vertex largely smooth and shiny, with a few faint striae radiating from occiput.

Mesonotum convex, forming continuous curve with pronotum; in dorsal view, lateral lobes of mesonotum obsolete, visible at other angles as short, obtuse teeth; propodeal suture a broad, shallow trough; anterolateral propodeal lobes indistinct, small obtuse teeth a short distance posterior to anterolateral margin; promesonotum coarsely foveate anteriorly, becoming reticulate rugose on mesonotum (a specimen from Bugaba, Panama with posterior half of the mesonotum longitudinaly rugose, thus approaching hirsutus, but otherwise similar to typical Central American belti); irregular parallel longitudinal striae on dorsal face of propodeum, approximately 10 striae across at level of lateral lobes; posterior face of propodeum perpendicular to dorsal face, posterior face flat; posterior face of propodeum completely smooth and shining; parallel longitudinal striae cover lateral pronotum, anepisternum, katepisternum, and lateral propodeum; approximately 6 irregular striae on lateral pronotum, grading into foveae dorsally, and 1-2 on anepisternum, of similar size to those on pronotum; approximately 8 striae extend unbroken across katepisternum and lateral propodeum, these contrastingly smaller; posterior surface of forefemur entirely smooth and shining; outer surface of metatibia granular, with a few very faint rugae.

Ventral margin of petiole weakly concave, ending anteriorly in very small, obtuse tooth; anterodorsal face of petiole smooth and shiny; posterodorsal face coarsely foveate-rugose; postpetiole with flat anterodorsal face, short sloping posterior face; ventral margin of postpetiole short, with a prominent, acute anterior tooth; dorsum of postpetiole coarsely foveate-rugose; first gastral tergite densely and finely punctate throughout; first gastral sternite densely and finely punctate laterally and anteriorly, punctation fainter on disc; second gastral tergite with faint, dense, granular sculpture.

More than100 short stiff setae distributed uniformly on face; abundant stiff setae on mesosomal dorsum (more than 20 on central area of promesonotum, not including those on lateral margins), longer than those on face; setae on petiole and postpetiole abundant, longer than those on mesosomal dorsum; first gastral tergite with dense, long stiff setae, grading continuously from suberect to decumbent; color shining black, with legs and antennae contrastingly light orange-brown.

Description of queen

Queen measurements (n=1, Costa Rica): HW 0.92, HL 0.90, SL 0.60, EL 0.27, MeL 1.34, MeW 0.75, MTL 0.59, PtL 0.34, PtW 0.29, PpW 0.43, PtH 0.30, AL 1.14, AW 1.05.

Similar to worker in most respects; pronotum, mesoscutum, axillae, and scutellum coarsely foveate, and covered with a dense stubble of stiff, erect setae; foveae of mesoscutum somewhat elongate; dorsal face of propodeum longitudinally striate.

One of the two paralectotype queens at MCSN is aberrant. Unlike typical P. belti workers and queens, this queen has greatly reduced erect setae on the gaster. The queen is typical in all other respects. A queen collected from a treefall in Corcovado National Park, Costa Rica, is similarly aberrant, with greatly reduced setae on both the gaster and the mesosoma. This queen was collected along with absolutely typical workers.


Procryptocerus belti is very similar to P. hirsutus. Procryptocerus hirsutus occurs in lowland Amazonia, the Guyanas, and Trinidad, and is either parapatric or allopatric with P. belti. Procryptocerus hirsutus is larger (HW 1.0-1.3mm [n=7] for P. hirsutus versus 0.88-0.99mm [mean=0.93, n=12] for P. belti). The mesonotum is longitudinally rugose in P. hirsutus, reticulate rugose in P. belti figure) (with the exception of a specimen from Bugaba, Panama). The outer surface of the metatibia is coarsely rugose in P. hirsutus, relatively smooth in P. belti. The first gastral tergite is always uniformly punctate in P. belti, but in P. hirsutus it is variable, ranging from densely punctate to nearly smooth.

See P. pictipes for a discussion of character variation and possible phylogenetic relationships among P. belti, P. hirsutus, P. convexus, and P. pictipes.

Natural History

Procryptocerus belti has been collected in both canopy and understory of primary rainforest, in second growth vegetation, in beach-edge vegetation, and in mangroves. Most collections are of foraging workers from low vegetation, but four nest series were collected from narrow-guage dead stems, at least one of which was detached and lodged in low vegetation. Collections have been made in the canopies of tall trees, including Brosimum, Sloanea, Ficus, and Leuhea. Specimens have been found in the feces of Cyclopes (silky anteater).

In Costa Rica, this species prefers seasonally dry habitats. It is very abundant in the lowlands of the Pacific side, south of Puntarenas, but is rare elsewhere. At La Selva Biological Station, in the wet Atlantic lowlands, it is a very rare element of the ant fauna, occurring sparsely in the tops of canopy trees.

Types and Synonymy

Procryptocerus belti Forel 1899:46. Neolectotype worker, paralectotype queens, males: Costa Rica, Nicoya (Alfaro) [MCSN]; 2 paralectotype queens, 1 paralectotype male: same data [MHNG]. Kempf 1951:31 (redescription of all castes).

Literature Cited

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505 USA.

Date of this version: 6 December 2002

Previous versions of this page: 7 September 1998.
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