Procryptocerus batesi Forel 1899

Formicidae, Hymenoptera, Insecta, Arthropoda, Animalia

worker lateral view

worker face view

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

Image catalog of workers from Costa Rica, older images (click here).

Image catalog of (1) batesi queen from former syntype series, and (2) line drawing of holotype worker from Kempf 1951 (click here).

Image catalog of laeviventris holotype worker (click here).

Range

Costa Rica, Panama, Colombia.

Description of Worker

Worker measurements (n=1, Costa Rica): HW 1.281 (range 1.111-1.502, mean 1.28, n=5), HL 1.266, SL 0.846, EL 0.329, MeL 1.709, MeW 0.986, PrW 0.651, PrL 0.424, PrS 0.33, PrT 0.758, MTL 0.966, MFL 1.074, MFW 0.365, PtL 0.462, PtW 0.420, PpW 0.529, PtH 0.364, AL 1.641, AW 1.360.

Head subtriangular in outline, margin of vertex roughly straight; frontal carina extends onto clypeus, separated from and passing above torulus as a continuous flange; clypeus produced anteriorly and torulus recessed, with distinct trough anterior to torulus; face to margin of vertex with widely-spaced sharp rugae, which form areolae over entire surface, or at least peripherally and with various degrees of longitudinal orientation medially; clypeus at level of antennal insertions abruptly bent ventrad; clypeus with prominent median longitudinal carina, flanked with 3-4 longitudinal carinae on each side; lateral carinae of variable strength; genae varying from longitudinally rugose to coarsely foveate/areolate; genal bridge longitudinally striate; mandible with coarse longitudinal stria; eyes nearly symmetrically convex; 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 obtuse, weak, obsolete medially; vertex shiny with coarse, longitudinal striae radiating from occiput (of highly variable strength).

Mesonotal lobes short, acute, upturned; propodeal suture broadly, shallowly impressed, not breaking sculpture; anterolateral propodeal lobes obsolete, or with indistinct, small obtuse teeth a short distance posterior to anterolateral margin; pronotum reticulate rugose, coarsely areolate anteriorly; in some specimens rugae somewhat longitudinally parallel on mesonotum; dorsal face of propodeum reticulate rugose to longitudinally striate, with 8-10 striae; posterior face of propodeum meeting dorsal face at obtuse angle; posterior face of propodeum completely smooth and shining on ventral one half or more; one or two transverse striae dorsally, between bases of propodeal spines, or longitudinal striae extend a short distance onto posterior face; dorsal half of side of pronotum coarsely areolate-foveate; ventral half with 4-5 coarse longitudinal striae, or reticulate rugose; anepisternum areolate-foveate or with 2-3 coarse longitudinal striae; katepisternum with ² 8 longitudinal striae, these smaller than or the same size as striae on lateral pronotum, or katepisternum reticulate rugose; when katepisternum striate, striae extend onto lateral propodeum; these propodeal striae degrade into reticulate rugosity posteriorly; posterior surface of forefemur entirely smooth and shining; outer surface of metatibia coarsely rugose.

Ventral margin of petiole flat, with anterior ventrally projecting right-angled tooth; anterodorsal face of petiole shiny with coarse to faint transverse striae (completely smooth in a few specimens); posterodorsal face areolate-foveate (weakly longitudinally rugose in some specimens); postpetiole with a long, gently sloping anterior face, a broad, rounded summit near the posterior margin, and a steeply sloping posterior face; ventral margin of postpetiole short, with a prominent, acute anterior tooth; dorsum of postpetiole coarsely foveate-rugose (weakly longitudinally rugose in some specimens); first gastral tergite completely smooth or with varying expression of irregular longitudinal striae (in Costa Rica, specimens from the Cordilleras de Guanacaste and Tilar‡n and the Atlantic slope of the Cordillera Central usually lack striae on the first gastral tergite; some collections from the Cordillera Central and a collection from the Cordillera de Talamanca have striae on the anterior portion; a specimen from the Osa Peninsula has striae on both anterior and posterior portions, with the disc smooth; a specimen from Estaci—n Carrillo, on the north slope of the Cordillera Central, has the entire surface striatopunctate); microsculpture composed of hexagonal plates, these ranging from distinctly visible to completely effaced; hexagonal plates flat; first gastral sternite largely microreticulate, nearly smooth; second gastral tergite with faint, dense, granular sculpture.

Abundant flexuous setae on face, mesosomal dorsum (more than 20 on central area of promesonotum, not including those on lateral margins), petiole and postpetiole, and gaster; color shining black, with appendages gradually fading to dark brown distally.

Description of Queen

The description is based on a dealate queen from Monteverde, Costa Rica.

Queen measurements (n=1, Costa Rica): HW 1.45, HL 1.37, SL 0.89, EL 0.35, MeL 2.13, MeW 1.26, MTL 1.09, PtL 0.56, PtW 0.46, PpW 0.64, PtH 0.42, AL 1.85, AW 1.62.

Head subtriangular in dorsal view, margin of vertex somewhat erose, well-defined laterally, obscure medially, such that the margin appears cordate. In lateral view, scrobe extends straight back almost to vertex margin, then abruptly bends ventrally. Vertex shiny, with approximately 20 carinae radiating from occipital foramen. Interior of scrobe shiny. Frons coarsely areolate, as in worker. Clypeus sharply bent in the middle such that the anterior half is perpendicular to the frons. Clypeus with approximately 8 sharp longitudinal carinae which diverge anterior to the bend, leaving a deep anteromedian depression with transverse rugae and a dense tuft of golden setae. Genae similar to frons, genal bridge longitudinally striate. Mandibles with basal and masticatory margins meeting at a sharp right angle, apex of masticatory margin with three teeth of progressively smaller size, followed by two small denticles, lower half of masticatory margin completely edentate, flat. Outer surface of mandibles longitudinally striate. Scape with enlarged basal tooth extending down over neck and condyle, lower shaft subterete, becoming broader and flattened distally. Scape minutely alveolate, with outer margin faintly rugose.

Pronotum, axillae, scutellum, and dorsal face of propodeum coarsely areolate as on frons, mesoscutum tending more to discrete foveae. Posterior face of propodeum smooth and shiny except for 1-2 transverse carinae between spine bases. Sides of pronotum grading into coarse longitudinal striae. Similar striae covering dorsal half of katepisternum, extending about half way across the propodeum; rest of sides of mesosoma, including anepisternum, coarsely areolate. Forecoxae transversely striate, meso- and metacoxae unsculptured. Propodeal spines triangular, just under half the length of the dorsal face of the propodeum. Femora strongly swollen medially, spindle-shaped. Exterior surfaces of tibiae longitudinally rugose-areolate, rest of legs smooth and shining.

Petiole elongate with gently convex dorsal surface, ventral surface concave, with small anterior tooth. Postpetiole with short, stout anteroventral tooth. Anterior face of petiole shiny with a few transverse striae. Posterior face of petiole and dorsum of postpetiole coarsely areolate; gaster completely unsculptured except for sparse, minute piligerous puncta, and very narrow traces of rugae at the margins of terga and sterna.

Body and appendages completely covered with short, filiform setae; first gastral tergite also with sparse, very short subdecumbent setae; color uniformly black.

Comments

In the mountains of southern Central America and South America, a complex of species occurs that have (1) the frontal carinae separate from the torulus, passing above it and onto the clypeus; (2) the face sculpture varying from completely striate to strongly clathrate (composed of high, sharp, well-separated rugae, which form irregular polygons over face surface); and (3) first gastral tergite varying from striate to completely smooth and shining. The complex occurs as a series of allopatric populations restricted to montane forests. There is abundant material from Costa Rica, which reveals the presence of two sympatric species. The populations in Costa Rica and western Panama are peripheral isolates, with the nearest neighbors being populations in the Colombian Andes. Collections occur from Venezuela, through Colombia and Ecuador south to Peru, but they are too few to draw conclusions about communities of sympatric species or the nature of character variation. Character variation is high even within Costa Rica, and discordant character variation occurs across the material from South America. Each local mountain range may host a unique community, shaped by a combination of dispersal history, local selection, and perhaps hybridization. As a result, a clear taxonomy of these forms may be elusive.

A discrete character that separates sympatric forms in Costa Rica is the presence or absence of a torulus trough. The torulus trough is an effect of the shape of the lateral portion of the clypeus. In specimens lacking a trough, the lateral portion of the clypeus falls perpendicularly to the torulus, such that in anterior view (looking at the head with mandibles forward) the torulus is relatively exposed. In specimens with a trough, the lateral clypeus is somewhat produced, such that it falls to the torulus at an acute angle, and in anterior view the torulus is relatively obscured by the lateral "wings" of the clypeus. South American material exhibits a full range of states for this character, from no torulus trough to a deep, pronounced one.

Current available names in this complex are P. carbonarius Mayr, 1870 from Colombia, P. rudis Mayr, 1870 from Colombia, P. batesi Forel, 1899 from Colombia, P. laeviventris Forel, 1899 from Panama, P. mayri Forel, 1899 from Colombia, P. reichenspergeri Santschi, 1921 from Brazil, and P. virgatus Kempf, 1964 from Ecuador. Kempf synonymized P. laeviventris under P. carbonarius. Longino and Snelling (2002) moved laeviventris to synonymy under batesi and synonymized reichenspergeri under mayri. The type of P. laeviventris, from western Panama, clearly falls within the Central American group with the torulus trough. In Colombia, species boundaries are unclear. The types of P. rudis, P. batesi, and P. carbonarius all have a torulus trough, but they vary in gastral sculpture and body size. The type of P. laeviventris most closely matches P. batesi, not P. carbonarius. Therefore Longino and Snelling transferred it from P. carbonarius to P. batesi, and identified as P. batesi the Central American material with a torulus trough. The types of P. mayri and P. reichenspergeri match the Central American species that lacks a torulus trough. Procryptocerus virgatus, from Ecuador, has a weak torulus trough. It and other material from Ecuador and southern Colombia exhibit variation in the torulus trough that blurs the distinct character states found in Central America.

Also see discussion under rudis group.

Natural History

Most collections are of foraging workers obtained from montane wet forest, on low vegetation or in the canopy. No collections are known from below 600m elevation. Workers are often observed in recent treefalls. Procryptocerus batesi appears to be very similar to P. mayri in its habitat preference and nesting habits (see additional notes under P. mayri). Nests contain fewer than 100 workers, and may be found in live or dead stems. Colonies appear to be monogynous. Polydomy probably occurs because queenless nests can be found. The following data on nest collections are extracted from field notes, all from Costa Rica:

Longino, 23-24 Jul 1984, Rio Pe–as Blancas: an entire nest was collected in a hollow, living stem of an epiphytic shrub, 20m high in a Guarea tree. The nest contained 55 adult workers, 1 dealate queen, 1 adult male, 3 pupae, 13 large larvae, and a small amount of smaller brood.

Longino #1601, Casa Eladio, Rio Pe–as Blancas: an entire nest was collected from one internode of a Cecropia insignis sapling. The nest contained 87 adult workers, 58 pupae, 10 prepupae, 18 large larvae, and a few small larvae and eggs.

Longino #2356, Cerro Cacao: an entire nest was collected from a dead branch. The nest contained 96 workers, 1 dealate queen, and brood.

Types and Synonymy

Procryptocerus batesi Forel 1899:43. Lectotype worker: Colombia (Landolt) [MHNG]. Kempf 1951:22-24, fig. 22 (lectotype designation and redescription of worker).

Procryptocerus carbonarius var. laeviventris Forel, 1899:47. Holotype worker: Panama, Volc‡n de Chiriqu’ (Champion) [MHNG]. Synonymy by Longino and Snelling 2002.

Procryptocerus carbonarius (part): Kempf, 1951:27. Incorrect synonymy of P. laeviventris under P. carbonarius.


Literature Cited

Page author:

John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu

Date of this version: 6 December 2002.


Previous versions of this page: 4 September 1998
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