Typhlomyrmex encanto, Fernández & Fiorentino & Castro, 2023

Fernandez, Fernando, Fiorentino, Gianpiero & Castro, Daniel, 2023, A new species of Typhlomyrmex from Colombia, re-description of the worker of T. clavicornis Emery, description of the worker of T. prolatus Brown, and key of known species (Hymenoptera, Formicidae), Journal of Hymenoptera Research 96, pp. 579-597 : 579

Typhlomyrmex encanto sp. nov.

Figs 1 , 6A

Typhlomyrmex sp. A Lacau et al. 2008.

Holotype worker.

Colombia, Amazonas, El Encanto, 01°44'3.48"S, 73°11'57.7"W, 156 m, 14-17.iv.2022, leg. L. Pérez & R. Nova (ICN 103630).

Paratype.

1 worker, same data as holotype (ICN 103631).

Non-type material examined.

Colombia, Vaupés, Pacoa. Río Causuarí, Cerro Morroco, 00°08'19.2"N, 73°11'57.7"W, 195 m, 26.ii.2018, leg. D. Luna & W. Gómez, 2 workers (ICN 103632).

Worker description.

Head. Rectangular, longer than wide. Vertex slightly concave in the middle, occipital corners rounded. Sides of head slightly convex, its greatest width towards the middle of the head. Head narrowed anteriad. Anterior margin of the clypeus slightly convex, with a short and prominent truncated lobe. Eyes reduced to an ommatidium towards the position of the apical third of the head; antennal sockets fully concealed by the frontal lobes; frontal lobes short and subquadrate; toruli circular, antennae 12-segmented with a well-defined 3-segmented club; scape conspicuously curved ventrally at half of its apical length in frontal view, the maximal width nearly equal to pedicel length; when folded backward, scape does not reach the vertexal margin; pedicel about as long as wide, and about as long as the 3 following segments together; segments A3 to A9 very short; segment 10 to 12 forming antennal club; mandible shape elongated-subtriangular, the apical margin joining basal margin at a strongly rounded angle; masticatory margin with a series of small teeth followed by a larger apical tooth.

Mesosoma. Lightly curved and irregular in lateral view, pronotum anteriorly rounded in dorsal view, longer than wide and strongly sloping anteriorly in lateral view, its posterior part curved, mesonotum slightly convex, promesonotal suture well marked, propodeal sutures feebly marked. Propodeal spiracle small, circular, equidistant from the dorsal and lateral margins of the propodeum, its diameter (0.012 mm) roughly equal to the length of the 8th antennomere; dorsal face of the propodeum weakly inclined and convex, gradually rounding beyond the spiracle towards the sloping posterior face; propodeal spiracle opened laterally, its large orifice bordered by a thin cuticular ring; propodeal lobes lacking.

Metasoma. Petiole in lateral view higher than long, with short and stout peduncle; its front face flat, delimited by a poorly defined carinae; dorsum strongly rounded and short. Petiole spiracle distant from the leading edge by a length greater than its diameter. Sub-petiolar process elongate and forward facing, lobe-shaped tapering to a downward point. First tergum with prora marked.

Sculpture. Body generally opaque with restricted smooth shiny areas on the mesopleura; front of head with a sculpture that is a mixture of points and uniform longitudinal striation short, faint longitudinal striation limited to the pronotum and the lower part of the sides of the propodeum, below the propodeal spiracle and partly on the propodeal bulla.

Pilosity and color. The whole body with a dense and very short pubescence. Erect hairs absent. Light brown color. Outer surface of the mid tibiae without a series of hard, spiniform hairs.

Measurements. HW 0.339, HL 0.413, SL 0.211, PrW 0.204, PeW 0.129, PeL 0.186, PeH 0.154, WL 0.488, CI 82, SI 62, TL 1.57.

Diagnosis and comments.

A unique feature in Typhlomyrmex encanto sp. nov. is the median projection of the clypeal lamella, not known in any other described Typhlomyrmex . This species is also the smallest of the genus, and probably the smallest Ectatomminae in the World. In their treatment of the Typhlomyrmex from Colombia, Lacau et al. (2008) include one unnamed species, referred to as "sp. A" which matches the description of Typhlomyrmex encanto sp. nov. In the key to the species, the following characterization of species A can be obtained, translated from French: "Head capsule whose maximum width is located at half its length, with lateral surfaces clearly converging anteriorly; occipital carina absent; clypeus in dorsal view, with the anterior edge forming a distinct constricted convexity; clypeal lamella bearing a short and narrow median process (its maximum width clearly less than that of the scape), protruding and clearly truncated at the apex; scape in dorsal view greatly enlarged posteriorly at its basal third; indistinct metanotal groove". The authors refer to material of this species from Brazil, Colombia and Peru and mention that the description is "in progress". However, this description was not published and there are no known plans to do so (Jacques Delabie, pers. comm.). Lacau et al. (2008) also mention material from Leticia, Amazonas, Colombia, was deposited in the Museum of Comparative Zoology at Harvard University (MCZ).

Distribution.

This species is recorded for the Colombian Amazon and, as mentioned above, Lacau et al. (2008) reports this species also for Brazil and Peru without coordinates or collection vouchers, with the available information this species seems to be restricted to the Amazon region of South America.

Biological notes.

This species was collected in leaf litter with the Winkler method, in primary rain forests with a high degree of conservation.

Etymology.

This species is named in honor of the "El Encanto", locality where the type-material was collected; Also, encanto is a Spanish word that means “charm”, and refers to the Disney movie Encanto (2021) based on Colombian culture.

Figures

Figure 1. Photomicrographs of Typhlomyrmex encanto sp. nov. (ICN 103630) A head in frontal view B body in dorsal view C body in lateral view. Scale bars: 0.2 mm (A); 0.5 mm (B, C).

Figure 6. Distribution maps A Typhlomyrmex encanto sp. nov. B Typhlomyrmex clavicornis C Typhlomyrmex prolatus. Note: Literature record refers to records in the literature with coordinates available, records in literature without coordinates are not indicated in maps, but are mentioned in the distribution section of each species.