Typhlomyrmex clavicornis Emery, 1906

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 clavicornis Emery

Figs 2 , 6B

Typhlomyrmex clavicornis Emery, 1906: 112. Alate queen, Bolivia.

Typhlomyrmex clavicornis var. divergens Forel, 1906: 248. Queen and male, Paraguay, synonymy in Brown 1965: 71.

Typhlomyrmex richardsi Donisthorpe 1939: 161. Male, Guiana. Synonymy in Brown 1965: 71.

Material examined.

Colombia: Caquetá, Albania, Vda. Samaria, Fca. Buenavista, 01°18'12"N, 75°52'23"W, 266 m, 26.iii.2019, leg. E. Durán, 1 worker and 1 female alate (LEUA 00000050569); Sebastopol, 01°43'00.12"N, 75°36'49.3"W, 527 m, 29.iii.2016, leg. D. Castro, 2 workers (CATAC-02562; 02563); Palmichar, 01°42'52.2"N, 75°36'53.6"W, 241 m, 23.iii.2016, leg. Y. Virguez, 1 worker (CATAC-00292); Tarquí, 01°50'36.4"N, 75°40'18.3"W, 1247 m, 5.iv.2016, leg. Y. Virguez, 5 workers (CATAC-01025); Vda. La Viciosa, CIMAZ Macagual, 01°30'23"N, 73°30'43"W, 250m, 16.vi.2019, leg. E. Durán, 1 worker and 1 female alate (LEUA 00000043623; 00000043633); Belén de los Andaquíes, 01°42'6.8"N, 75°53'57.5"W, 1500 m, 23.i.2017, leg. D. Castro, 3 workers (CATAC-00893); Morelia, Vda. Campoalegre, Fca. Buenavista, 01°19'21"N, 75°43'12"W, 257 m, 11.vi.2022, leg D. Coy, 2 workers (LEUA 00000050566; 00000050567); San Jose del Fragua , Bellavista, 1°19'16.21"N, 76°00'21.30'W, 504 m, 4.xii.2018, leg- M. Perez, 1 worker (CATAC-04222); Putumayo, Puerto Leguizamo, La Tagua, 00°05'14.9"S, 74°36'38.4"W 182 m, 14.vii.2016, leg. D. Castro, 1 worker (CATAC-00242) .

Worker description.

Head. Quadrated, as wide as long. Vertex very slightly concave, occipital corners rounded. Sides of head slightly convex, its greatest width towards one third of the vertex. Anterior margin of the clypeus slightly convex, without any type of projection or prolongation. Eyes reduced to one ommatidia situated in anterior third of the capsule sides; antennal sockets totally concealed by the frontal lobes; frontal lobes elongate and rounded; toruli circular and separated, visible by transparency through the frontal groove integument. Antennae 12-segmented with a well-defined 3-segmented club. Scapes short, and stout, their distal end at rest distant from the vertexal margin; pedicel about twice as long as wide, and about as long as the 3 following segments together, segments A3-A9 short, much wider than long; segments 10 to 12 forming antennal club; mandibles short and subtriangular; mandibles closed do not fit completely with anterior clypeal margin, masticatory margin with a series of small teeth followed by a large long apical tooth.

Mesosoma. Subrectangular in lateral view; pronotum anteriorly rounded in dorsal view, much wider than long, strongly sloping and without a pronotal carinae; promesonotal suture well defined dorsally; mesonotum flat dorsally; metanotal groove marked distinct and marked by small carinae in profile view; anterior face of propodeum expanded, forming a rounded corner; posterior face of propodeum straight and steep; propodeal spiracle large, circular, equidistant from the dorsal and lateral margins of the propodeum, its diameter (0.062 mm) roughly equal to the length of the penultimate antennomere.

Metasoma. Petiole in lateral view higher than long, its front face flat, delimited from the lateral faces by a sharp corner. Node dorsum slightly convex and short. Petiole spiracle distant from the leading edge by a length greater than its diameter; sub-petiolar process prominent and lobe-shaped, tapering to a downward point.

Sculpture. Body generally opaque with restricted smooth shiny areas, like areas of mesopleura. Front of head with a sculpture that is a mixture of points and faint striations. Oblique longitudinal striation better marked towards the sides of the head and more visible in oblique lateral view. Short longitudinal striation limited to the lower part of the sides of the propodeal, below the propodeal spiracle and partly on the propodeal bulla.

Pilosity and color. The whole body with a dense and short pubescence. A few erect, longer hairs (length about penultimate antennomere) on dome of clypeus and back of petiole. Light brown color, whitish hairs. Outer surface of the mid tibiae with a series of hard, spiniform, erect, dark hairs, which contrast and mix with the soft, light, and ordinary hairs.

Measurements. HW 0.723, HL 0.709, SL 0.450, PrW 0.487, PeW 0.360, PeL 0.395, PeH 0.319, WL 1.01, CI 102, SI 62, TL 3.31.

Diagnosis and comments.

According to Brown (1965: 71) the queens and workers of this species are distinguished by a prominent antennal club and mandibles with a long apical tooth (see Brown 1965, Fig. 4 ). Lacau et al. (2004) also add the presence of spiniform hairs on the mesotibiae (a feature shared with T. meire ). Two workers examined in the CATAC collection were identified as T. meire (CATAC-02562; 02563), although the mesotibia have spiniform hairs and the antennae have 12 segments and not 10 (as in T. meire ) so we do consider these workers were misidentified. T. meire was reported from Colombia in a previous checklist ( Castro et al. 2018b) and recorded in Ant Maps, but here we identify these records as T. clavicornis . Brown (1965) does not mention the possession of spiniform hairs for T. clavicornis , a feature that he would surely have noticed, so the question remains as to what the limits of this species are. Until now, there are no valid records of T. meire from Colombia.

There is little variation in the material examined, especially in the teeth of the mandibles, which can be small and uniform, of various sizes, or almost invisible (worn), but the apical tooth is always prominent. In females, the spiniform hairs of the mesotibiae are more noticeable. The metafemur appears more enlarged in the anterior view, which would explain why a specimen from LEUA (00000050566) is identified as T. major . However, in T. major this widening is abrupt after a short margin (see fig. 4C in Lacau et al. 2008), which does not occur in the LEUA specimen. On the other hand, in T. major the scape is slightly longer, the propodeal spiracle is smaller, the mesotibia presumably do not have spiniform hairs, and the petiole has a more visible peduncle.

Distribution.

Species widely distributed in South America, with valid records in Colombia, Bolivia (type-locality), Paraguay, Guyana, and Brazil with only one record worth for the state of Rio de Janeiro (see discussion). In the literature it is also recorded for French Guyana and Surinam ( Fernández and Sendoya 2004), however, no coordinates or valid records were found for this information. However, it is evident that it is a species of wide distribution, with records in the Amazon, Chaco, Cerrado and the Atlantic Forest.

Biological notes.

The analyzed material was collected in soil and litter, though the species was predominantly found in deep soil strata (<20-30 cm). The soil specimens were found at 10 cm to 30 cm depth, while they were absent in the 0-10 cm stratum; more than half of the specimens were found in the 10-20 cm stratum, and the largest number of individuals from the same sample were collected in the depth of 20-30 cm (8 individuals), while in litter only one individual per sample was found. Likewise, this species was found in different coverages, both natural and intervened, although it stands out that most occurrences were in pastures. Typhlomyrmex clavicornis was also collected in secondary and primary forests.

Figures

Figure 2. Photomicrographs of Typhlomyrmex clavicornis (CATAC- 02562) 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 4. Photomicrographs comparing the mesofemur and mesotibia of A T. encanto sp. nov. B T. clavicornis C T. prolatus. Arrow pointing out the highly modified spiniform setae found only in the mesotibia of T. clavicornis. Scale bars: 0.2 mm (A, C); 0.1 mm (B).

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.