Prionopelta antillana Forel, 1909

Ladino, Natalia & Feitosa, Rodrigo M., 2020, Taxonomic revision of the genus Prionopelta Mayr, 1866 (Formicidae: Amblyoponinae) for the Neotropical region, Zootaxa 4821 (2), pp. 201-249 : 221-225

Prionopelta antillana Forel, 1909

Figures 14–17 , 35B

Prionopelta punctulata subsp. antillana Forel, 1909: 239 . Lectotype worker (here designated): ST. VINCENT AND THE GRENADINES, St. Vincent Island , Forel, CASENT0102529 (the top individual of a pin with 2 workers) [ZMUC] (examined by images). Paralectotype worker: same data as lectotype, Cotype MCZ20385 (examined by images) [MCZ].

Raised to species: Brown, 1960: 177.

Prionopelta marthae Forel, 1909: 240 . Syntype workers: VENEZUELA: Zig Zag, Forel, CASENT0102526 [MHNG] (the top specimen of a pin with 3 workers); same data (1 worker examined) (1 bottom worker misidentified) [NHMB]; CASENT0902630 (1 worker examined by images) [BMNH]. Combination in Typhlomyrmex: Brown, 1953: 104 ; in Prionopelta: Brown, 1965: 77 . New synonym.

Diagnosis. Median tooth of mandible shorter than basal tooth; anterior clypeal margin slightly projecting medially; lateral portion of frons with sparse or dense punctate sculpturing, with interspaces flat and shiny, corresponding to one or almost two puncture diameters; head with sparse pubescence in dorsal-oblique view. Twelve antennomeres. Subpetiolar process usually with margins apically convergent.

Worker measurements (n=41). HL 0.45–0.54; HW 0.37–0.45; SL 0.18–0.30; WL 0.48 –0.67; PrL 0.19–0.30; PrW 0.23–0.34; PetNL 0.12–0.17; PetW 0.20–0.28; PetH 0.14–0.22; PetL 0.12–0.20; T1L 0.18–0.28; T1W 0.27– 0.43; TL 1.23–1.67; CI 80–95; SI 45–75; PetI 125–185; PetHI 80–128; PetWI 110–171.

Queen measurements (n=3). HL 0.52–0.53; HW 0.46–0.47; SL 0.26–0.30; WL 0.76–0.78; PrL 0.14–0.18; PrW 0.30–0.40; PetNL 0.15–0.20; PetW 0.20–0.30; PetH 0.18–0.21; PetL 0.18–0.20; T1L 0.28–0.30; T1W 0.41–0.46; TL 1.77–1.80; CI 88–89; SI 55–65; PetI 125–150; PetHI 94–116; PetWI 105–150.

Worker description. Body light yellow to light brown. Integument covered mainly by dense or sparse punctate sculpturing; space between the punctures of lateral portion of frons corresponding to one or almost two puncture diameters in full-face view.

Head longer than broad; length of median tooth of mandible shorter than basal tooth; basal margins of mandibles convex. Clypeus slightly projected medially. Twelve antennomeres; antennomeres 1–4 separated by deep constrictions. Eye placed at the midlength of the head.

Pronotum broader than long. Distance between propodeal spiracle and the bulla of the metapleural gland corresponding to one spiracular diameter; distance between the propodeal spiracle and the propodeal dorsum corresponding to two or three spiracular diameters.

Petiolar node as long as high. Subpetiolar process subtriangular or falciform, with its anterior and posterior margins converging apically; posterior margin concave; posteroventral angle obtuse or acute.

Queen. Similar to workers, with the expected morphology of Prionopelta queens.

Male. Our translation of the description provided by Forel (1893) is: “L. 2.5 mm. Very similar to Amblyopone males, particularly to A. gheorghieffi Forel ; but the wings have only one cubital cell and the transverse vein has an ulnar ramification. Hypopygium ends in an elongated medial tip, hairy and obtuse at its apex. External genital valves are very obtuse. The pygidium is rounded. Petiole is rounded, with a slight posterior slope, with a small, barely visible tubercle underneath. Head large, rounded; eyes very far forward; small ocelli. Shiny, finely reticulate. Pilosity erect, yellowish, very fine, short, oblique on tibiae and elsewhere (turning to pubescence), quite abundant. Pale yellowish-brown […]”.

Etymology. Although not explicit in the original description, the name certainly refers to the type locality, “Antille St. Vincent ”.

Distribution ( Fig. 35B ). Prionopelta antillana is known from Marion County and Sumter County in Florida, and the Caribbean Islands to south Brazil.

Comments. Forel (1909) presented the first key for the identification of the Neotropical species of Prionopelta . In this key, P. marthae and P. punctulata subsp. antillana appear in the same couplet, with some ambiguous characteristics separating both species.

Almost 50 years after its description, P. marthae was considered a junior synonym of Typhlomyrmex rogenhoferi Mayr, 1862 ( Brown 1953) , based on a Typhlomyrmex specimen mislabeled as syntype of P. marthae located in the collection of William M. Wheeler (MCZ). In consequence, the species was excluded from the key provided by Brown (1960). Later, the species was recognized as a member of Prionopelta , close related to P. antillana , and was transferred to this genus by Brown (1965).

The examination of type specimens revealed that the bottom specimen mounted on the pin that holds syntypes of P. marthae deposited at NHMB belongs to the myrmicine genus Solenopsis . Also, the “cotype” specimen deposited in MCZ under the code MCZ-ENT00020384 belongs to the ectatommine genus Typhlomyrmex .

Initially, subtle differences seemed to separate P. antillana and P. marthae , according to the original descriptions and among specimens accumulated in scientific collections, specifically regarding the head dorsum sculpturing, the shape of the subpetiolar process and the width of the first gastral segment. In fact, type specimens of P. marthae and P. antillana show morphological differences (CASENT0102526, CASENT0902630, CASENT0102529 and MCZENT20385). However, both forms are highly overlapped in their wide distribution, and the morphology follows a continuous variation that blurs the limits between the species. This was supported by the analysis of the measurements that showed a very close relationship between the individuals, in terms of variation and discrimination of groups (Fig. 36A, B). Still, we saw that some specimens of São Paulo, Paraná and Santa Catarina, Brazil, show a denser sculpturing on the head dorsum and different degrees of convergence between the margins of the subpetiolar process, features not considered in the statistical analysis. Considering the statements above, we synonymized P. marthae with P. antillana . Also, we believe that P. antillana still may harbor a complex of cryptic species difficult to resolve with morphology alone.

Dr. James Wetterer (pers. comm.) made a great effort to illuminate the geographic spread of P. antillana . The following account is based on Dr. Wetterer’s notes on published and unpublished records of the species: “ P. antillana is a tiny ant with records from the West Indies, South America, Central America and subtropical central Florida […] I have collected the species at 48 sites on the West Indian Islands of Grenada (2), Guadeloupe (2), Martinique (5), Montserrat (4), Nevis (8), St. Kitts (8), St. Lucia (3), St. Vincent (8), and Trinidad (8). The islands of Grenada, Montserrat, Nevis, St. Kitts and St. Lucia have not reported the presence of the species so far […]. There is a difficulty in the distinction of P. antillana and P. amabilis , and then a probability of misidentification between both species in the records […]. Although Brown (1960) considered that the species was introduced to the Lesser Antilles, recent collecting have much filled the distributional gap. The current distribution of P. antillana is now understood considering the natural spread through short-distance island-hopping.”

Part of the specimen records cited by Dr. Wetterer were confirmed in our work, and some of the unconfirmed ones follow the distribution of the species presented here ( Fig. 35B ). Nevertheless, our work only considers material examined directly by us or through high resolution images.

Forel (1893) provided the description of a male specimen said to be P. punctulata collected at St. Vincent by Mons. H.H. Smith, as well as field annotations from the latter author. As insightfully noted by Dr. Flavia Esteves (pers. comm.) and in line with the distributions recognized here for P. punctulata and P. antillana , the male described by Forel actually belongs to P. antillana .

Natural history. The species is mainly known from pitfall traps and leaf litter samples collected in tropical forests. It is reported at elevations of 200-1010m.

Field annotations provided by Mons. H.H. Smith of specimens from St. Vincent under the name of P. punctulata are presented in Forel (1893). We summarize this information as follows: somewhat common and sluggish ants, generally found in shady and damp places, sharing the substrate with other ants. Differences between workers and queens do not seem to be very obvious.

Deyrup et al. (2000) reported that the species may be introduced from the Lesser Antilles or Central America to the state of Florida, USA, where it is “common in rotten wood in parts of Marion and Sumter County”.

The following account is based on the detailed observations of Deyrup et al. (2016) about the presence of P. antillana in Florida: the worker caste of the species is small and cryptic, collected in soil, under low evergreen scrub oaks, in mesic hammocks, sand pine scrub and leaf litter samples; known from a 2004 expedition near the Big Scrub Campground in Ocala National Forest and during the Florida ant survey. This species is the unique record of the genus in the United States, probably imported to Marion County from West Indies, it spread slowly ever since, and eventually should occupy southern Florida. The city of Silver Spring and a botanical garden located there might be the entering site for the introduction of the species, since famous films supposedly set in the tropics were filmed there, like 1930s Tarzan movies with Johnny Wissmuller, in which aquatic adventures in Silver Springs are jarringly intermixed with odd footage from Africa and elsewhere. Perhaps tropical plants were brought for some scenes. These last statements about the origin of the species introduction in Florida were also noticed by Dr. Andrea Lucky (pers. comm.) and discussed.

Additional material examined (259 specimens). BOLIVIA: Santa Cruz: Buena Vista, -17.45 -63.66667, 350m, 18.xii.1993, P.S. Ward col., PSW12438, second-growth rainforest, sifted litter, CASENT0006076 (1 worker) [UCDC]. BRAZIL: Distrito Federal: Brasilia, Tabatinga, F.Z. Cooperbrás, 2003-2004, Schmidt F.G.V. col., pitfall (1 worker) [CEPEC]. Espirito Santo: Sta. Teresa, 25.i.1994, I.C. Nascimento col., #4782 (7 workers) [DZUP]. Goiás: Jataí, Faz. Primavera, 17°51’54’’S 51°39’56’’W, 817m, 09.xi.2008, G.G. Santos col., Mini-Winkler (17 workers, 1 queen) [DZUP]. Faz. Santa Lúcia 17°50’15.7’’S 52°2’23.9’’W, 793m, 11.x.2008, G.G. Santos col., Mini-Winkler (1 worker) [DZUP]. Mta. Açude, 17°51’31’’S 51°43’37’’W, 21.xii.2005, G.G. Santos col., Mini-Winkler (1 worker, 1 queen) [DZUP]. Maranhão: Açailândia, Horto Fazenda Pompéia, 04°52’30’’S 47°17’40’’W, 13-22.ii.2006, Silva R.R. & Feitosa R.M. cols., Winkler (4 workers) [MZSP]. Balsas, Mata do Capão do Catulé, 09°22’53.8’’S 46°44’59.3’’W, 22.ix-05.x.2006, Silva R.R. & Feitosa R.M. cols. (1 worker) [MZSP]. Minas Gerais: Parna do Cipó, Cachoeira da Farofa, -19.379412 -43.575782, 877m, 11.v.2016, J. Chaúl col., #014, Winkler, epigaeic, ANTWEB1032567 (1 queen) [UFV]. Paraná: Morretes, Parque Estadual do Pau-Ôco, 25°34’33.5’’S 48°53’19.5’’W, 6-11.v.2002, Silva R.R. & Dietz B.H. cols., Winkler (9 workers) [MZSP]; (2 workers) [DZUP]. Rondônia: Porto Velho, Área Abunã, A11P1, 09°38’36’’S 65°26’54’’W, 02-16.x.2013, Mazão G.R. & Mendoça R.T.T. cols. (1 worker) [DZUP]. Santa Catarina: Blumenau, 27°06’15’’S 49°09’14’’W, 20-27.x.2000, Silva R.R. col., Winkler, solo (5 workers) [MZSP]; same data, P.E. Nascentes, 27°01-06’S 49°01-10’W, 10.ii.2001, Eberhardt col., Winkler (1 worker) [MZSP]. Morro da Serra, xii.1958, F. Plaumann col. (1 worker) [MZSP]. Palhoça, PE Serra do Tabuleiro, 27°44’28’’S 48°41’50’’W, 02-10.vi.2003, Silva R.R., Dietz B.H. & Tavares A. cols., Winkler (25 workers, 3 queens) [MZSP]; same data (2 workers) [DZUP]. São Bento do Sul, APA Rio Vermelho, 26°21’51’’S 49°16’16’’W, 30.iii-04.iv.2001, Silva R.R. & Eberhardt F. cols., Winkler (19 workers) [MZSP]; (4 workers) [DZUP]. São Paulo: Faz. Intermontes, iv.2009 (1 worker) [MZSP]. M. Cruzes, R. Itatinga, 23°45’02’’S 46°07’63’’W, 720m, 12.vii.2000, M.S.C. Morini col., Winkler, área de mata (1 worker) [CEPEC]. Tapiraí, 24°01’55’’S 47°27’56’’W, 08-14.i.2001, Silva & Eberhardt cols., Winkler (2 workers) [MZSP]. Ubatuba, P.E.S.M. N. Picinguaba, 23°17’54.4’’S 44°47’49.2’’W, 600m, 23.i.2006, Scott-Santos C.P. & Santos E.F. cols., Winkler (3 workers) [MZSP]; same data, 23°18’21.6’’S 44°48’25.2’’W, 400m, 05.i.2006 (5 workers) [MZSP]; same data, 19.iii.2006 (2 workers) [MZSP]; same data, 23°19’08.4’’S 44°49’4.8’’W, 200m, 18.iii.2006 (3 workers) [MZSP]. Tocantins: Recursolândia, Mata Ciliar Rio Mateiros, 08°45’28.6’’S 47°02’20.7’’W, 09-12.v.2005, Silva R.R. & Dietz B.H. cols., Winkler (15 workers) [MZSP]. COLOMBIA: Antioquia: La Calandria, 06°46’31’’N 75°05’53’’W, 1010m, 08.v.1998, F. Serna col. (2 workers) [DZUP]. Magdalena: 4km N. San Pedro 10°57’N 74°03’W, 550m, 14.viii.1985, J. Longino col., #763-S, wet forest, litter sample, LACM ENT 142650 (2 workers) [JTLC]; same data, 10.95 -74.05, P.S. Ward col., PSW07912-2, rainforest, sifted litter (leaf mold, rotten wood), CASENT0260463 (2 workers) [PSWC]. ECUADOR: Zamora-Chinchipe: ENE Yantzaza, Estación El Padmi, 18.7 Universidad Nacional de Loja, 3°44’44.59’’S 78°36’51.70’’W, 835m, 14.vi.2014, C. Gómez, M. Tuza, G. Piedra, M. Vélez & J. Lattke col. (2 workers) [MZSP]; (21 workers) [DZUP]. FRENCH GUIANA: Saül: Mont Chauve, 250m, 24.iv.1997, R. Garrouste col., (6 workers) [CEPEC]; (1 worker) [DZUP]. GUADELOUPE: Basse Terre: Piton de Ste. Rose, 16.33166 -61.76206 ± 50m, 320m, 26.v.2012, R.S. Anderson col., #RSA2012-148, ex. sifted leaf litter, deciduous forest, CASENT0630440 (1 worker) [JTLC]. PERU: Cusco: Est. Biol. Villa Carmen, -12.902437° -71.407672° ± 300m, 590m, 05-15.viii.2013, Ant Course 2013 cols., bamboo forest, secondary vegetation (1 worker) [DZUP]. Madre de Dios: Est. Biol. Villa Carmen, -12.875296° -71.410954°± 300m, 650m, 05-15.viii.2013, Ant Course 2013 cols., rainforest, (2 workers) [DZUP]; same data, -12.902437° -71.407672° ± 300m, 590m, bamboo forest, secondary vegetation (1 worker) [DZUP]. Tambopata Research Center, -13.14535 -69.61483 ± 100m, 276m, 01.vii.2000, D. Feener col., TRC-S14-007-R1C10, ex. sifted leaf litter, bamboo forest, CASENT0635236 (1 worker) [JTLC]. SAINT VINCENT AND THE GRENADINES: St. Vincent, Vermont Nature trail, 13.21632 -61.21416 ± 25m, 365m, 05.v.2015, B.L. Fisher col., BLF#37240, rainforest, ANTWEB, CASENT0767588 (1 worker) [CASC]; BLF#37241, CASENT0768612 (1 worker) [CASC]; CASENT0768611 (1 worker) [CASC]; BLF#37243, CASENT0767564 (1 worker) [CASC]; CASENT0767562 (1 worker) [CASC]; BLF#37248, CASENT0767570 (1 worker) [CASC]; BLF#37248, CASENT0767569 (1 worker) [CASC]; BLF#37233, CASENT0767621 (1 worker) [CASC]; same data, 18.v.2015,B.L. Fisher col., BLF#37246, hand collection, sifted litter, miscellaneous collection, not a nest series, CASENT0767612 (1 worker) [CASC]; same data, 12.v.2015, BLF#37240, CASENT0767588 (1 worker) [CASC]. SURINAME: Poeroe mankemisa: ix.1959, I.v.d. Drift col., 2-xxla-5 (1 worker) [MZSP]. Tambah-redjo: vi.1959, I.V.D. Drift col., 42-viiicd-2 (9 workers) [MZSP]; (3 workers) [DZUP]; same data, 45-DVla-7 (3 workers) [DZUP]; same data, 1-viiib-6 (2 workers) [MZSP]; same data, 38.VLcd-12 (3 workers) [MZSP]. UNITED STATES: Florida: Marion, Ocala Nat. Forest, Big scrub camp area, 29.08017 -82.25817, 28.viii.2004, Deyrup M. col., ANTC5127, Quercus geminata thicket, introduced, CASENT0103911 (5 workers) [ABS]. VEN-EZUELA: Apure: Caño Maporal ca. Est. Unellez, 21.viii.1983, J. Lattke col., #455, CASENT0810393 (3 workers) [MIZA]. Aragua: Henri Pittier National park, 10.36667 -67.82667, 860m, 03.ix.2003, E. Rodríguez, A. Grotto & J. Lattke cols., JEL2842, La Esperanza, Bosque Semi decíduo, ex. hojarasca, CASENT0178694 (1 worker) [MIZA]. Parque Nacional Henri Pittier, 10°22’8”N 67°49’29”W, 870m, 03.iii.2003, E. Rodríguez, R. Luján & J. Lattke cols., Winkler, La Esperanza (nome de um setor na montanha), floresta semi-decídua (21 workers) [DZUP]; (1 worker) [MZSP]; (2 workers) [NHMB]; same data, Finca Sta Maria, 10.3602° -67.8219°, 650m, 15.viii.2003, J. Lattke col., #2669, soil sample (1 worker, 1 queen) [DZUP]. Portuguesa: Qda. La Guata, 12km de Biscucuy, 600m, 21.v.1983, #464, CASENT0810394 (3 workers) [MIZA]. Táchira: Vía Sta. Ana, Río Frío, 1000m, 14.viii.1983, J. Lattke & G. Borges col., CASENT0810424 (4 workers) [MIZA].

Figures

FIGURE 14. Lectotype worker of Prionopelta antillana (Saint Vincent and the Grenadines). A. Full-face view; B. Lateral view; C. Dorsal view. Modified from AntWeb.org images by April Nobile, specimen: CASENT0102529.

FIGURE 15. Worker of Prionopelta antillana (Saint Vincent and the Grenadines).A. Full-face view; B. Lateral view; C. Dorsal view. Modified from AntWeb.org images by Michele Esposito, specimen: CASENT0767588.

FIGURE 16. Queen of Prionopelta antillana (Brazil, Goiás). A. Full-face view; B. Lateral view; C. Dorsal view.

FIGURE 17. Worker of Prionopelta antillana (Ecuador, Zamora-Chinchipe). A. Head dorsum, note the sculpturing and pilosity; B. Habitus; C. Detail of subpetiolar process.

FIGURE 35. Distribution maps for Neotropical Prionopelta species. Black triangles indicate already known species, white circles indicate new species described here. Red symbols indicate the type locality of each species.