Strumigenys margaritae

In Trinidad Mark Deyrup and Lloyd Davis observed workers of S. margaritae mingled in a foraging column of Wasmannia auropunctata moving along a piece of plastic irrigation pipe on an open hillside each morning for three consecutive days. Returning to the site two years later, Lloyd Davis (personal communication) found this mixed foraging column still occurring. (Deyrup and Cover 1998)

Identification
Bolton (2000) - A member of the Strumigenys schulzi-group. The entirely densely sculptured first gastral tergite seen in margaritae is shared only with the Peruvian Strumigenys pholidota. However, in margaritae the first sternite is also weakly sculptured, standing hairs are present on the first gastral tergite, the head lacks dense longitudinal rows of appressed scale-like hairs, the mandibles and scapes are longer (compare measurements), and the dentition is quite different.

Strumigenys margaritae was the only species of this group known to occur north of Mexico. Strumigenys subnuda was described in 2010 from queens collected in Mississippi and Louisiana. In the U. S. A. margaritae has been recorded from Alabama, Florida, Georgia and Texas (M. R. Smith, 1931; Brown, 1953a; Brown, 1964; D. R. Smith, 1979; G. C. Wheeler & J. Wheeler, 1985; Deyrup, Johnson, et al., 1989).

Longino (Ants of Costa Rica) - Mandibles in side view straight, not broadly curved ventrally; mandibles relatively short, subtriangular, much of the apical portion meeting along a serially toothed masticatory margin when closed (former Smithistruma); leading edge of scape with a row of conspicuous projecting curved hairs, of which those distal to the subbasal bend distinctly curve toward the base of the scape; pronotal humeral hair absent; dorsal surfaces of middle and hind tibiae with decumbent to appressed short spatulate hairs; color red-brown; face punctate; sides of posterior half of mesosoma completely and densely punctulate; ventral petiolar spongiform appendages entirely obsolete; disc of postpetiole sculptured; gaster with more than 10 erect, somewhat spoon-shaped setae; propodeal teeth slender and acutely tapered, their infradental lamellae obsolete and represented only by fine carinae; basal tergite of gaster finely striolate-punctulate over entire surface, with no or very short coarse striae at postpetiolar insertion.

Distribution
This species has been introduced into Florida. It is a rare species known from a few sites in north Florida: Marion, Leon, Okaloosa and Escambia counties. Pest status: none. First published Florida record: Deyrup et al. 1989; earlier specimen: 1983. (Deyrup, Davis & Cover, 2000.)

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Anguilla, Antigua and Barbuda, Bahamas, Barbados, Belize, British Virgin Islands, Colombia, Costa Rica, El Salvador, Greater Antilles, Grenada, Guadeloupe, Guatemala, Honduras, Lesser Antilles, Mexico, Netherlands Antilles, Panama, Puerto Rico, Saint Lucia, Trinidad and Tobago.

Biology
Longino (Ants of Costa Rica) - I rarely encounter this species because I tend to concentrate my collecting in forested habitats. I have never obtained it by sifting litter. In a study of ant visitors to extrafloral nectaries of Passiflora pittieri at Sirena, Corcovado National Park, I observed many species of ants on thousands of shoots on hundreds of plants. Among these observations, I observed margaritae only twice, both times on shoots of one plant. In another study, collecting ants in scrubby roadside vegetation along the road to Monteverde (120m, La Pita), I found specimens of margaritae in sweep net samples. Finally, I found a worker while collecting in a city park in the middle of San Jose, the capital city of Costa Rica.

Brown (1953) - According to H. H. Smith (in Forel, loc. cit. 1893), margaritae is a rather common ant on St. Vincent, usually nesting in the sod layers covering rocks. The colonies at this locality were estimated to contain up to 250 individuals. One of the nests "as taken in an open place at the foot of a tree. In Alabama, Mr. Wilson took the two solitary dealate females in October and November, and also captured a stray worker from leaf litter. Dr. Goodnight found this species in soil samples in Chiapas. Thus it appears that margaritae docs not share the arboreal tendencies by other similar species with large, protruding eyes and other characters which would seem to fit it for life in epiphytes.

Atchison & Lucky (2022) found that this species, as expected, does not remove seeds.

Nomenclature

 *  margaritae. Strumigenys margaritae Forel, 1893g: 378 (w.q.m.) ANTILLES. Combination in S. (Cephaloxys): Emery, 1924d: 325; in S. (Trichoscapa): Smith, M.R., 1947f: 587; in Smithistruma: Smith, M.R. 1951a: 827; Brown, 1953g: 108; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 123. See also: Bolton, 2000: 221.

Worker
Bolton (2000) - TL 1.9-2.1, HL 0.52-0.58, HW 0.36-0.42, CI 69-73, ML 0.10- 0.12, MI 17-20, SL 0.26-0.30, SI 68-72, PW 0.24-0.26, AL 0.48-0.56 (10 measured).

Counting from base of mandible teeth 1, 3, 5, and 7 are narrow and acute, and relatively high; teeth 2, 4, and 6 are blunt apically and each is only half the height of the preceding tooth. First gastral tergite conspicuously densely sculptured everywhere, densely striolate-punctulate to shagreenate with superimposed dense striolae. Basigastral costulae very short and inconspicuous, restricted to extreme base of tergite and frequently masked by the prevalent tergal sculpture. First gastral stemite also sculptured but less strongly so, usually finely shagreenate to punctulate at least basally and laterally. Remainder of body finely densely reticulate-punctate on every surface. Apicoscrobal hair and pronotal humeral hair absent. Cephalic dorsum behind highest point of vertex without a transverse row of standing hairs. Cephalic ground-pilosity of curved narrowly spatulate hairs; between level of frontal lobes and highest point of vertex these hairs mostly directed medially. Standing hairs entirely absent from dorsal alitrunk but ground-pilosity of curved spatulate hairs distinct. Posteriorly curved or inclined short standing hairs, that are thickened apically to weakly remiform, are present on first gastral tergite. Eyes large, with 5-6 ommatidia in the longest row. Propodeum armed with a pair of narrowly triangular spines, each subtended by a very narrow lamella that may be reduced to a mere carina. Base of first gastral sternite in profile sometimes with a curved transverse carinula but without a pad of spongiform tissue.

Type Material
Bolton (2000) - Syntype workers, queens and males, ANTILLES IS: St Vincent I., Palmyra Estate, 1000 ft, 3.xi.; Golden Grove Estate, 500 ft, ix.; Hermitage Estate, Cumberland Valley, 1000 ft, 2.xii. (all coll. H. H. Smith) [examined].

References based on Global Ant Biodiversity Informatics

 * Ahuatzin D. A., E. J. Corro, A. Aguirre Jaimes, J. E. Valenzuela Gonzalez, R. Machado Feitosa, M. Cezar Ribeiro, J. Carlos Lopez Acosta, R. Coates, W. Dattilo. 2019. Forest cover drives leaf litter ant diversity in primary rainforest remnants within human-modified tropical landscapes. Biodiversity and Conservation 28(5): 1091-1107.
 * Boer P. 2019. Ants of Saba, species list. Accessed on January 22 2019 at http://www.nlmieren.nl/websitepages/SPECIES%20LIST%20SABA.html
 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * Branstetter M. G. and L. Sáenz. 2012. Las hormigas (Hymenoptera: Formicidae) de Guatemala. Pp. 221-268 in: Cano E. B. and J. C. Schuster. (eds.) 2012. Biodiversidad de Guatemala. Volumen 2. Guatemala: Universidad del Valle de Guatemala, iv + 328 pp
 * Brown W. L., Jr. 1953. Revisionary studies in the ant tribe Dacetini. Am. Midl. Nat. 50: 1-137.
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Deyrup M. 1997. Dacetine ants of the Bahamas (Hymenoptera: Formicidae). Bahamas Journal of Science 5(1): 2-6.
 * Deyrup M., L. Davis, and S. Buckner. 1998. Composition of the ant fauna of three Bahamian islands. Proceedings of the seventh symposium on the natural history of the Bahamas. 23-32. Bahamian Field Station, San Salvador, Bahamas
 * Fernandes, P.R. XXXX. Los hormigas del suelo en Mexico: Diversidad, distribucion e importancia (Hymenoptera: Formicidae).
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Fontanla Rizo J.L. 1997. Lista preliminar de las hormigas de Cuba. Cocuyo 6: 18-21.
 * Fontenla J. L., and J. Alfonso-Simonetti. 2018. Classification of Cuban ants (Hymenoptera: Formicidae) into functional groups. Poeyana Revista Cubana de Zoologia 506: 21-30.
 * Fontenla Rizo J. L. 1997. Lista preliminar de las hormigas de Cuba (Hymenoptera: Formicidae). Cocuyo 6: 18-21.
 * Forel A. 1912. Formicides néotropiques. Part II. 3me sous-famille Myrmicinae Lep. (Attini, Dacetii, Cryptocerini). Mémoires de la Société Entomologique de Belgique. 19: 179-209.
 * Galkowski C. 2016. New data on the ants from the Guadeloupe (Hymenoptera, Formicidae). Bull. Soc. Linn. Bordeaux 151, 44(1): 25-36.
 * Goodnight, C. J., and M. L. Goodnight. 1956. Some observations in a tropical rain forest in Chiapas, Mexico. Ecology 37: 139-150.
 * Kempf W. W. 1961. A survey of the ants of the soil fauna in Surinam (Hymenoptera: Formicidae). Studia Entomologica 4: 481-524.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Longino J. T. 2013. Ants of Honduras. Consulted on 18 Jan 2013. https://sites.google.com/site/longinollama/reports/ants-of-honduras
 * Longino J. T. 2013. Ants of Nicargua. Consulted on 18 Jan 2013. https://sites.google.com/site/longinollama/reports/ants-of-nicaragua
 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * MacGown J. A., and J. K. Wetterer. 2013. Distribution and biological notes of Strumigenys margaritae (Hymenoptera: Formicidae: Dacetini). Terrestrial Arthropod Reviews 6: 247255.
 * Mann W. M. 1920. Additions to the ant fauna of the West Indies and Central America. Bulletin of the American Museum of Natural History 42: 403-439.
 * Mirmecofauna de la reserva ecologica de San Felipe Bacalar
 * Morrison L. W. 1998. A review of Bahamian ant (Hymenoptera: Formicidae) biogeography. Journal of Biogeography 25: 561-571.
 * Smith M. R. 1931. A revision of the genus Strumigenys of America, north of Mexico, based on a study of the workers (Hymn.: Formicidae). Annals of the Entomological Society of America 24: 686-710.
 * Sosa-Calvo J., S. O. Shattuck, and T. R. Schultz. 2006. Dacetine ants of Panama: new records and description of a new species. Proceedings of the Entomological Society of Washington 108: 814-821.
 * Torres, Juan A. and Roy R. Snelling. 1997. Biogeography of Puerto Rican ants: a non-equilibrium case?. Biodiversity and Conservation 6:1103-1121.
 * Vasquez-Bolanos M. 2011. Checklist of the ants (Hymenoptera: Formicidae) from Mexico. Dugesiana 18(1): 95-133.
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133
 * Wheeler W. M. 1905. The ants of the Bahamas, with a list of the known West Indian species. Bulletin of the American Museum of Natural History 21: 79-135.