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).

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, Guatemala, Honduras, Lesser Antilles, Mexico, Panama, Puerto Rico, Saint Lucia, Trinidad and Tobago.



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].