Strumigenys eggersi

An unusual Dacetine in its tolerance for inhabiting relatively dryer habitats.

Identification
Bolton (2000) - Among the species closest related to Strumigenys gundlachi, eggersi is isolated by the characters in the description (see below). It separates from Strumigenys denticulata, with which it shares the characters of extreme reduction or absence of postpetiolar appendages, by its shorter mandibles (MI 58 - 65 as opposed to MI 72 - 85 in denticulata), presence of a pair of standing hairs anteriorly on the pronotum, and more strongly sculptured gaster. Pyramica eggersi and P. gundlachi are the only species of the gundlachi-group to have been recorded from the U.S.A., where they are apparently restricted to Florida (Brown, 1960a; D. R. Smith, 1979; Deyrup, Johnson, et al., 1989).

Distribution
United States (Florida), Central America, West Indies, and South America.

Distribution based on Regional Taxon Lists
Nearctic Region: United States. Neotropical Region: Barbados, Belize, Bolivia, Brazil, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, Greater Antilles, Guatemala, Haiti, Honduras, Lesser Antilles, Mexico, Paraguay, Peru, Puerto Rico, Saint Lucia, Trinidad and Tobago, Venezuela.



Biology
Deyrup (1997) - Among the snap-trap ants this is an unusually drought-tolerant species that also thrives in disturbed conditions. The queens are often relatively abundant, giving the impression that this species lives in small colonies that produce many new queens that can found new colonies. This would be a useful adaptation for living in frequently disturbed habitats, where occupied nest sites are often destroyed and new ones created.

Brown (1960) - Weber found specimens in a compost heap in the Botanical Garden at Roseau, Dominica, and in an island of vegetation growing in the Pitch Lake of Trinidad; also on Trinidad, he took a sample from low-growing epiphytes in second-growth forest. Kempf sifted specimens from humus in Sao Paulo. Indications are that this species can stand more dryness than many dacetines, and its presence in many culture areas suggests that it is spreading rapidly through nursery stock transport and other human commerce.

Nomenclature

 *  eggersi. Strumigenys eggersi Emery, 1890b: 69, pl. 7, fig. 9 (w.q.) ANTILLES. Combination in S. (Pyramica): Brown, 1948e: 110; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 119. See also: Brown, 1960b: 46; Bolton, 2000: 184.

Worker
Bolton (2000) - TL 1.6 - 2.0, HL 0.40 - 0.45, HW 0.32 - 0.37, CI 81 - 86, ML 0.23 - 0.28, MI 58 - 65, SL 0.20 - 0.24, SI 58 - 64, PW 0.20 - 0.23, AL 0.40 - 0.46 (20 measured). Characters of gundlachi-group; see also notes under Strumigenys gundlachi. Inner margin of mandible feebly convex, with 4 - 8 preapical small denticles on the distal one-third to one-half of the length. Dorsum of pronotum with a single pair of erect hairs (as well as the humeral pair), located on anterior half, usually between the humeral pair. Pair of mesonotal erect hairs short and stiff. On postpetiole ventral spongiform appendage vestigial to absent; lateral lobe absent or at most represented by a narrow marginal non-spongiform carina. First gastral tergite strongly reticulate to reticulate-punctate basally; this sculpture may cover the entire sclerite or tend to diminish in intensity posteriorly.

Type Material
Bolton (2000) - Syntype workers and queens, ANTILLES IS: St Thomas I. (Eggers) [examined].