Solenopsis nickersoni

Solenopsis nickersoni was collected by subterranean trap at Gainesville Airport, Florida (Thompson 1989). Additionally, this species can be found in Oak Hickory scrub in Florida.

Identification
A New World thief ant that is a member of the molesta species complex. (Key to New World Solenopsis Species Complexes)

Pacheco and Mackay (2013) – Worker - This is a small, medium brown ant with pale yellow legs and antennae. There are suberect hairs on the head that are pointing to the midline of the head. The lateral clypeal teeth are well developed and the extralateral teeth are absent. All body surfaces are smooth and shiny. Both the petiolar peduncle and postpetiole are lacking a tooth are flange ventrally.

Solenopsis nickersoni is essentially identical to Solenopsis castor, differing only in being slightly smaller. It will continue to be considered a valid species until the female can be compared with the female of S. castor. It can be easily separated at the present time, as it occurs in Florida, whereas S. castor is not known from Florida, although it occurs nearby in the Antilles Islands and in Mexico south to Bolivia It would be unlikely that this species would be confused with any others in Florida, based on the color.

Thompson (1989) - Queen easily separated from most other dark Florida thief ant females (abdita, picta, tonsa) by the dusky wings. If wingless, it can be separated from all the dark species by its much greater size which is easily determined by utilizing Weber's measurement of thorax length.

Distribution
Florida.

Distribution based on Regional Taxon Lists
Nearctic Region: United States.

Biology
Thompson (1989) - Mating flights probably occur in midsummer since 2 winged specimens in my collection are labeled 2 July. I have never collected a colony in the field and the sexual forms are not attracted to lights.

Castes
Males have yet to be collected.

Nomenclature

 *  nickersoni. Solenopsis (Diplorhoptrum) nickersoni Thompson, 1982: 486, fig. 1 (w.) U.S.A. Thompson, 1989: 281 (q.).

Worker
Pacheco and Mackay (2013) - (n=5). TL 1.14-1.50 (1.34); HL 0.390-0.408 (0.394); HW 0.312-0.336 (0.323); EL 0.036-0.042 (0.037); ED 0.030-0.036 (0.031); SL 0.252-0.288 (0.265); FSL 0.102-0.120 (0.109); CI 79.4-86.2 (82.0); SI 64.6-70.6 (67.3); PL 0.060; PW 0.084-0.090 (0.089); PI 66.7-71.4 (67.6); PPL 0.078-0.102 (0.092); PPW 0.108-0.120 (0.115); PPI 72.2-85.0 (80.0); WL 0.276-0.300 (0.288); PSL 0.024-0.030 (0.029); PSW 0.024-0.030 (0.029).

Small, medium brown, with pale appendages; head quadrate, longer than wide; clypeallateral teeth well developed, extralateral teeth absent; clypeal carinae well defined; frontal lobes vertically striated; scape long, reaching ¾ length of head to posterior lateral corner; eyes small, five ommatidia; mesosoma smooth and shiny; posterior propodeal margin rounded; petiole wider than postpetiole viewed laterally; petiolar node rounded triangular, peduncle without tooth or flange ventrally; postpetiolar node oval viewed laterally.

Moderately hairy, yellow pilosity; erect and suberect hairs of various lengths covering all body surfaces; suberect hairs on head pointed to midline of head; suberect hairs of arious lengths on mesosoma (longest 0.120 mm); suberect hairs on petiole and postpetiole curve posteriorly.

Queen
Thompson (1989) - HL 0.60-0.64; HW 0.60-0.65; CI 97-104; SL 0.38-0.12; SI 64-68; EL 0.18-0.19; WL 1.16-1.22; HTL 1.76-1.86 (N = 6 from Highlands, Levy and Marion counties).

Structural Characters—Head nearly square, narrowing slightly in front of the eyes, the posterior border slightly excised in the center. Eyes large and nearly circular. Area enclosed by the prominent ocelli is much darker than remainder of the head. Scapes not quite reaching hind corners of head.

Promesonotum of thorax weakly convex in profile, dorsum of propodeum slightly more convex. Thorax almost perfectly oval from above. Transcutal suture smoothly rounded. Petiole and postpetiole without prominent teeth or swellings. Postpetiole nearly circular, from above, and slightly wider than petiole while petiole has a slight indentation of the median dorsal border.

Sculpture—All surfaces smooth and shining except for numerous piligerous punctures. Punctures most numerous on dorsum of gaster. Posterior lower half of propodeum; upper 2/3 of petiole and all of postpetiole covered with punctations and slight striation.

Pilosity—Entire body covered with thick-looking clear suberect hairs. Hairs arise from punctures and are most numerous on dorsum of head, thorax and gaster.

Color—Entirely medium reddish-brown with dusky wings.

Type Material
Pacheco and Mackay (2013) - Florida, Alachua. Co., Gainesville Airport, 7-x-1979, Trap 53, Col. C. R. Thompson, Thompson 1982 (3 paratype workers [seen] ).

References based on Global Ant Biodiversity Informatics

 * Annotated Ant Species List Ordway-Swisher Biological Station. Downloaded at http://ordway-swisher.ufl.edu/species/os-hymenoptera.htm on 5th Oct 2010.
 * Deyrup M., C. Johnson, G. C. Wheeler, J. Wheeler. 1989. A preliminary list of the ants of Florida. Florida Entomologist 72: 91-101
 * Deyrup M., L. Deyrup, and J. Carrel. 2013. Ant Species in the Diet of a Florida Population of Eastern Narrow-Mouthed Toads, Gastrophryne carolinensis. Southeastern Naturalist 12(2): 367-378.
 * Deyrup, M. 2003. An updated list of Florida ants (Hymenoptera: Formicidae). Florida Entomologist 86(1):43-48.
 * Deyrup, M. and J. Trager. 1986. Ants of the Archbold Biological Station, Highlands County, Florida (Hymenoptera: Formicidae). Florida Entomologist 69(1):206-228
 * Johnson C. 1986. A north Florida ant fauna (Hymenoptera: Formicidae). Insecta Mundi 1: 243-246
 * King J. R. 2007. Patterns of co-occurrence and body size overlap among ants in Florida's upland ecosystems. Ann. Zool. Fennici. 44: 189-201
 * Pacheco J. A., and W. P. Mackay. 2013. The systematics and biology of the New World thief ants of the genus Solenopsis (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 501 pp.
 * Thompson C. R. 1989. The thief ants, Solenopsis molesta group, of Florida (Hymenoptera: Formicidae). Florida Entomologist 72: 268-283