Aphaenogaster floridana

This species nests in sandy soil, with the nest being at least 80 cm deep. Nest entrances are often hidden with plant debris. Nests may be small, with fewer than 50 workers and apparently have a single queen.

Identification
The scape of the worker of this species extends about three funicular segments past the posterior lateral corner. The base of the scape is enlarged into a lobe. The dorsum of the pronotum is finely sculptured, but smooth and glossy, and the propodeum lacks spines (tiny angles may be present).

The scape other female is similar to that of the worker, surprisingly, the propodeum has well-developed spines. The pronotum is transversely striate, and only weakly shining.

It would be unlikely to confuse the workers of this species with any of the others, due to the unusual structure of the base of the scapes and the lack of propodeal spines.

Aphaenogaster floridana is one of the NA Aphaenogaster species without propodeal spines. The gaster is not significantly darker than the head and mesosoma (compared to Aphaenogaster boulderensis). They are found in sandy pine scrub and mixed hardwood forest. (DeMarco, 2015)

Florida
Deyrup (2016) - This is a yellow species with an arrowhead-shaped base on the antennal scape, but its most distinctive feature is the absence of propodeal spines, which are well developed in all other Florida species of Aphaenogaster.

Florida
Deyrup (2016) - North Carolina south into Florida, west along the Gulf Coastal Plain into Alabama. In Florida, floridana is relatively common in uplands through north Florida, much rarer to the south, although it has been found on the Lake Wales Ridge in Highlands County.

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

Biology
Found in pine savannahs, longleaf pine, turkey oak forests, open shrubby habitats and sparse grassy habitats.

Florida
Deyrup (2016) - The following paragraph is summarized from Carroll (1975). Nests are in well-drained, sandy soil in open areas such as fields, sandhills, or Florida scrub habitats. There are usually one or two nest entrances, sometimes with a short turret of plant debris and arthropod remains, and often situated at the base of a clump of grass. The main entrance may be changed every few days or weeks. Nests are deeper than those of other Florida Aphaenogaster, sometimes 1.3 meters deep. Foraging is on the ground, crepuscular or nocturnal during warm weather. Foragers collect various arthropods, including Pheidole morrisii, and alate dispersing Solenopsis invicta and Solenopsis geminata. This species collects seeds of the hemiparasitic plant Seymeria pectinata, and pieces of Russula mushrooms. Alates are in the nest from late June and early July, and may be seen at nest entrances in late August and early September. The largest colony seen had approximately 200 workers.

In North Carolina, Carter (1962) found floridana on the Coastal Plain in grassy, open sandhill areas, and similar habitats, including grassy depressions between coastal dunes. In Florida, Van Pelt (1958) found floridana in open sandhill areas and open, sandy roadsides. He states that most foraging is nocturnal or on cloudy days.

Lack of Propodeal Spines
Deyrup (2016) - Propodeal spines are lacking in this species, while they are well developed in all other Florida species of Aphaenogaster. Males and queens have small spines, suggesting that the loss of spines in the worker is a recent evolutionary event. The adaptive significance of this is unknown, but two other Florida ants of open, sandy areas, Pogonomyrmex badius and Pheidole morrisii, also seem to have recently dispensed with propodeal spines, although they occasionally appear in P. badius. The primary function of the propodeal spines is to protect the vulnerable petiolar joint, best achieved by raising the petiole so that it rests between the petiolar spines. This is probably most useful for species that grapple and sting, and would not be as useful for species that spray repellents. Three possible hypotheses explaining the loss of propodeal spines in floridana are as follows: this species uses another form of defense, such as powerful chemical deterrents; this species has a way of avoiding grappling encounters; this species lives in a habitat where most competitive, aggressive, or defensive encounters are with other ants that spray repellent chemicals.

Nomenclature

 *  floridana. Aphaenogaster (Attomyrma) floridana Smith, M.R. 1941: 118 (w.) U.S.A.
 * Wheeler, G.C. & Wheeler, J. 1960b: 7 (l.).