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The Florida harvester ant, Pogonomyrmex badius, is the only of the 22 species of harvester ants (Pogonomyrmex) that occur east of the Mississippi river. It is native to the Gulf coastal plain from Mississippi to Florida, and the Atlantic coastal plain north to North Carolina. While found in abundance across their range, they are patchily distributed because Florida harvester ants only nest in dry sand habitats in open areas. Dry hammocks in open woodlands or grassy areas are especially preferred. They also regularly build nests on lawns, around gardens, and in fire lanes.
Florida harvester ants are dark rusty red in color. Like other members of its genus, Florida harvester ants have a beard-like row of hairs on the under side of its head. Colonies include several castes of workers, whose sizes vary from 0.6-1 cm (0.25 - 0.4 inches) long. The soldiers are the largest workers, and are also characterized by having disproportionately large heads. Each colony has a single, long-lived queen. Colonies have been recorded as lasting for more than 19 years. Workers are most active in dry heat (35-40oC, or 95-105oF) and build nests in unshaded areas. Rains in June-October precipitate mating swarms in which winged reproductive individuals leave the nest to mate with females. Mated females then form a new colony, and the winged males die.
Florida harvester ants excavate nests, which delve down to 6 feet (2 meters) deep, in sandy soils. A nest has one or more entrances in the center of a slight mound 30 - 60 cm (1-2 feet) in diameter, and many underground tunnels and chambers. The mound is a cleared area, so readily visible. It is often covered with small pebbles, middens from seed chaff and other waste, and charcoal from burned areas. Experimental work has shown the charcoal pieces to function as territorial markers that drive away invading aggressor ants of other species.
Like other harvester ants, P. badius collects seeds for food and stores them in grain chambers in the nest to eat later. Workers gather seeds of many different plants, including ragweed, crab grass, small crab grass, rough buttonweed, sedge, Paspalium sp., poke weed, red clover, alfalfa, evening primrose, narrow leaf vetch and crotonweed. The ants will take seeds that have fallen to the ground, and will also harvest seeds growing on the plant. Workers lay down odor trails to mark paths to food sources.
Florida harvester ant colonies construct and move into a new nest about once a year. Often the move is motivated by encroachment of vegetation which shades the old nest, or by aggressors from other ant colonies (both the same and different species) that drive a colony to a different location.
While Florida harvester ants are not at all aggressive towards and rarely sting humans. However, they produce a very toxic venom so when they do sting, it is one of the most painful and long-lasting of any ant species. Florida harvester ants are sometimes considered agricultural pests, causing damage to agricultural crops through their seed harvesting behaviors.
(Gordon 1984; Harrison and Gentry 1981; Klotz et al. 2005; Nickerson and Fasulo, 2013; Tschinkel 2014)