Frequency and Distribution of Polygyne Fire Ants (Hymenoptera: Formicidae) in Florida

Abstract

In order to determine the frequency and distribution of polygyne and monogyne fire ants (Solenopsis invicta) in Florida, preselected sites were surveyed from Key West to Tallahassee. Polygyne colonies were found at 15% of infested sites--a frequency similar to other states in the southeastern United States, but much less than in Texas. Polygyny was most common in the region around Marion county, but smaller populations were also scattered across the state. The density of mounds at polygyne sites was more than twice that at monogyne sites (262 versus 115 mounds/ha), although mound diameters were about 20% smaller. Polygyne and monogyne queens averaged the same size (1.42 mm, head width), but monogyne queens were much heavier (24.3 mg versus 14.4 mg) due to their physogastry. As expected, workers in polygyne colonies were considerably smaller than those in monogyne colonies (0.28 mg versus 0.19 mg, dry fat-free).