Army Ant Encounter
by
Zach Prusack

     Observing army ant raiding behavior is always a treat, especially in Florida. I was inspecting fire lines on August 13th for an upcoming prescribed fire within the Malabar Scrub Sanctuary, Brevard County Florida. This 400-acre site is comprised of scrubby flatwoods, sand pine scrub and mesic flatwoods…all fire-dependant habitats and full of neat ants. Heavy rains (over three inches in two days) left much of the scrubby flatwoods saturated, so the ant activity at the surface was subdued this morning. At approximately 9:00 am, two lines of scurrying ants caught my eye……they were Pheidole morrisii, a medium-sized yellowish-brown Pheidole common in Florida. Two lines of ants were rapidly leaving a large nest built under a saw palmetto (Seranoa repens), about a third of them carrying larvae and pupae. One line was heading for a small log about fifteen feet away, while the other line was heading for what appeared to be another nest entrance about four feet away in a patch of wiregrass (Aristida beyrichiana). When I turned the log over, I could see the Pheidole massing in a hollow portion of the log with all of the transported brood. Well, all of this activity probably meant that an army ant raid was under way, but how to locate these subterranean beasts? Upon closer inspection at the base of the large nest, two Neivamyrmex opacithorax were found to be slowly flailing about on the soil….these ants were missing most of their legs! I then dug down about a foot deep at the base of the saw palmetto directly under these dismembered ants, and sure enough found the remnant of a raiding column which consisted of about a dozen Neivamyrmex and several Pheidole as well. Out of these dozen Neivamyrmex collected in the soil, 10 had at least two legs removed at the femur, and two ants had five legs removed. One was missing both its antenna and gaster, and one had the head of a Pheidole major firmly wrapped around a leg! While it was evident that most of the Pheidole grabbed their brood and headed for the hills, some stayed to fight underground. Another neat find were two Hypoponera inexorata that were collected right along with the army ants in the same pile of excavated soil…I didn't realize I had collected these ants until mounting them up later, they looked very similar in the field.