Effects of red imported fire ants (Solenopsis invicta) and habitat on the survival of lone star ticks (Amblyomma americanum) and gulf coast ticks (Amblyomma maculatum)

Identifying ways in which humans can reduce tick populations will be important in preventing the spread and emergence of disease in the future. In a study determining the effects of long-term prescribed burning on ticks in Georgia, both a reduction in ticks as well as a shift in species composition was observed with the lone star tick (Amblyomma americanum) preferring unburned habitats and the Gulf Coast tick (A. maculatum) preferring burned habitats. Interestingly, the red imported fire ant (Solenopsis invicta) is found predominantly in disturbed habitats, such as burned habitat, and several studies have reported that A. americanum is preyed upon by S. invicta. To better understand the drivers of tick population changes in burned habitat, the current study was conducted to evaluate the effects of S. invicta and habitat on survival of A. americanum and A. maculatum. Within treatments (burned habitat with ants, burned habitat without ants, and unburned habitat without ants), 10 tick enclosures were installed and seeded with engorged A. americanum and A. maculatum nymphs. Ticks were introduced during months of peak activity for that species. After molting, all ticks were collected. Survival of A. americanum in burned habitats (regardless of ant presence) was significantly lower compared with unburned habitat. A. maculatum had significantly higher survival in burned habitats (regardless of ant presence) compared to A. americanum.  These results indicate that burning drives tick population dynamics, not S. invicta, with A. maculatum being better adapted to survive in burned habitat which experiences higher temperatures and lower humidity.