Effects of fire management on the abundance of Amblyomma americanum (Acari: Ixodidae) in the Missouri Ozarks

Amblyomma americanum (the lone star tick) is an important vector of several emerging infectious diseases in the eastern and central United States.  Anthropogenic activities that influence the abundance of A. americanum require additional investigation, since factors that alter tick abundance may influence human rates of exposure to tick-borne pathogens.  The Ozark Ecosystem of southern Missouri is becoming increasingly managed by prescribed burns on both state and federal forested lands.  While the extensive use of fire management is believed to benefit native species and reduce fuel loads, the impacts of fire management on A. americanum have not been explored.  In the summer of 2006 I sampled 12 fire-managed compartments in four age classes of time since burn: 0, 2, 4, and 10+ years.  I established four, 100 meter transects in each compartment and measured the density of larval ticks using the drag-sampling method.  Dung-cluster surveys were performed along the same transects to determine the density of white-tailed deer, and temperature and humidity data were measured at each site using LogTag data loggers.  The survey results indicate that the abundance of A. americanum increases substantially in the time periods immediately following a prescribed burn, and then drop to pre-burn levels in the later age classes.  These changes in tick abundance appear to be driven by the positive response of white-tailed deer to fire management.  These results suggest that fire management may increase the abundance of A. americanum in managed areas and that further exploration of burn intervals and intensity is warranted.