Influence of prescribed burns on the abundance of Amblyomma americanum (Acari: Ixodidae) in the Missouri Ozarks.

The increasingly widespread use of prescribed burns to manage oak (Quercus spp.)-hickory (Carya spp.) forests in the Missouri Ozarks, USA, has considerable potential to alter the abundance of Amblyomma americanum (L.) (Acari: Ixodidae), the lone star tick, an important vector of several emerging pathogens. In particular, responses of important tick hosts, primarily white-tailed deer (Odocoileus virginianus), to fire management and the resultant changes in the distribution and abundance of A. americanum are largely unknown. Using several large burn units (61-242 ha) within the Ozark ecosystem, I measured the effect of the time elapsed since sites were burned on the density of white-tailed deer and the larval life stage of A. americanum. Larval tick densities were highest in areas that were 2 yr postburn and were > 6 times higher than tick densities in control units. Deer densities were highest in sites that were burned in the same year as this study and decreased significantly with time since burn. These results suggest that intensive use of postburn sites by white-tailed deer may increase the abundance of A. americanum to levels greater than occurs in sites that remain unburned. Thus, fire management, although beneficial in many aspects of ecosystem management, may bear the unintended cost of locally increasing abundance of A. americanum.