Ticks, chiggers, horn flies, and other external parasites can be reduced with fire. However, studies have shown parasite reductions are generally short-lived with parasites typically returning to pre-burn levels within a couple of seasons.
Relevant literature:
Cully, J. 1999. Lone star tick abundance, fire, and bison grazing in tallgrass prairie. Journal of Range Management 52:139–144.
Drew, M., W. Samuel, G. Lukiwski, and J. Willman. 1985. Evaluation of burning for control of winter ticks (Dermancentor albicuptus) in central Alberta. Journal of Wildlife Diseases 21: 313–315.
Swengal, A. 2001. A literature review of insect responses to fire compared to other conservation managements of open habitat. Biodiversity and Conservation 10:1141–1169.