Relationship between skin-sensitizing antibody production in the eastern cottontail, Sylvilagus floridanus, and infestations by the rabbit tick, Haemaphysalis leporispalustris, and the american dog tick, Dermacentor variabilis (Acari: Ixodidae)

The resistance of cottontails to tick feeding appears to be correlated with the animals' development of skin-sensitizing antibodies. Cottontails and rabbits developed a detectable resistance response after the 2nd tick infestation, and resistance was strongest after the 5th infestation. Duration of the resistance response was tested after allowing the animals to rest for 6 weeks, and the results indicated that resistance was still evident but at reduced levels. A study of cross-resistance was also made in which 1/2 of the animals resistant to the rabbit tick, H. leporispalustris , were reinfested with H. leporispalustris and the other 1/2 were infested with the American dog tick, D. variabilis . There were no significant differences between numbers of replete nymphs or Prausnitz-Kuestner (P-K) scores regardless of the tick species used. This research supports the hypothesis that resistance may function as a homeostatic regulatory mechanism, which maintains the size of the parasite population in equilibrium with that of the host population.