A simulation-model for genetic-resistance to acaricides in the African brown ear tick, Rhipicephalus appendiculatus (Acarina: Ixodidae)

Network representations and computer modelling techniques were used to develop a framework in which to investigate the relationship between tick resistance to acaricides and genetic fitness. The computer model simulated the day-to-day occurrences experienced by ticks and allowed constants relating to the efficacy of acaricide dipping, and survival and development of the tick, in different stages, to be varied. Results are presented on the mean number of years taken for resistance to appear in a population of Rhipicephalus appendiculatus, maintained under climatic conditions similar to those experienced by ticks in the highlands of Kenya. The computer model which was employed also made it possible to study chemical resistance in other parasite systems, by changing constants regarding the species and the nature of the chemical control.