Introduction, spread and subsequent disappearance of the brown ear-tick, Rhipicephalus appendiculatus, from the southern lowveld of Zimbabwe.

According to the climate-matching model CLIMEX the hot, dry lowveld of Zimbabwe is unsuitable for the survival of the brown ear-tick Rhipicephalus appendiculatus. There is evidence that the tick was absent from the lowveld in the 1960s but was introduced in 1973 and spread over a large area before disappearing in 1983. It was introduced at the start of a wet cycle when, according to CLIMEX predictions, conditions were suitable for its survival, and it disappeared at the end of a dry cycle when conditions were unsuitable. The most important factor in the disappearance of the tick appeared to be heat stress. The study has provided an illustration of the dynamic distribution of R. appendiculatus and field validation of the CLIMEX model.