Phenology and ecology of tick species parasitic on cattle and wildlife in Oklahoma

Pastured cattle are parasitized by several different species of ticks.  Most of these tick species are capable of transmitting pathogens that impact veterinary and human health. In the United States, limited research has focused on the activity of tick species, specific life stages and abundance of ticks on both cattle and pastureland. Additionally, there is limited information on wildlife hosts, their interactions within cattle pastures, and the effects of wildlife on tick populations within cattle pastures.  The current study is aimed toward identifying tick species free living on pastures and feeding on pastured cattle in cow-calf systems across different ecoregions and in different habitats throughout the year in Oklahoma. Current results show clear differences in the abundance of ticks recovered from pasture and woodland biotopes at each field site as well as differences between the species recovered from cattle and collected in pastures.  Transects just inside the trees in each pasture yielded significantly more ticks than pasture transects. Amblyomma americanum is the primary species recovered from flagging and CO₂ trapping at most of the five field sites. Despite the primarily dry climate, both A. americanum and Dermacentor  variabilis have been abundantly recovered from pasture areas with trees in southwestern Oklahoma. In contrast, parasite numbers on cattle grazing in the same area were low. Understanding the ecology and seasonal fluctuations of tick populations is essential to the development of programs aimed at ectoparasite control and disease prevention.