Movement of Male Dermacentor andersoni (Acari: Ixodidae) Among Cattle

Movement of male Dermacentor andersoni (Stiles) was examined among 54 pairs of artificially infested donor and recipient cattle during a 3-yr period. The number of males declined at a rate independent of the initial level of infestation, while the rate of decline of females on the donor animals tended to increase with initial infestation level. Male tick movement to recipient cattle was observed in 26 of 54 (48%) of the animal pairs, but varied among years and trials. Movement tended to be greater during April compared with May and June. The daily probability of movement averaged (SD) 0.067 (0.082), and the number of males moving per day averaged (SD) 0.083 (0.228). Logistic and Poisson regression models were developed and indicated that movement was determined by interactions between the number of males on the donor animals, differences in the number of females on the donor and recipient cattle, temperature, and female age. These models can be used to incorporate movement into tick population models.