Ixodid ticks on feral swine in Florida.

More than 99% of the 645 feral swine (Sus scrofa L.) in southern Florida harbored ixodid ticks. Dermacentor variabilis (American dog tick) was present on 99.6% of the swine and comprised 82.5% of the ticks collected. Amblyomma maculatum (Gulf Coast tick) occurred on 85.9% of the hosts and 17.4% of the collections were of this species. Amblyomma americanum (Lone Star tick) and Ixodes scapularis (Black-legged tick) were found infrequently and together constituted less than 0.1% of the ticks. Pigs were infested by 7-22 days of age and 95% carried ticks by 6 wk of age. Only adult ticks were found on swine from southern Florida, but immature stages of A. americanum were present from a small sample of swine from northern Florida. Each species had a different pattern of distribution on the feral swine. No Ornithodoros species were found among the 36,616 ticks collected from feral swine during this survey.