Effect of deer exclusion by fencing on abundance of Amblyomma americanum (Acari: Ixodidae) on Fire Island, New York, USA

The effects of deer exclusion on northern populations of lone star ticks, Amblyomma americanum, were tested at the Lighthouse Tract, Fire Island, NY, USA, where densities of this species have increased recently. Game fencing was erected to exclude deer from two sites of roughly one ha each, and populations of nymphal and adult A. americanum within were compared with those at control sites outside the exclosures. Percent control of nymphs within vs. outside the exclosures averaged 48.4% in the four years post-treatment, compared to pretreatment values. Percent control varied markedly in different years, suggesting that factors in addition to deer densities had strong effects on population densities of A. americanum. Exclosures of this size did not control adult A. americanum. Effects of deer exclusion in this recently expanded northern population of A. americanum were similar to those that have been reported for southern populations of this species.