Seasonal Activity, Density, and Collection Efficiency of the Blacklegged Tick (Ixodes scapularis) (Acari: Ixodidae) in Mid-Western Pennsylvania.
Although Pennsylvania has recently reported the greatest number of Lyme disease cases in the United States, with the largest increase for PA occurring in its western region, the population biology of the blacklegged tick (Ixodes scapularis Say) has not been adequately characterized in western PA. We studied the seasonal activity of host-seeking I. scapularis larvae, nymphs, and adults in mid-western PA over the course of a year, including a severe winter, and determined their absolute densities and collection efficiencies using replicated mark-release-recapture or removal methods. Our results are compared to those from similar studies conducted in the highly Lyme disease endemic Hudson Valley region of southeastern New York State. The seasonal activity of I. scapularis was intermediate between patterns observed in the coastal northeastern and upper Midwestern United States. Only one peak of larval activity was observed, which was later than the major peak in the Midwest, but earlier than in the northeast. Seasonal synchrony of larvae and nymphs was similar to the northeast, but the activity peaks were much closer together, although not completely overlapping as in the Midwest. Pre- and postwinter relative densities of questing adult I. scapularis were not significantly different from one another. The absolute densities and collection efficiencies of larvae, nymphs, and adults were comparable to results from classic research conducted at the Louis Calder Center in Westchester County, NY. We conclude that the population biology of I. scapularis in mid-western PA is similar to southeastern NYS contributing to a high acarological Lyme disease risk.
Department of Biology, 114 Weyandt Hall, 975 Oakland Avenue, Indiana University of Pennsylvania, Indiana, PA 15705. tsimmons@iup.edu.
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Simmons
Department of Biology, 114 Weyandt Hall, 975 Oakland Avenue, Indiana University of Pennsylvania, Indiana, PA 15705.
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Shea
Department of Biology, 114 Weyandt Hall, 975 Oakland Avenue, Indiana University of Pennsylvania, Indiana, PA 15705. Current address: Pennsylvania Highlands Community College, 101 Community College Way, Johnstown, PA 15904.
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Myers-Claypole
Department of Biology, 114 Weyandt Hall, 975 Oakland Avenue, Indiana University of Pennsylvania, Indiana, PA 15705.
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Kruise
Pennsylvania Department of Environmental Protection, P.O. Box 1467, Harrisburg, PA 17105.
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Hutchinson
D000818:Animals; D005843:Geography; D018884:Ixodes; D010414:Pennsylvania; D011156:Population Density; D012621:Seasons
Ixodes scapularis; Pennsylvania; blacklegged tick; density; seasonal activity