More than 100 years of historical data show shifting tick populations

Image credit: Bigstock

Image credit: Bigstock


How can we predict new or emerging tickborne diseases?

  • The blacklegged tick (deer tick) is the most prevalent species in the eastern United States.
  • As the primary vector of Lyme disease, the deer tick is currently the biggest threat.


Entomologists studied data collected over the past 117 years to track shifts in the dominant species of ticks in Pennsylvania.

  • The team compiled data from more than 7,000 tick specimens collected at Penn State since 1900.
  • The changes correlate with climate changes and variability, shifts in land use that led to habitat loss and fragmentation, and changes in human or animal behavior that brought ticks and their hosts in closer proximity.


Combining robust surveillance with analysis of historical data helps public health officials and researchers identify high-risk areas, discover ecological trends, and develop predictive models for assessing the risk of tickborne diseases.

Research Area: Integrated Health Solutions

Research Credit


Participating Departments

Competitive Funding

  • National Science Foundation; Penn State College of Agricultural Sciences; Huck Institutes of the Life Sciences

Federal and State Appropriations

  • USDA NIFA Hatch Project PEN04608, Accession #1010032

Emerging Discoveries

Published Research

A 117-year retrospective analysis of Pennsylvania tick community dynamics