Mapping European deer ked (Diptera: Hippoboscidae) abundance across Pennsylvania using traditional and citizen science methods

European deer keds (Diptera: Hippoboscidae: Lipoptena cervi (Linnaeus, 1758)) are blood-feeding ectoparasitic flies that usually feed on deer and other cervids but sometimes bite humans. Introduced into North America in the late 1800s, they have since become widespread in the Northeast. European deer keds were historically reported at the regional or state level, but recent work has begun to clarify their range by compiling county-level occurrence data. We expand upon this trend by using multiple methods to determine where deer keds are relatively more and less abundant in Pennsylvania. Based on our results, European deer keds are most abundant in northern Pennsylvania, present but less abundant in central and western Pennsylvania, and absent or nearly so from southeastern counties. Understanding where deer keds occur will inform public education and allow the public to better protect themselves from deer ked bites.