The invasive Asian longhorned tick (Haemaphysalis longicornis) was first reported on the U.S. East Coast in 2017, yet its regional distribution and potential ecological impacts are still under investigation. This study examined the presence and abundance of H. Longicornis in oak and maple forests across Pennsylvania from May to September 2024. Ticks were sampled biweekly and collected specimens were identified morphologically. Patterns of abundance and community composition were analyzed. H. longicornis exhibited the highest density at site NE16, where overall tick diversity was comparatively low. Seasonal trends revealed nymphal activity peaking in June, followed by a larval surge in late August. These findings highlight the rapid spread of H. longicornis in Pennsylvania ecosystems and raise concerns over its capacity to alter native tick assemblages and pathogen transmission dynamics. Given the species’ role as a competent vector of multiple pathogens, continued surveillance is essential to assess its ecological effects and potential public health implications.