Is tick season worse this year in Pennsylvania? Here’s what experts say
AI-generated summary reviewed by our newsroom.
- Native and new ticks, including the lone star tick, are expanding in the Northeast.
- Tickborne illnesses like Lyme and alpha-gal syndrome, a red meat allergy, are on the rise.
- But tools like DEET, permethrin and a frequent tick checks help keep you safe.
Pennsylvania scientists, hikers and even the governor are talking ticks.
Complaints about ticks in Pennsylvania spike in June and July, when cases of Lyme rise. Some who’ve spent time outdoors this summer say tick season is worse than ever. Meanwhile, Penn State entomologist Erika Machtinger and her research team have found fewer ticks in central Pennsylvania than in previous summers. And on Monday, officials from Gov. Josh Shapiro’s administration visited Samuel S. Park in York County, where they urged people to protect themselves from ticks without sacrificing time outside.
Ticks, which can transmit Lyme and other diseases, abound in some areas of Pennsylvania and seem absent in others.
“What people are experiencing in their backyard may be very different from what someone sees just a county away,” Machtinger wrote in an email to the CDT.
That said, native tick species are spreading into new regions as new species inch north. Lone star ticks, though not new to Pennsylvania, are becoming more numerous. Tick-borne illnesses like Lyme are on the rise, too. In Pennsylvania, a top state for Lyme, there were more than 16,600 cases in 2024, up from just 30 in 1985, according to data from the Pennsylvania Department of Health.
That data also showed that Centre County had 11 reported cases of Lyme this year, which is fewer than most other counties in the state. Allegheny, meanwhile, had 511. But Centre County has had 46 cases of anaplasmosis, another disease spread by ticks, which is higher than most other counties.
The surest way to avoid illnesses like Lyme and alpha-gal, the meat allergy lone star ticks can trigger, is to avoid ticks in the first place. Experts recommend wearing clothing treated with permethrin, which targets ticks before they attach. DEET and other EPA-registered repellents help. Machingter advises people to make a habit of tick checks, and not just at home. “Even a quick sweep over your clothing” while outside, she wrote, can help avoid a bite. Pet owners should protect their animals, too.
Tick season, though worse in recent decades, is not new. Early colonization, which led to deforestation, helped make the Northeast a hotbed for ticks. And the removal of large predators like mountain lions helped small critters, ideal hosts for ticks, flourish. Deer have made a comeback, too, facing few threats other than cars. Meanwhile, climate change has disrupted seasonal patterns, pushing tick season earlier.
“This is not a tick problem that came out of nowhere,” Machtinger wrote. “In many ways, this is a situation that has been centuries in the making.”
Among at least 25 species of ticks in Pennsylvania, two kinds–backlegged and American dog ticks–are most common. Also called “deer ticks,” backlegged ticks most often contract Lyme early in life, as larvae or nymphs, after feeding on an infected host. No bigger than a sesame seed, backlegged nymphs become sneaky agents of transmission.
While backlegged ticks wait passively on plants for hosts to sweep them up, lone star ticks are aggressive biters. They seek out hosts — humans, livestock, horses and pets — and latch on. But lone star ticks, which have expanded in the Northeast, may be easier to spot. A female adult has a white spot on her back, the “lone star” namesake, and males are mostly reddish-brown.
DEET, permethrin and high-coverage clothes can keep ticks from biting. But even the best methods sometimes fail. Machtinger says people should remove ticks as soon as possible after they bite, holding tweezers or fingers close to the skin before tugging the tick straight out. She recommends tracing the bite with a marker to help monitor any changes.
Ticks, even in urban settings, are a risk. Resources like Penn State Extension, where readers can learn more about ticks and the threats they pose, can help keep people safe. On the Department of Health website, readers can find information about all things tick: where they abound, how to avoid them and what to do when bitten.
“The goal is not to make people afraid to go outside,” wrote Machtinger. “The goal is to give people practical tools to reduce their risk.”
