Scrub Hub: Are ticks across Indiana getting worse? Should Hoosiers be worried?
I’m roughly the size of a sesame seed when full grown. I am not an insect, but rather a relative of the spider. Oh yeah, and I want to suck your blood.
What am I?
If you guessed a tick, you would be correct.
You may notice a bit of a trend: The last edition of the Scrub Hub was about mosquitoes while this installment will focus on another summer pest that can be equally annoying and dangerous — though potentially harder to detect.
Mosquitoes at least announce themselves before making you their prey with their incessant high-pitched buzzing and that prickling itch when they bite. Ticks, on the other hand, are silent stalkers that actually secrete a chemical in their bite so you won’t even know they’ve latched on.
It's tick season: Here are tips to protect against the blood-sucking bugs
As Hoosiers take to parks, trails and camping grounds for some respite in the great outdoors, many may have an unknown and unwanted hiking buddy in the tick. We’ve been hearing from a lot of you in posts on social media or questions sent our way that the ticks this year seem particularly bad and worse than normal.
We wanted to see if that was, in fact, the case. So for this Scrub Hub, we are answering the questions: Are ticks getting worse in Indiana? What’s causing it?
To get those answers, we spoke with some experts in entomology — bug buffs — to figure out the status of ticks in Indiana and how are they changing.
Short answer: Tick encounters on the rise
Are ticks in fact getting worse? That’s hard to say, and depends how you measure it.
Since 2004, the number of total reported cases of tickborne disease across the country has steadily increased, according to the U.S. Centers for Disease Control and Prevention. In 2004, there were more than 22,000 reported cases and by 2019, that number had grown to more than 50,000.
While there are more reported diseases, the experts say it’s unclear what’s causing it.
“It’s not clear if there is an increase in ticks and exposure to ticks, or an increase in awareness about ticks and the diseases they cause,” said Jim Fredericks, the chief entomologist with the National Pest Management Association.
Scrub Hub: What is mosquito control, and does it hurt the environment?
He said an increase in awareness is a good thing “because ticks and tick bites often go undetected, and they’re the most common way” people in the U.S. are exposed to vector-borne illnesses, or those transmitted from blood-feeding bugs.
There are three species of ticks that are common in Indiana, and they are capable of transmitting at least nine different pathogens, according to Catherine Hill, a Purdue University professor of entomology and vector biology.
The first is the black-legged or deer tick, which Hill describes as “public enemy No. 1.” This is the tick responsible for Lyme disease and can be found all across Indiana. There are more than 100 cases of Lyme disease reported in the state every year.
The second species Hill watches for in Indiana is the lone-star tick, with a big white dot on its back (hence the name). This is an aggressive tick that is more common in the southern parts of Indiana, and its bite has been linked to triggering alpha-gal syndrome, or an allergy to red meat.
The last type are the American dog and brown dog ticks, which are all over the state, Hill said, and can transmit Rocky Mountain spotted fever. A few dozen cases of the disease are reported in Indiana every year, according to data.
Every year Purdue, as well as other universities and agencies across the state and country, are doing surveillance and watching for ticks, Hill said.
“It’s a really common question: Are we seeing more ticks?” she said “But that’s really hard to answer, because we don’t have a good baseline to measure from.”
Long answer: Climate change expanding tick ranges
Though it’s hard to speak to the actual number of ticks and whether there are more of them, Hill said there are suggestions that people are having more and more tick encounters.
Even more, people are wondering if that rise in encounters is related to a changing climate, she said. And in a way, the answer is yes.
The increase in human-tick encounters is coming from changes to where ticks are found as well as when they are active.
The geographic ranges for ticks are growing and spreading as we see warmer temperatures and more rains or humidity — which are necessary conditions for ticks.
Some research shows that over the past decade or so, the northern edge of where the deer tick — or the tick carrying Lyme disease — has been found has continued to expand north “in parts of Canada where it hasn’t previously been detected,” according to Fredericks with the NPMA.
That 2017 study found a “strong correlation between rising winter temperatures and the spread of the tick population.” While the deer tick was first discovered on the shores of Lake Erie in the 1990s, it has since spread farther north into Ontario and parts of Manitoba, Quebec and Nova Scotia.
As ticks expand their range, that also means we are likely to see new species of ticks from farther south coming up into Indiana, Hill said.
Scrub Hub: Is climate change making Indianapolis' pothole problems even worse?
There are two types of what Hill calls “invasive” ticks that are currently knocking on Indiana’s door. The first is the Gulf Coast tick, which has been common in the southeast and Atlantic states. There are reports it’s been seen in Indiana in recent years.
The other species is the Asian longhorned tick, which was detected in Kentucky last year. Both of these ticks can transmit a number of diseases, and the latter has the potential to impact animal reproductive systems, Hill said.
That could create a big problem for the dairy and livestock industries in the state, as science currently lacks good tools to control ticks on animals and cattle, according to the Purdue professor.
Not only are ticks expanding their range, but they also are more active for longer times of the year.
With warmer temperatures coming sooner and hanging around longer — the loss of the shoulder season, as many call it — ticks similarly are making their debut earlier in the year and then staying later.
That’s also why reported tick bites in the winter are becoming more common. While bites are still rare compared to the summer months, they are not impossible and still pose a risk. Ticks will be out and looking for a meal just about anytime the weather is above 50 degrees Fahrenheit, Fredericks said.
“If you have an extended warm season, that’s when ticks will be most active,” he said, “and that’s when people are most active, too.”
Some initial research from the Purdue Climate Change Research Center suggests that the warming temperatures could indeed increase the actual number of ticks by boosting their reproduction rates.
Between expanded ranges, greater activity and potentially boosted reproduction — ticks are posing a growing problem.
“As our risk of tick encounters increases over the state or throughout different times of the year, our risk of exposure and potential to contract a disease increases,” Hill said.
Both Hill and Fredericks said that people shouldn’t be discouraged from going outside, but there are steps they can take to protect themselves from ticks.
Additional research on how tick populations are changing and what climate change has to do with it is underway. One of the first steps is establishing a baseline, Hill said, to understand what experts are seeing overtime.
She said it will take years to do that, and all Hoosiers can help. Purdue has started a statewide surveillance program in which people can send in ticks they’ve collected along with information about when and where it was found. For more information: tickinsiders.org
This helps Hill and her team continue to build out their foundation of tick research and add to a map about the types of tick encounters around the state.
“We know a lot of things about ticks in Indiana,” she said, “but there is still more to learn.”
If you have more questions about climate and pests, or any other topics, let us know! You can ask us by submitting a question through our Google form below.
Can’t see the form? Click here.
Call IndyStar reporter Sarah Bowman at 317-444-6129 or email at sarah.bowman@indystar.com. Follow her on Twitter and Facebook: @IndyStarSarah. Connect with IndyStar’s environmental reporters: Join The Scrub on Facebook.
IndyStar's environmental reporting project is made possible through the generous support of the nonprofit Nina Mason Pulliam Charitable Trust.
This article originally appeared on Indianapolis Star: Tick encounters across Indiana on the rise, climate change plays a role
