Silver-spotted Skipper (Epargyreus clarus). In a soon-to-be-published VCE study, tick spraying was associated with a five to 30% immediate decline for most invertebrate groups, especially less mobile and soft-bodied arthropods, like native caterpillars that turn into moths and butterflies. Photo credit iNaturalist user @gbyoung04
Growing up in New York City, ticks rarely registered as a concern of mine. Now, as someone who lives in Vermont full-time and is pursuing a degree in ecology, I can’t help but worry about ticks every morning as I tuck my long pants into my socks before heading out into the field.
Last year, I was talking to my mom at the dinner table about my future career goals, and she suggested that I switch to a science with fewer ticks… like chemistry.
Beyond questionable fashion decisions and offhand jokes,“tick anxiety” is a widespread reality for many Vermonters, and not without good reason. As of 2022, the CDC reported that Vermont had the second highest rate of Lyme Disease per population in the country, second only to Rhode Island. Moreover, 1988 marks the first year lyme disease was found within Vermont, making tick-borne diseases a relatively new public health concern for the state. With limited research and new threats cropping up yearly, it’s no surprise that our collective panic continues to churn out misinformation.
Curious about common tick misconceptions, I had a lengthy discussion with Juno Stahl, a former intern and now a seasonal biologist for Vermont Center for Ecostudies at the beginning of the summer. They worked closely under the Backyard Tick Project last year with VCE biologist Jason Hill, and their time collecting and observing backyard ticks around the state has given them unique insights into where they’re found and how they behave.
Juno brought up two prime examples of how tick anxiety may be harming pollinator conservation across the state: mowing and pesticides.
Mowing and Ticks
Widespread mowing is a prime example of how our collective fear of ticks is continuing to inform harmful land management practices. Grass lawns are almost complete monocultures, meaning they primarily consist of a singular species. The mowing of residential properties can create pockets of ecological desert that typically reduce insect biodiversity. One urban trial found that wildflower meadows support nearly four times more insect species than adjacent lawns.
The widespread decline in beneficial insects has prompted movements to reduce mowing on lawns across the country, most notably the creation of “No-Mow May.” However, the resistance to anti-mowing movements often goes beyond the desire for an aesthetically manicured lawn— many people fear that it may increase the number of ticks in their backyard.
“I think a lot of people assume immediately that if they see tall grass they are going to find ticks,” Juno says. “But that is not necessarily the case. Ticks actually prefer low woody shrubby areas over grasslands. You can find them crawling around on the edge of lawns that are even freshly mowed, so grass height doesn’t necessarily correlate with whether ticks will exist in that area.”
Instead of grass height, environmental microclimates are a much more reliable indicator of tick presence. Ticks have a hard time tolerating dry environments, so they are most likely to be found in moist, shady areas where they are able to retain moisture; for example, shrubby understories or leaf litter.
Tick Spraying and Pollinators
Along with keeping grass short, the expanding prevalence of ticks in Vermont has triggered the widespread residential use of pesticides for tick control. For many, feeling proactive about preventing tick borne illnesses outweighs exorbitant maintenance costs, or even the actual effectiveness of the treatment.
Spearheaded by VCE biologist Jason Hill, VCE’s Backyard Tick Project has been running for the past two summers to examine whether pesticide use in residential areas successfully reduces tick populations, and if it impacts beneficial insects and pollinators.
The first finding was that many homeowners may not need to manage for ticks. Across the approximately 200 properties surveyed across Vermont and New Hampshire, the study documented low tick densities in lawns, averaging around two ticks per yard.
The next finding was that tick spraying may not achieve what we’re hoping for. “Depending on the pesticide being used, spraying reduced tick density by around 60%,” Jason says. Although an immediate 60% reduction in ticks might seem worth it, long term tick density remains unaffected by treatment. “In a matter of a few weeks, the tick density likely goes right back to pre-spraying levels,” he says, “with ticks moving in from non-treated areas.” The Backyard Tick Project found no relationship between tick density within a lawn and that property’s history of pesticide use. “We had some properties that had been sprayed more than 80 times over the last decade, and they had the same tick densities in the lawn as a property that was just sprayed a week ago for the first time. There’s just no evidence that spraying is a long-term solution for tick control, or that it reduces one’s risk of tick-borne illnesses,” says Jason.
A far bigger concern may be the collateral damage these pesticides have on native pollinators and other invertebrates. “Alarmingly, pesticide spraying was associated with a five to 30% immediate decline for most invertebrate groups within and along the edge of the sprayed lawns. Less mobile and soft-bodied arthropods, including caterpillars were the most directly affected,” says Jason.
Even natural or “environmentally friendly” pesticide alternatives, such as essential oil-based pesticides, have negative effects on pollinators. Residential tick control companies often claim that the essential oil-based pesticides they use are pollinator friendly, but these claims are likely not based on real data. “There’s nothing magical in the chemistry of these pesticides that allow them to only kill ticks,” says Jason. “Many companies use the same essential oil-based pesticide to treat ticks, mosquitoes, and ‘stinging, biting and boring’ insects. It’s a safe bet that if a product kills ticks, then it also likely kills pollinators and other invertebrates as well.”
So if spraying and mowing your lawn isn’t a long-term solution to keeping you safe from ticks, then what is? Jason suggests four preventive measures.
- Wear long pants tucked into your socks and long-sleeved shirts tucked into your pants when in areas where there may be ticks, and check your clothing and your exposed body parts for ticks frequently.
- Apply a Picaridin-based tick repellant every few hours to your shoes and clothing. “Tick repellents are effective for only short periods of time,” says Jason, “and must be reapplied to be effective.”
- When you come in from outside, undress and immediately do the laundry. Don’t put your clothing in the hamper. “I can’t tell you how many times I’ve gotten into bed and observed a tick crawling up the wall from our bedroom laundry basket,” Jason says. Don’t line dry, either. While hot water will not kill ticks, five minutes on high in the dryer will. If you have dirt or stains on your clothes, you can wash them first, but switch them directly to the dryer right after.
- Make thorough full-body tick checks a part of your night time routine, like brushing and flossing your teeth. A thorough tick check means checking everywhere, especially the warm dark areas where they like to hide. If you do find a tick, remove it promptly by following these recommendations from the Center for Disease Control.
- If you have outdoor pets that come into your house, regardless of whether they wear tick collars or take tick medicine, check them and their bedding areas for ticks every day. “Studies consistently find that pet owners have elevated risks of encountering ticks inside their house and being diagnosed with a tick-borne disease,” says Jason.
For many Vermonters, the fear of tick borne disease is deeply personal. Many start looking for ways to reduce ticks after they or a loved one contracted Lyme disease or another tick-borne illness. However, in our efforts to keep our world safe, we can jeopardize the very things that keep it alive. I’m not proposing we stop looking for ways to reduce tick populations, we absolutely should. But perhaps we should examine how a search for solutions can safely coexist with a deeper understanding of our ecological landscape.
