By Tessa Raebeck
As residents continue to report tick populations rising at alarming rates, communities across the East End are searching for sustainable methods of vector control.
Several publications, including Veterinary Practice News, predicted that tick populations would explode during the 2013 season. Speculated reasons for the influx include warmer winters, a rise in the white-tailed deer and wild turkey populations and increased suburbanization bringing people, wildlife (and ticks) closer together.
“This has been an incredible year for ticks,” said Sag Harbor resident Karen Lise Bjerring. “Never ever this many…I’ve had 27 bites so far.”
Due to the large population of white-tail deer, residents on the East End are at particular risk of contracting tick bites, which can result in a variety of illnesses.
According to the New York State Department of Health, “Since Lyme disease first became reportable in 1986, over 95,000 cases have now been confirmed in New York State.” Other tick-borne diseases “are most frequently found on Long Island and in the lower Hudson Valley region.”
According to experts with the Cornell Cooperative Extension of Suffolk County, it appears the increase in tick populations is not purely anecdotal. This includes the proliferation of the lone star tick — a species relatively new to the East End and garnering attention for its sheer numbers — and the alpha-gal allergy some residents have contracted after being bit by the lone star (see related story).
“I am sure if sampling for lone star tick had been done for the last 30 years, it would have clearly shown an increasing population here,” said Daniel Gilrein, an educator and entomologist for the Cornell Cooperative Extension. “That is partly because it is relatively ‘new’ to the area, expanding its range, and also seems to be highly correlated with our increasing deer population.”
According to Gilrein, a variety of tick species are also being affected by the increase in the deer population.
“It is clear to me that the increasing population of blacklegged (deer) tick — this is the species that can carry the pathogens causing Lyme disease, babesiosis or anaplasmosis — is also related to the high numbers of deer,” he said. “They both will utilize other hosts, but deer are really a key host for both ticks.”
An extensive study is being conducted by the extension’s Suffolk County branch on the effectiveness of 4-Poster devices on controlling regional tick populations. In 2007, 4-Poster devices were installed on Shelter Island and Fire Island, with a control study in North Haven.
The 4-Poster devices target the host directly, using corn bait to attract white-tailed deer to a feeding station. As deer feed, rollers treated with a pesticide called permethrin brush against the animal’s neck, head and ears.
“The 4-Poster technology was very effective for controlling our two main species of ticks, but it takes a couple of years to see results,” said Gilrein.
Shelter Island Town Supervisor James Dougherty agreed. “The 4-Poster program has been a big success on Shelter Island, in my view, in sharply reducing the tick population and incidence of tick-related diseases,” he said.
In 2009, after a year of using the devices, the “study sites had significantly lower tick abundances compared to the reference site,” according to a 2011 report by Gilrein, Paul Curtis, a wildlife specialist with the extension, and extension associate Susan Walker, the deer research coordinator of the 4-Poster program.
Despite the findings, the Shelter Island 4-Poster program was significantly cut in order to reduce costs.
“The all-in expense of maintaining a unit for a season is about $5,000,” said Dougherty.
“It is expensive mainly due to the rising price of corn bait (and given the deer population consuming it) and the need for frequent maintenance by a licensed professional for the duration of the ‘tick season,’” said Gilrein. The East End’s tick season runs 10 months, from March to early December.
According to Dougherty, Shelter Island deployed about 60 units annually during the program’s first three years.
“The past several years, because of cost constraints, we have only deployed about 20 4-Poster units per year,” he said. “This has been adequate for a year or two as a holding operation, but in my opinion, the tick population is on an upsurge on Shelter Island and we — government and private sources — must face up to the challenge and plan on deploying many more than 20 units in 2014.”
Due to concerns over the environmental impact and side effects of permethrin, the use of 4-Poster devices is currently illegal in all of New York State, except Suffolk County.
“A Department of Energy Conservation (DEC) permit is required (for baiting of deer) and the technology is not available to individual homeowners,” said Gilrein.
New York State restrictions do not allow 4-Poster devices within 300 feet of a “public highway, dwelling, multiple dwelling, playground or other place where children may be present without adult supervision.” Exceptions are permitted only if devices are fenced and have prior NYSDEC approval.
The results of the 4-Poster study will influence the state’s decision on tickicide registration and whether to permit use of the devices in the state.
The National Pesticide Information Center Technical Fact Sheet on permethrin outlines the toxicity on various types of animals.
Permethrin kills ticks because it “acts on the nervous system of insects. It interferes with sodium channels to disrupt the function of neurons, and causes muscles to spasm, culminating in paralysis and death.”
The pesticide is also “highly toxic to honeybees, fish, and aquatic invertebrates,” while “mammals are less susceptible to permethrin compared to insects.”
For humans, “Dermal exposure to permethrin may cause irritation, itching, or paresthesia (a tingly, prickly sensation) at the site of contact,” and, “ingestion of permethrin may cause sore throat, abdominal pain, nausea, and vomiting.”
The State of New York Department of Health Review of the 2008 Permethrin Residue Investigation Results found, “Results of sampling indicate that the health risks of handling and consuming venison or liver from deer known to have visited a 4-Poster device on Shelter Island is very low.”
“It continues to be used on Shelter Island where the results have been positive and Brookhaven Lab is now using it,” said Gilrein. “It can be an alternative to use of regular broadcast
sprays for ticks.”
Some residents of North Haven lobbied to get its board of trustees to consider implementing a 4-Poster program in that village. Village officials responded by suggesting North Haven could increase its cull in order to reduce the deer herd as a member of tick abatement. It also created an ad-hoc committee to research tick abatement strategies the village could implement. According to trustee Jeff Sander, who spearheaded that effort, the committee should be making its recommendations to the full village board next month.
Regardless of the potential harm or perceived benefits of 4-Poster devices, many continue to view the tick infestation as epidemic on Eastern Long Island. But there are several recommended methods to diminish the impact on your family.
The NYS Department of Health recommends avoiding the outdoors altogether. If this is not an option, the state advises that residents wear light-colored clothing, enclosed shoes, pants and long-sleeved shirts, check clothes and exposed skin frequently, consider using insect repellent, stay on well- traveled trails, avoid sitting directly on the ground, and keep long hair tied back.