When to Hire a Pesticide Professional
While the risk of tick bites can be reduced by personal protection, landscape management and property owner-applied pesticides, if the risk of exposure of in your area is high, consider hiring a licensed commercial applicator. A professional can apply effective, EPA-registered acaricides – pesticides that kill ticks – with specialized equipment to reach ticks secluded within the leaf litter.
- Bifenthrin is a synthetic pyrethroid that is commonly used to control deer ticks. It is extremely effective on ticks and retains residual activity for 1-3 months. Although lethal to fish and aquatic invertebrates, it binds tightly to soil, therefore its runoff is limited. It is also less expensive per square foot covered than currently available botanical acaricides.
- One previously marketed, non-synthetic botanical mixture (IC2) containing 10% rosemary oil has been shown to be almost as effective as bifenthrin when applied by a high-pressure hose. This minimal-risk, food-grade product is stated to be safe for use near wetlands and open water, thus it may represent an effective, though more costly, substitute for synthetics where environmental harm is an important concern. Registration for an identical product is pending in Maine. As development of other non-synthetics is increasing, Independent validation of their effectiveness will be needed.
Applicator-applied Host-targeted Acaricides
Bait Box. Target: Mice
The goal of this approach is to kill ticks feeding on mice, the predominant hosts for juvenile deer ticks and principal carriers of Lyme disease and anaplasmosis.
- Bait draws the mice into a tamper-proof, child-resistant box where they come in contact with wicks treated with fipronil, an EPA-registered pesticide that is effective against ticks. (Fipronil is the active ingredient in the popular flea and tick treatment veterinarians commonly prescribe for household pets.)
- Mice enter the boxes through a small opening, then move through the box, passing under a small wick. The wick lightly brushes the mouse, gently applying a very small amount of low-dose fipronil. The fipronil won't harm the mouse or any other animal that might touch or eat it, but it will kill the ticks on the mouse.
- Since the only acaricide to escape the box is the tiny amount brushed onto the mouse, the environmental impact of this treatment is nil.
- Bait boxes are typically placed 30 to 50 feet apart in the spring and the fall, coinciding with the peak seasons for deer tick nymphs and larvae, respectively.
- Studies have shown 60- 80% reduction in ticks after one year, 90-100% after two years. Simultaneously, the percentage of ticks that were infected dropped from 25% to 2%.
This device attracts white-tailed deer to feed on corn from a central bin. As the deer reach for the corn, their ears, heads, necks, and shoulders rub against vertical rollers that are treated with acaricide. Through grooming, the deer also transfer the acaricide to other parts of their bodies.
Typically about 52 of these devices are set per 2 square miles, which is why they are better suited to communities than to individual properties.
Several studies have demonstrated significant reductions in deer tick nymphs following the use of 4-posters in spring and fall over a 4-5 year period.
Some cautionary notes:
- Their application requires trained licensed applicators to tend each device weekly to apply acaricide and sometimes twice-weekly to replenish the bins with washed, whole-kernel corn.
- Each unit with acaricide costs about $780, with corn and labor additional. Labor costs can be high due to the need to tend each device frequently and the large area covered.
- In one study, fall consumption for approximately 22 4-posters ranged from 796 to 10,560 pounds of corn, a significant expense.
- In years when alternative natural food is abundant, deer's use of the devices will decrease.
- Several states ban 4-Posters, concerned that gathered deer will promote the spread of infectious diseases. Check with the Maine Department of Inland Fisheries and Wildlife.