How To Repel Ticks And Mosquitoes

Many people don’t know how to protect themselves from insect bites, despite the toll of Lyme, dengue, West Nile, and other infections. A 2016 survey found that almost a quarter of adults in the US could not identify even a single active ingredient in insect repellents. Even worse, 82% believed that some products were protective despite the evidence. Citronella was the most common chemical mistakenly thought to be effective. More people know they need to apply sunscreen compared to insect repellents.

It’s easy to take precautions and significantly reduce your risk of infection. Here’s how to protect yourself.

Learn about the insect’s behavior and habitat

Mosquitoes are attracted to us by chemicals produced as we sweat—lactic acid and 1-octen-3-ol—and carbon dioxide. More recent studies show that Aedes aegypti is also drawn to decanal and undecanal. These are chemicals in our sebum^⁠, an oily material secreted by our skin’s sebaceous glands. Another study found carboxylic acid in our skin to be an important attractant. These are important findings because they may lead to better insect repellents.

What time of day are they most active? Do they prefer inside or outside?

For example, Aedes aegypti, or Yellow fever mosquito, is most important in transmitting dengue, Chikungunya, and Zika. It lives in and around our houses and prefers to bite indoors. It’s most active at dawn and dusk.

Aedes albopictus, or the Asian tiger mosquito, is mostly an outdoor (garden) mosquito and likes brushy areas. It is more aggressive, usually biting in the early morning or late afternoon. It can also transmit dengue and Chikungunya.

Culex, or house mosquitoes, mainly spread viruses that cause West Nile fever and encephalitis, most often at dusk.

The Anopheles mosquito, which transmits malaria, bites more at night, making bed nets useful for prevention.

In terms of ticks, deer ticks are the biggest threat throughout the US. They like brushy areas, high grass, leaf litter, and a certain amount of humidity. So they are less likely to be a problem in lawns that are closely mowed. Staying in the middle of a mowed path will reduce your risk of exposure.

Insect repellents

The army developed DEET and it has been the “go-to” repellent. Despite concerns, it is considered safe and has not been shown to cause cancer or birth defects. At high concentrations, it can cause a rash. Children are more sensitive, and lower concentrations should be used for them. Also, do not apply DEET under clothing. Note that it will melt the plastic on cameras, binoculars, and some synthetic clothing.

Another excellent insect repellent is picaridin, from the plant that makes black pepper. It is effective against mosquitoes, biting flies, ticks, fleas, and chiggers. It, too, can cause skin irritation. Do not use it around fish.

IR3535 also has a broad spectrum of activity, working against mosquitoes, deer ticks, lice, and biting flies.

Oil of eucalyptus, or p-Menthane-3,8-diol, is a pesticide made from the lemon eucalyptus plant. It is effective against mosquitoes, biting flies, and gnats. Mosquitoes are repelled by the smell, as are some people.

One handy thing to look for is the EPA’s repellency symbol:

It shows whether a repellent is effective against ticks or mosquitoes and how long the product should work before it needs to be reapplied.

For protection from ticks, a must-have product, imho, is permethrin spray. I use Sawyer’s Premium Permethrin, with 0.5% permethrin, and spray shoes, a couple of sets of socks, pants, and shirts at the beginning of tick season. You need to remember to retreat your clothes after 6 washes or 6 weeks until the winter freeze comes, but it is very effective. Since I am bug bait, I also use picaridin or DEET on my exposed skin.

Some specific products that are highly recommended are:

Cutter Backwoods Dry aerosol^⁠, with 25% DEET, because it is sweat resistant and lasts 10 hours. It can be applied to either skin or clothing.

Cutter Backwoods Tick Defense contains 15% Picaridin. It also works against mosquitoes, lasts up to 10 hours, and can be used on either skin or clothing.

Sawyer Family Insect Repellent Controlled Release 20% Deet; compatible with sunscreen. Lasts up to 11 hours.

Sawyer Picaridin 20%^⁠, pump spray

Repel^⁠’s Oil of lemon eucalyptus 30%

Note that products with the same active ingredient sometimes have very different rankings, depending on how they are formulated. Deet at 25-30% have consistently high rankings. There is no need to use a higher concentration.

Despite public perceptions, citronella candles have almost no efficacy. The same is true of “natural” products like Cutter Natural, with geraniol oil, or Avon Skin So Soft. Nor are various wrist bands and ultrasonic devices effective.

Products like these are heavily marketed as an alternative to “chemicals,” although they are much less effective.

Best protections:

The most effective controls are limiting standing water, which is a breeding grounds for mosquitoes. Check your surroundings for standing water in gutters, bird baths, old tires, empty cans and lids, etc. Also, be sure to screen your windows. If you can’t afford that, consider a bed net.

Using permethrin on clothes and shoes will markedly reduce both your tick and mosquito exposure. For ticks, showering when you return from a hike or working outdoors and doing a full body check for the little critters will greatly reduce your risk. You can often feel tiny ticks before they are easily visible.

For women gardeners in cooler climates, wearing pantyhose will keep ticks from attaching to your lower body / legs.

With climate change, the range of ticks and mosquito-borne infections is greatly expanding. It’s important to be more cautious to protect yourself and your family.