Mosquito Repellents: What Works

From zappers to catchers to candles to sprays, mosquito repellents come in many forms. But which ones work? We’ll tell you.

Mosquitos don’t just whine in your ear and drive you mad with itching, but they also spread disease to more than 700 million people every year. Here’s how to stay off a mosquito’s menu.

Who’s For Lunch?

Do you seem to get eaten alive when others are left alone? You’re probably not just imagining it.

Mosquitoes are attracted to carbon dioxide as well as the warmth and humidity you’re giving off, says Renee Anderson, PhD, a medical entomologist at Cornell University in Ithaca, N.Y. They follow the trail, flying in a zigzag pattern, until they find the source. In addition, they are also attracted to certain chemicals in your sweat. And mosquitoes love a moving target — it helps them zero in.

How to Stay Off the Menu

In general, mosquito repellent works by masking the chemical cues that welcome mosquitoes to dine.

How to Choose Mosquito Repellent

Insect repellents work by making us unattractive to biting bugs like mosquitos, ticks, and flies: just apply the repellent and they should avoid the treated area. Mosquito repellents in particular do this in a number of ways, using either synthetic or natural chemicals. How can you choose the best product, though? It depends. Think not only about what active ingredient you want in a mosquito repellent, but also about how long and where you need to be protected.

Choosing by Active Ingredient

Consider a DEET-based product. DEET stands for either N,N-diethyl-m-toluamide or N,N-diemethylbenzamideis. It is a reliable mosquito repellent that has been in use in the US since the late 1950s under brands like Cutter, Repeller, and Off! You can find DEET mosquito repellents at most outdoors, sporting goods, and hardware stores in lotion and spray forms

Try a Picaridin alternative to DEET. Picaridin was created by Bayer corporation in the 1980s as an alternative active ingredient to DEET and has been available in repellents in the US since 2005. It’s as effective in keeping away mosquitos but lacks some of DEET’s unpleasant qualities. Consider it if you’re wary of DEET

Think about a Permethrin repellent. Permethrin is another proven repellent. It has been used in agriculture, for lice in humans and animals, and as a repellent for mosquitos, ticks, and other insects. It can also last a long time. The thing that makes this product stand out, however, is that it’s used on clothes rather than on skin

Consider other plant-based repellents. There are a number of mosquito repellents with other kinds of active ingredients, many derived from plants. You might want to consider these products if you are concerned about the possible side effects and toxicity of chemicals like DEET or Permethrin

How to choose a good mosquito net

Malaria is transmitted by the female Anopheles mosquito that bites humans from dusk to dawn. The Anopheles mosquito is stealthy and silent. They don’t buzz so you can’t hear them approaching. This means you are a prime target when you are most vulnerable — asleep.

Bed nets are a key defence against malaria, but they also offer protection from other diseases such as filariasis (known for massive swelling of the limbs) and other insects and arachnids like ticks, beetles, flies, and spiders. Remember that in malarious areas, bedrooms without tightly-fitting screens or broken screens require insecticide-treated mosquito bed nets, except in buildings with sealed windows and central air conditioning.

Features to look for in a well-designed bed net

• Choose a tightly woven, white net big enough to tuck under your mattress. The netting should be made of stiff cotton or synthetic thread to allow the movement of air. A white net allows you to see mosquitoes against the background. Netting with 285 holes per square inch will prevent even the smallest mosquito from squeezing through. (You can find out the number of holes per square inch by multiplying the number of holes along the length of a square inch of net and the number of holes along the height.)

• Different bed net styles provide different levels of protection. Rectangular bed nets are a great option because they reduce your chance of touching the net while you sleep. You are more likely to touch the netting when sleeping under a cone-shaped net, which could allow insects to bite through.

• Insecticide-treated nets are more effective than untreated nets. Nets treated with an insecticide like permethrin kill insects on contact. Some bed nets come pre-treated or you can treat them yourself by soaking your bed net in a permethrin solution, available in many travel health clinics and outdoor equipment stores. (Note that permethrin treatment products are not sold in Canada.)

HOW DO MOSQUITOS CHOOSE THEIR VICTIMS?

Mosquitoes do not choose their victims because of the sweetness of their skin. They do it based on various factors. First, depending on the amount of carbon dioxide (CO2) emitted by the person breathing. A human being produces every day about one CO2 kg. Mosquitoes detect a pulse current inviting them to suck that fresh blood. So, to be a good victim you must meet the requirement to be a good CO2 emitter.

Another of the reasons why mosquitoes are attracted to choose their victims is the lactic acid we emit while breathing or through sweat. Taller people and pregnant emit more CO2and lactic acid, which are perfect targets for mosquitoes, like people who exercise outdoors. Mosquitoes have 27 odorant receptors and lactic acid to detect the sweat that activates their radars. This substance, together with carbon dioxide, is an indicator that we are mammals and, therefore, we can provide blood.

Genetics also play an important role in the decision. As explained Diego Hoyos, pharmacist, the blood group 0 is their favorite.

So, in fact, we can do nothing to prevent being elected. While we can avoid doing activities and sweating outdoors in areas where there are many mosquitoes, the best choice is to protect us wherever we go with a device that is both comfortable and effective.

To protect your home, it is best to bet on the most specialized technologies and focus on what’s practical and hygienic, free from chemicals and toxic products.

Tips for Choosing the Best Bug Spray

As the weather warms up and you head outdoors, remember, humans are not the only species to delight in such balmy days: Summer is also a busy season for pesky insects that can bite or sting you, or even transmit a disease.

Fortunately, you can take steps to protect yourself from being bitten up by eager mosquitoes, ticks or flies.

The Centers for Disease Control and Prevention recommends that you use products containing one of three active ingredients — synthetic chemicals, such as DEET; picaridin; or plant-derived chemicals, such as oil of lemon eucalyptus — provide the longest-lasting protection. (The chemical names for DEET may be listed on the product label as the ingredients N,N-diethyl-m-toluamide or N,N-diemethylbenzamide.) Read product labels carefully, because not everyone should use every product: They may say that oil of lemon eucalyptus should not be used on children under age 3 or that products containing DEET should not be used on infants under 2 months of age.

Look for a product that offers at least 60 minutes of complete protection with the first application, Day said. DEET products, even those containing the lowest concentrations of DEET (5 to 7 percent), provide about 90 minutes of complete protection when first put on. Your level of activity also affects how long the protection will last. If you are lying in a hammock, you might get that entire hour and a half of complete protection from a low-concentration DEET product. That same product won’t last as long if you’re playing softball, running or engaging in some other sweaty activity, he said

Most repellents have chemicals in them that can be irritating to the skin as well as to areas close to the eyes, ears, nose and mouth. To keep irritation to a minimum, Day suggests using a lower-concentration DEET product or some other product. Also, when you’re applying bug spray to your face, first place the repellent on your hands, and then use your hands to put it on your face, Day said.