The Science of Mosquito Repellents: How to Protect Yourself This Summer

Friday - July 21 2023, 05:08 UTC - 1 year ago

In the summer, mosquitoes come out across the US, and the use of mosquito repellents can protect your health and sanity. These repellents interfere with a mosquito's sense of smell, taste or both, although not all work. To stay safe, always read the labels of any products you use and avoid bracelets and ultrasonic repellent devices.

Now that summer is in full swing, mosquitoes have come out across the United States. The use of mosquito repellents can protect both your health and sanity this summer.

While mosquitoes leave bothersome, itchy bites on your skin, they can also pose a serious and sometimes deadly risk to your health. When a mosquito bites you, it may transmit harmful pathogens that cause dangerous diseases like malaria, dengue fever, Zika and West Nile.

Avoiding mosquito bites .

Mosquito females bite people to get vital nutrients from our blood. They then use these nutrients to make their eggs. One single blood meal can give rise to about 100 mosquito eggs that hatch into wiggling larvae.

There are several ways to avoid getting bitten by mosquitoes, from wearing long, loose clothing and limiting time outside to placing screens over your windows and getting rid of standing water that mosquitoes might use to breed.

However, one of the best ways to protect yourself when you’re going to a place where hungry mosquitoes will be buzzing around is by using mosquito repellents.

Our team at the New Mexico State University Molecular Vector Physiology Laboratory has studied different types of mosquito repellents and their efficacy for over a decade. Here’s what you need to know to protect yourself this summer: .

All about repellents .

The use of mosquito repellents goes far back in history, certainly predating written historical accounts. Some of the oldest records of the use of mosquito repellents date back to early Egyptian and Roman history. During this period, smoke from smudge fires was often used to repel mosquitoes.

Today, we have more options than our ancestors when it comes to choosing what type of mosquito repellent to use – sprays and lotions, candles, coils and vaporizers, to name some.

These repellents interfere with a mosquito’s sense of smell, taste or both. The repellent either blocks or overstimulates these senses. Scientists understand how certain repellents like DEET work at the molecular level, but for many of them, it is still unknown why exactly they repel mosquitoes.

Testing repellents .

We used a variety of scientific laboratory experiments and field tests to find out what works. For some products, testing was as simple as putting a volunteer’s treated arm into a cage with 25 mosquitoes and waiting for the first mosquito bite.

For others, like citronella candles, we used a slow-speed wind tunnel and put a candle or device between a person and a cage of mosquitoes. Depending on the repellent efficacy of the device, mosquitoes either flew toward the person or away. Another experiment we conducted was the Y-tube choice assay where mosquitoes chose to fly toward someone’s hand or, if repelled, fly toward the blank or empty option.

Mosquito repellents that don’t work .

Bracelets don’t work. Department stores and pharmacy chains sell hundreds of different varieties of bracelets. They are marketed as "mosquito repellent" bands, wristbands and watches, and their materials can vary from plastic to leather. Even if they are loaded with repellents, they can’t protect your whole body from mosquito bites.

Ultrasonic repellent devices are also not effective. Industry studies have found that they don’t repel mosquitoes in any meaningful or consistent way.

Takeaways .

Today, you can choose from a variety of mosquito repellents, ranging from sprays and lotions to candles and coils. Some work better than others in terms of repelling mosquitoes, but it’s good to note that none are 100% effective in every situation.

It’s also important to always read the label of any product you use. Some repellents should be used differently depending on your age and any medical conditions you may have.