Any time there is standing water around, mosquitos may be breeding in your yard. But warm, humid weather accelerates the breeding cycle—which means this year’s mosquito season is about to get underway.
And with all of the recent news about the mosquito-borne Zika virus outbreak, it’s especially important to take precautions to keep from being bitten by these potentially deadly insects.
There are a whopping 2,700 species of mosquitos worldwide. Not all species bite humans, but most have a genetic predisposition to find you—whether by sight, smell, body heat, or interpreting your chemical signals.
But the good news is there are some simple precautions you can take to minimize your chances of getting bitten—and contracting viruses and diseases spread by mosquitos.
I’ll tell you about these precautions in a moment. But first, let’s look more closely at the types of illnesses mosquitoes can transmit, and how they do it.
The mosquito-borne illness you need to worry most about
Mosquitos carry deadly, infectious diseases like malaria, dengue fever, and West Nile virus. They also transmit yellow fever, but the last case in the U.S. was way back in 1906, at Charity Hospital in Louisiana.
Most recently, concerns have focused on the mosquito-borne Zika virus. As I wrote in a trio of Daily Dispatches in March and April, Zika had been around the South Pacific for decades, but has suddenly exploded onto the scene in Brazil.
While about 80 percent of people infected with Zika have no symptoms, the virus is dangerous for pregnant women. In Brazil, there’s a growing epidemic of infants with abnormally small heads (microcephaly) born to women infected with the Zika virus.
And Zika may be on its way to North America—in fact, the mosquito that carries it already lives in the southeastern U.S. and has been discovered as far north as Washington D.C. (where mosquito-borne malaria thrived until the 20th century).
But at this point, Zika is not the mosquito-borne illness you really need to watch out for (unless you’re pregnant).
The West Nile virus has caused much more harm in the U.S. than Zika. West Nile first appeared here in 1999, accompanied by much hysteria. As of 2014, the CDC notes that more than 40,000 people have been infected. Nearly half of those people became seriously ill, and 1,765 died.1
Of course, that’s just the reported cases. The number of people infected with the West Nile virus is likely many, many times higher. The CDC notes that most West Nile cases are not reported because 70 to 80 percent of people infected with the virus don’t show symptoms. But if you have been bitten by mosquitos and have a headache, body aches, joint pains, vomiting, diarrhea, or a rash, that might indicate you have West Nile.
It’s a good idea to check in with your doctor if you experience any of the above symptoms this summer. Especially if you’re over age 60, or have high blood pressure, diabetes, cancer, or kidney disease. The CDC reports that people in these categories are more prone to having severe, potentially life-threatening West Nile infections. Treatment in those cases usually entails hospitalization, intravenous fluids, and pain medication.
Why mosquitos are so deadly
As I noted earlier, mosquitos breed in stagnant water. And it doesn’t have to be a pond or even a puddle. In as short as a week, thousands of mosquitos can emerge from just a small amount of water—like what you might find left sitting in a bucket, old tire, or watering can.
Females lay 100 to 400 eggs on a “raft,” which floats on top of the water. According to the EPA, a mosquito can live anywhere from four days to a month. And some mosquito species can lay up to 1,000 eggs in a lifetime.
The larvae hatch and breathe through tubes while remaining under water. They then go through a pupae stage, and once they’re adults, feeding (including biting) and mating begins.
Like all insects, or arthropods, mosquitos have a body divided into three parts: head, thorax, and abdomen, with a hard exoskeleton (or shell); six, long jointed legs; and two veined wings. The body is small enough that they have an open circulatory system, whereby air flows through the body chambers and directly delivers oxygen for energy metabolism.
Mosquitos don’t technically have a stinger. Instead, they have a nose, or proboscis, that draws fluids—they can’t eat solids.
Interestingly, only the females bite, because they need what’s known as a “blood meal” to help develop their eggs. Males drink only plant nectar.
And while humans are a common target, female mosquitos often prefer to feed on birds. The house sparrow and house finch are two species known to have high rates of infection with the encephalitis virus carried by mosquitos.
When a female finds an unsuspecting human or bird, she pushes a needle-like stylus through the skin and into a superficial blood vessel to feed. Her saliva contains an anticoagulant called hirudine (like the pharmaceutical anticoagulant heparin) to prevent blood clotting.
Since hirudine is a foreign protein for humans, the body mounts an immune reaction that causes the typical swelling, redness, and itchiness after being bit.
A mosquito can suck up almost twice her weight in blood, swelling her abdomen. She leaves behind a droplet excreted from her intestines to reduce her weight, so she can take off and fly away again.
Six simple ways you can lower your risk of mosquito bites
As I said earlier, mosquitos have many ways of finding you. Not only can they see and smell you, but they can also detect the higher body heat of warm-blooded animals, like humans.
Mosquitos also detect chemicals such as carbon dioxide, which you breathe out, and lactic acid, which can build up in your muscles.
And it has also been noted that people who sweat less don’t get bit as much. (Maybe that’s why Marco Rubio wanted to leave Florida for the White House; although he would just have been trading one swamp for another.)
Of course, there’s nothing you can do about these types of physiological attractions for mosquitos. But there are other precautions you can take. Here are six proven ways to help lower your risk of mosquito bites.
1) Check your color palette. Dark colors provide visual signals to mosquitos. So wear light-colored clothes (a good and fashionable idea in late spring and summer anyway). If weather permits, limit your skin exposure by wearing long sleeves, long pants or dresses, and socks.
2) Stay still. Mosquitos are attracted to movement. Of course, I always encourage you to get healthy physical activity outdoors. So if you’re out walking or biking or playing games in the backyard, make sure to follow step No. 4…
3) Spray clothes and exposed skin with natural mosquito repellents. DEET confuses mosquitos’ chemical sensors. But it is a known toxin that’s absorbed directly into the skin. Studies show that a synthetic product called picaridin, which is found in brands like Cutter and Avon, is as effective as DEET and potentially safer. Picaridin was developed in the 1980s and was made to resemble the natural compound piperine (black pepper extract). You can also use citronella (from lemon and citrus fruit), eucalyptus, or tea tree oils as natural repellents.
Many repellents that are designed to be sprayed on clothes contain a chemical called permethrin. Make sure not to spray it directly onto your skin, as it may cause irritation.
4) Let the sun (or moon) shine. Mosquitos are most active during dawn and dusk, so avoid being outdoors at those times. Like mad dogs and Englishmen, go out in the noon-day sun. Or after dark.
5) Screen out insects. Keep window and door screens in good condition and tightly fitting.
6) And, of course, eliminate standing water in clogged gutters, wheelbarrows, buckets, watering cans, rain barrels, and stagnant bird baths.
DDT’s widespread damage continues, 40 years after being banned
Protect yourself with a single, simple supplement
Communities used to spray the deadly toxin DDT to eliminate mosquitos. Although DDT has been banned in the U.S. and many other countries, residues can remain in the environment, and in the body, for many years.
If you were ever exposed to DDT, recent research shows that B vitamins protect against the lingering health effects of this chemical.
High levels of DDT in the body can increase the risk of early miscarriage and interfere with the ability of women to conceive. But a study of 291 women found that taking B vitamins can actually reverse these negative effects.2
Researchers measured DDT, vitamin B6 and B12, and folate levels in the study participants. They found that the women with higher DDT levels and lower vitamin B levels took nearly twice as long to become pregnant, and suffered double the rate of early-term miscarriages.
But women with sufficient vitamin B12 were not impacted by DDT at all. And those with high DDT levels who took extra folate were less likely to miscarry.
The researchers said improved nutrition helps the body cope better with environmental toxins and stressors like DDT. Of course, this was one of the original purposes of vitamins in nature.
Protecting yourself from the ongoing havoc wreaked by DDT is just one more reason to get adequate B vitamins. You can help ensure that by taking a high-quality B supplement every day.
2“Preconception serum 1,1,1-trichloro-2,2,bis(p-chlorophenyl)ethane and B-vitamin status: independent and joint effects on women’s reproductive outcomes.” American Journal of Clinical Nutrition, 2014; 100 (6): 1470.