Although you might find them annoying in the summertime, mosquitoes are an important part of the ecosystem. Mosquito larvae live in the water and provide food for fish and other wildlife, including larvae of other species such as dragonflies. Mosquito larvae eat and recycle microscopic organic matter.
Adult mosquitoes are part of the diet of insect-eating animals such as bats, spiders, and dragonflies. They also help pollinate flowers as they drink the nectar. Opinions differ as to what would happen if mosquitoes were eradicated from the face of the Earth.1
Some estimate the number of migratory birds nesting between Canada and Russia would drop by more than 50 percent. In the absence of larvae, hundreds of species of fish would need to change their diet to survive. Most mosquito-eating birds would need to switch to other insects. Overall, mosquito loss would be experienced by many species.
That said, for humans, they are an annoyance. While male mosquitoes don't bite humans, but rather feed off flowers’ nectar, females require proteins and other components in blood meals to develop and lay eggs.
At best, the bite is an itchy nuisance and at worse it may transmit diseases like malaria, encephalitis and West Nile virus. Mosquitoes may even spread Lyme disease. A recent study by researchers in Malaysia suggests mosquitoes were affected by electronic music.2
Electronic Music May Help Reduce Mosquito Bites
Recognizing mosquitoes use sound to communicate, and that communication is crucial for survival and population maintenance, researchers from the University of Malaysia decided to investigate whether mosquito behavior could be disrupted by playing a track from dubstep artists Shrillex.3
The experiment was designed to compare feeding and mating behavior in the presence of a specific track, “Scary Monsters and Nice Sprites,” as compared to mosquitoes not exposed to music.
The music track peaked at 77 on the music charts in the U.K. in 2010 and won the best dance recording at the 54th Grammy Awards in the U.S.4 The soundtrack was chosen because it has a wide range of high and low frequencies. The researchers commented on their choice of music, saying,5
“In insects, low-frequency vibrations facilitate sexual interactions, whereas noise disrupts the perception of signals from conspecifics [members of the same species] and hosts.”
The researchers described the female adult mosquitoes behavior as “entertained” and found they attacked their host later and less often than those who were in a music-free environment. They also found mosquitoes exposed to the song bred far less often. The researchers concluded:6
“The observation that such music can delay host attack, reduce blood feeding, and disrupt mating provides new avenues for the development of music-based personal protective and control measures against Aedes-borne diseases.”
What Attracts Mosquitoes?
If playing loud electronic music in your backyard is not how you’d like to deter mosquito bites, you may want to start by learning what attracts them in the first place. Of the 3,000 different species in the world, only roughly 175 are found in the U.S.7 Each species differs in its persistence, biting habits and ability to transmit disease.
Nearly all are attracted by a number of chemical compounds, including the odor of carbon dioxide you produce every time you exhale. High concentrations of carbon dioxide may be detected from more than 150 feet away.8 Other odors released in perspiration are also likely to attract mosquitoes, such as lactic acid and ammonia released by bacteria living on the human skin.9
The higher your body temperature, the more likely you are to sweat, which is why mosquitoes frequently bite around feet, ankles, wrists, and hands. These are all areas that tend to retain moisture and have larger bacterial colonies. If you're warmer than the person next to you, mosquitoes will target you.
Women in the latter stages of pregnancy, people who are overweight and joggers also tend to be bitten more. One study from Japan10 demonstrated those with type O blood may be more likely to be bitten than those with type A. Mosquitoes are also attracted to alcohol.11
The female has a mouth part called a proboscis, which is much like a hypodermic needle.12 She uses it to pierce your skin until she finds a capillary from which to suck blood. At the same time, she injects some of her own salivae to stop the blood from coagulating. It is at this point she may transmit the disease directly into your bloodstream. The chemicals in her saliva trigger the reaction on your skin.13
Some Get Bitten More Than Others
Mosquitoes target their prey based on chemical scent. Lactic acid, commonly found in human sweat, is known to consistently attract more mosquitoes. When lactic acid was added to animal odor samples, mosquitoes responded as they did to human odors.
In one study,14 data demonstrated the scent-based preferences of the anthropophilic mosquito A. aegypti, known to carry yellow fever. The preferences were due to the differences in the amount of lactic acid found on the host.
Researchers have found mosquito species exist specializing in biting humans, including those carrying malaria and yellow fever. They have evolved a remarkable innate preference for human scent.15
Researchers have also isolated compounds naturally occurring on the human skin, such as 1-methylpiperazine, which blocks the mosquitoes’ sense of smell and essentially makes it so the insects are oblivious to the presence of a host. The substance is produced by bacteria on your skin. Researchers are hoping to be able to make it on a large scale to replace dangerous chemical repellents.16
Some people are capable of secreting more of these natural substances than others, making them virtually invisible to mosquitoes. While researchers work on figuring out how to keep 1-methylpiperazine from evaporating off the skin naturally over time, it's crucial you steer clear of mosquito repellent containing N, N-diethyl-meta-toluamide, commonly known as DEET.17
Steer Clear of DEET
Most conventional insect repellents contain DEET, chemical mosquitoes find unpleasant. The compound is a colorless, oily liquid developed by the U.S. Army to protect soldiers in jungle warfare. After a request from the National Park Service, employees of the Everglades National Park, Florida, were investigated for adverse health effects from exposure to DEET.18
Anecdotal reports of confusion, abnormal sweating and neurobehavioral symptoms triggered the evaluation. A self-administered questionnaire was given to 143 employees and a urinalysis done in 20. Researchers found correlations between DEET use and affective symptoms, insomnia, muscle cramps, and urinary hesitation.
Seventy-seven workers participated in a follow-up survey and researchers found impaired cognitive functioning and daytime sleepiness increased after exposure. They concluded the skin rashes, impaired cognitive function, and daytime sleepiness was associated with exposure to the insect repellent.19
Children experience greater risk for subtle changes as their skin more readily absorbs chemicals, and the chemicals exert a more powerful effect on their developing nervous system.
Another potentially harmful chemical found in many bug sprays is permethrin. This chemical is a member of the synthetic pyrethroid family, known to be neurotoxic. The U.S. Environmental Protection Agency has also listed permethrin as carcinogenic.20 Pyrethroids have recently been linked to behavior problems in children as well.
Permethrin is toxic to the environment, especially to bees and aquatic life, and is extremely toxic to cats.21 Even a few drops may be lethal to your feline friend. It is used in some topical flea products, so when you see “for dogs only” on the label, it likely contains permethrin. For more information, please refer to the Environmental Working Group's extensive review of bug repellent ingredients.22
Reduce Mosquito Populations on Your Property and Treat Bites at Home
There are a few natural methods of preventing mosquito bites. One of the best ways is by avoiding them in the first place and staying inside between dusk and dawn when they are most active. Mosquito populations are also thicker near shrubs and standing water.
According to the American Mosquito Control Association, an efficient way to control mosquito populations is to eliminate their larval habitat.23 Mosquitoes use wetlands such as swamps or sluggishly moving streams and ditches to lay their eggs. Homeowners may look for areas in their yard where mosquito breeding may take place, such as any place water may be left standing.
For water, you would like to keep outside, such as water for your pets or a birdbath, be sure to change it at least every two days. Keep your rain gutters clean and flowing well and fill in or drain any puddles in the yard. Another area mosquitoes will lay their eggs is in trapped water inside plastic or canvas tarps used to cover your boat or pool.
Dress in lightly colored, loose-fitting clothing with long sleeves and long pants to reduce the number of bites. Bat houses are becoming increasingly popular since they voraciously eat mosquitoes and other insects. For more on buying a bat house or constructing one yourself, visit the Organization for Bat Conservation.24
Once bitten, your objective will change from repelling to treating the itch and inflammation. Fortunately, there are a number of natural herbs and agents with anti-inflammatory and antimicrobial properties to help soothe your skin. For a list of those see my previous article, “What Attracts Mosquitoes and How to Repel Them.”
Use Natural Methods to Repel Mosquitoes
Vector-borne illnesses, or those transmitted to their host by other creatures serving to harbor pathogens, are preventable using natural repellents to prevent transmission.
Vector-borne illnesses may be transmitted by insect bites. A study,25 led by entomologist Jerry Zhu from USDA’s Agricultural Research Service found compounds in coconut oil strongly repelled mosquitoes and ticks.26
The compound used was not pure coconut oil, but rather a fatty acid mixture of lauric acid, caprylic acid, and capric acid. After encapsulating these acids in a starch-based formula, the researchers demonstrated the formulation could protect cattle against biting flies for up to four days.
By comparison, DEET was only 50% effective against biting flies while the coconut oil compound was more than 95% effective. When tested on human participants, researchers found 90% repellency and longer lasting protection than other known natural repellents.
DEET is not your only option for insect repellent as tests have revealed natural alternatives that could be more effective without the harsh side effects. For a discussion of your options, see my previous article, “This Natural Bug Repellent Works Better Than Deet.”