Summer evening, the temperature has cooled down a little bit. You are out enjoying yourself, a cool drink in your hand, some light breeze flowing through your hair, life is good. Then you hear it, the buzzing sounds of the dreaded mosquitoes! You try to swat at them, only to miss and spill your drink, and end up with red itchy bites on your face, arms, and legs.
Mosquitoes are definitely one of the most annoying insects in the world. In addition to stealing our blood, they also spread diseases such as Zika, Dengue Fever, Malaria, West Nile Encephalitis… There are over 3000 species of mosquitoes in the world, and the United States has over 173 species.
The mosquitoes are constantly adapting to new environments and spreading into new habitats. Aedes aegypti, the type that spreads diseases like yellow fever, dengue, and Zika, was originally from sub-Sahara Africa and is now common in the United States. Anopheles gambiae, the type that spreads malaria, can breed in small spaces, like in a flower pot in a city apartment. It has also adapted to biting people earlier during the day, as many places have used mosquito nettings at bedtime.
Mosquitoes generate their much-hated buzzing noises by flapping their wings when flying and can flap up to 1000 times per second. The purpose of the buzzing is actually to help them find mates. Females mosquitoes are larger than male ones, and their buzzing sounds have a lower pitch as they move their wings slower. They can go in stealth mode as well. Mosquitoes sense the buzzing with the Johnston’s organ on their antennas. Females choose mates based on how well the males can tune their wing beat frequencies to females’.
Female mosquitoes bite humans to produce eggs using the protein in human blood. They can lay up to 3,000 eggs in just a few weeks. They like the smell of carbon dioxide and the smell of sweat, which contains lactic acid. They prefer dark colored clothing like black and red. After a blood meal, the female mosquito lays about 200 eggs, then she will seek another blood meal. A female mosquito only needs to mate once, and then can lay eggs for the rest of her life. Mosquitoes usually don’t fly higher than above 25 feet in the air, but they can be found in high altitudes (8000 ft in the Himalayas) and low altitudes (2000 ft underground mines in India). Mosquitoes usually operate around 3 mile radius from where they were incubated, although there are mosquitoes that travel up to 100 miles from their breeding spot.
There are many ways to kill mosquitoes and to prevent their proliferation. We will discuss some of the common chemicals that are used. We will also emphasize on many alternative non-chemical ways. Understanding our options is the only way to make the best decisions.
Mosquito fogging is commonly used by homeowners to get some relief when they go out to their yards. The main chemical used is pyrethrins, which can cause health issues for children. It can also cause indiscriminate killing of beneficial insects.
DEET is the gold standard when it comes to mosquito repellents. However, it is a skin irritant and can cause breathing issues or headaches and burning eyes if used inappropriately. Picaridin is an alternative to DEET. It was made to resemble the natural compound piperine produced by black pepper plants. Another chemical recommended by the Environmental Working Group (EWG) is IR3535, which is a synthetic amino acid that interferes with a mosquito’s sense of smell. It is structurally similar to a component of vitamin B5. The Environmental Protection Agency (EPA) has also listed para-menthane-diol PMD (a component of the lemon eucalyptus oil) and 2-Undecanone (a synthetic compound that can be extracted from a variety of plants) as effective mosquito repellents. All of these can be skin irritants, especially in young children. Use with care, and follow the application instructions carefully.
Metofluthrin is an insect repellent that is sold as OFF! Clip-Ons. The clip-on produces a vapor to protect an individual or an area. EWG does not recommend this product due to potential neurotoxicity and inhalation risk. Mosquito incenses usually use pyrethrum (from chrysanthemum plant) or citronella (from lemongrass plant), but again EWG does not recommend its usage due to particulate matter produced that can pose a significant risk to our lungs, especially in an enclosed area. The chemical permethrin can be sprayed on clothing or nets to kill mosquitoes that touch them. However, the EPA lists permethrin as a likely human carcinogen.
Essential oils from plants such as lemongrass, basil, lavender, peppermint, eucalyptus, catnip do deter mosquitoes, but the effectiveness varies, dependent on particular mosquito species involved. Ultrasonic mosquito repellent simply doesn’t work. Electric mosquito zappers kill many beneficial insects. Mosquito Barrier Spray claims to have a 99% concentration of a potent variety of garlic, and is insecticidal to both adult mosquitoes and larvae, without harming humans or other animals. The Center for Disease Control and Prevention (CDC) has not listed it as one of the recommended prevention methods.
SPLAT Bac is a product that is to be used in bodies of water. It has a waxy outer layer with pheromones that attract female mosquitoes to lay eggs in the water. Then the inner layer releases the bacteria Bacillus thuringiensis israelensis, which only kills mosquito larvae, with no risk to humans or other animals.
MosquitoMate uses Wolbachia bacteria to infect male Aedes aegypti and Aedes albopictus mosquitoes. These infected males will cause wild female mosquitoes who mate with them to be sterile. No chemicals or genetic mutations are involved.
SpringStar company’s autocidal gravid Ovitrap also specifically attracts and traps egg-laden female Aedes aegypti and Aedes albopictus mosquitoes. It is another tool to reduce these disease-spreading species.
So in summary, these steps should be taken to maximize your chance of a mosquito-bite free summer.
First, get rid of all mosquito breeding grounds and resting spots. Pour out standing, stagnant fresh water collections. If unable, drop the SPLAT Bac product in the water. Add an aerator to a pond. Trim tall grasses. Hang autocidal gravid Ovitraps around your property.
Secondly, include pollinator plants and free-flowing freshwater features in your landscape. These will attract natural mosquito predators such as dragonflies, damselflies, frogs, birds. Western mosquitofish can be a great addition to a pond.
Thirdly, shower before you go out to decrease the smell of sweat. Minimize your intake of sweets, or take a complex vitamin B supplement to make your body odor less attractive to mosquitoes. Wear light-colored clothing, cover your legs and arms, and use a net for a baby stroller if the mosquitoes are particularly active. Avoid going out during dusk and dawn. Have a fan blowing at your sitting area to blast off any mosquitoes that may get close by.
Lastly, go to the CDC website, and find out if your area has a high incidence of mosquito-borne diseases. If your area does have a high concentration of disease-carrying mosquito species, then used DEET or other CDC/EWG recommended repellents. If your area is low risk, then use the Mosquito Barrier Spray and dab some essential oils on your clothing. Hopefully, now you can finally enjoy the summer in peace while sipping your glass of drink.
Mosquitoes are not crucial to any predator species. August 20th is the current world mosquito day. Let’s work on making August 20th a world mosquito extinction day.