Greenlaurel: Any Ideas For Zapping Mosquitoes Without Using Chemicals?

Share the News

The Asian Tiger mosquito was brought to Maryland from Japan in 1985, most likely in tires. Photo via Wikimedia Commons.

Reader Ann D. recently submitted in a question that many others may be wondering: How do you get rid of annoying skeeters without chemicals? With the West Nile and Zika viruses back in the news, and the little buggers now out in full force in Baltimore, it’s time for mosquito 101. 

We used our phone-the-experts card to learn some surprising mosquito facts and prep measures: Actions homeowners can take to reduce mosquito populations on their property, the risks associated with mosquito-killing chemicals and the best toxic-free options to keep bug bites at bay. Newer integrated pest management techniques — namely starting with non-chemical actions as a first line of defense and keeping toxic options as a last resort — can be easily implemented in your own yard.

Eliminate Mosquito Nurseries

According to Brian Prendergast, Maryland’s chief of mosquito control at the Department of Agriculture, Maryland is home to 60 mosquito species. “The Asian Tiger Mosquito is the common nuisance mosquito in Maryland,” he said. “This mosquito variety doesn’t travel far. Therefore, controlling local mosquito breeding grounds, coupled with protecting yourself from bug bites, can make a difference.”

Your first line of defense is to eliminate breeding grounds to reduce the number of adult mosquitoes. You’ve probably heard by now that mosquitoes breed in tiny amounts of water as small as a bottle cap. If your domicile’s gutters aren’t clean and trap water, or if there’s standing water on or near your property, mosquito nurseries are nearby.

“To control mosquito larvae, first dump any and all standing water on and nearby your property,” said Prendergast. “Pay special attention to your gutters and to the rippled plastic downspout drains. Yard waste, tarps, toys, tire swings can all trap water, too. Then treat remaining water areas that can’t be eliminated — for instance, a rain barrel — with larvicide blocks or pellets.”

Bti, short for Bacillus thuringiensis israelensis, is a natural bacterial compound sold in pellets, blocks and granules; insect larvae feed on the Bti and then die. These products, which are safe for aquatic life, can be found at all garden stores and online. The slow-release types can last for about 30 days. Mosquito Dunks is a commonly sold brand.

Commercial pest control outfits also offer natural oil repellents that can sprayed on plants to deter mosquitoes.

The mosquito larvicide Bacillus thuringiensis israelensis (Bti) is naturally occurring and can be purchased in pellets and granules.

If a neighbor’s property continually harbors standing water and your neighborly negotiations aren’t solving the problem, lodge a complaint with Baltimore City’s 311 service. Based on the situation, the 311 system will alert the appropriate Baltimore City department, which will then address the situation directly with the offending property owner.

Managing Adult Mosquitoes

Killing adult mosquitoes is trickier and can be more toxic. If you’re a parent or are considering parenthood, it’s smart to know the risks associated with mosquito killing chemicals, and wise to be up to speed on the latest Zika virus precautions.

The Maryland Pesticide Education Network, a nonprofit promoting healthy alternatives to toxic pesticides, offers a deeper dive into learning about less toxic mosquito and pest control options. The network’s first line of defense in choosing less toxic methods to repel mosquito bites outdoors is to: 

  • Wear long sleeves and light natural citronella oil candles.
  • Spray exposed skin with natural eucalyptus oil and Picardin bug sprays. Both have been found to effectively repel mosquitoes. Whole Foods, Wegmans, and MOM’s Organic Market offer several good bug spray options. (Read up on Deet repellent, especially if you’re pregnant.)
  • Run fans near your outdoor sitting areas so that mosquitoes are unable to land on your skin.
  • Visit Maryland Pesticide Education Network’s mosquito management tool kit for more information.

Mosquito Chemicals and Your Health

If you choose a commercial service like Mosquito Squad to spray adult mosquito-killing chemicals at your property, it’s key to understand the potential negative health consequences

“The most important factor people should understand is pesticides, including the versions that kill adult mosquitoes, are toxic to children,” said Ruth Berlin, founder and executive director of the Maryland Pesticide Education Network. “Our kids are exposed to pesticides on a daily basis. Research and studies are linking pesticide use, even in low doses, to a host of negative health consequences including attention deficit hyperactivity disorder (ADHD), cancers and diabetes.”

Pyrethroids and pyrethrins are some of the most widely used mosquito chemicals, and are often found in sprays targeting adult mosquitoes. They’re also a point of concern for environmentalists and health professionals.

The Environmental Protection Agency is currently reviewing these chemicals’ impact on human health. Dosage and limited exposure are critical to understand. Also, this class of mosquito chemicals is highly toxic to aquatic life and honeybees. 

Berlin said children and pregnant moms are most vulnerable, because pesticides can enter undeveloped fetuses through breast milk and then disrupt development. Kids’ smaller sizes mean pesticides can have a larger affect in small doses.

Berlin added, “It’s important to understand that [just because] a pesticide [is] registered with the EPA doesn’t mean it’s been approved for safety.”

Dialing up your knowledge of a chemical’s dosage is key.

“Labels are the law in Maryland. Pesticide labels and directions should be closely read and followed by homeowners,” said Dennis Howard, program manager of pesticide regulation at Maryland’s Department of Agriculture.

If you take the time to analyze pesticides warning labels, you may find the list of consequences isn’t for the faint-hearted. Howard explained that many complaint calls into his department are from homeowners who didn’t follow a pesticide’s application directions correctly. 

Zika Virus

According to Michelle Mendes, a spokeswoman for the Baltimore City Health Department, Baltimore has seen 16 cases of travel-related Zika virus. In all of the cases, the subject contracted Zika while traveling in places with infected mosquitoe populations. To date, Maryland and Baltimore governmental agencies report there have been no local mosquito Zika virus transmissions.

“The Zika virus is an all-hands-on-deck issue, and Zika virus prevention is key,” Mendes said. “There is no Zika vaccine, making preventing Zika virus infection even more critical. Pregnant women are advised not to travel to places where the Zika virus has infected mosquitoes.”

For more updates about the Zika virus in Baltimore, read here.

Plants the Repel:

Greenlaurel’s update 6/18/17: Thank you to the several readers who commented about a point that I had missed: Several plant varieties that naturally repel skeeters. This article is informative about the many species which include: Basil, Catnip, Garlic, Geranium, Lavender, Lemon Balm, Marigold, Peppermint, Penny Royal and Rosemary. This weekend, I used a large fan near our patio and sprayed natural bug repellent purchased at MOM’s and no mosquitoes. I added BTI pellets to a fountain, too. 

Follow me

Laurel Peltier

Laurel writes the monthly environmental GreenLaurel column. A graduate of UVA's MBA program, she spends her time with her family and making "all things green" interesting. She co-wrote the Abell Foundation Report detailing Maryland's dysfunctional energy supplier marketplace and the negative outcomes for low-income households.
Laurel Peltier
Follow me

Share the News


  1. Some Europeans plant begonias in their window boxes as a natural mosquito repellent. It’s certainly worth having a few around your back patio or deck.

  2. There is really no reason to use a poison in the air or in our water or in our soil. The chemical companies are poisoning the earth, or food, and all humans. Even using Roundup for weeds should be against the law. All poisons run off into our water supply, into the ocean, and into our soil and kill everything, including our honey bees.

  3. Weren’t we all due to be dead by West Nile Virus by now? Wasn’t Zika to shrink our heads? SARS, EBOLA, Killer Bees?….fun stories, but always a bust!

Comments are closed.