Mosquitoes are not just annoying. Their painful bites cause itchy, red bumps that stay irritated for days. In addition, mosquitoes have the potential to spread diseases, such as West Nile virus and malaria. The mouthwash brand Listerine is touted as a main ingredient in homemade mosquito repellents, but its effectiveness is controversial to say the least.
Listerine as a Mosquito Repellent
Despite the rumors of its effectiveness as a mosquito repellent, Listerine does not work for that use, according to University of Kentucky entomologist Grayson Brown, Ph.D., cited in a 2011 Prevention magazine article. How the myth of Listerine being a mosquito repellent got started may have something do with the fact that it contains eucalyptol, which is often used in botanical insect sprays.
Even though scientific evidence states otherwise, some gardeners still believe Listerine repels mosquitoes. One of them is Arnie Mason, a former broadcaster for radio and television. He uses a mixture that is one-third Listerine, one-third Epsom salts and one-third beer, according to a WECT 6 website article. He adds the mixture to a garden sprayer and then sprays his lawn, trees and bushes with it to keep mosquitoes at bay.
Organic Mosquito Repellents
Having a well-cared-for lawn is one of the best ways to control mosquitoes because they hide in tall grass and weeds. When you regularly mow your lawn and weed your garden, you eliminate the vegetation mosquitoes use to rest and hide.
Installing a bat house also will go a long way in controlling the mosquitoes in your yard. Bats feed on insects and can consume 500 to 1,000 mosquitoes in a single hour.
Another option is to add annual marigolds (Tagetes spp.) to your landscape. Marigolds naturally contain thiophene, which is a compound that can kill mosquitoes.
Bacillus thuringiensis subspecies israelensis, abbreviated Bti, is widely considered an effective treatment against mosquitoes. Bacillus thuringiensis is a naturally occurring bacteria that targets certain insect species and is safe to use around humans, pets and wildlife, including fish.
Bti is available in various forms, such as ready-to-spray and granular. One company's ready-to-spray bottle of Bti needs to be attached to a garden hose, the water to the hose turned on and the resulting Bti-water solution applied in even strokes directly to lawns, trees, gardens and shrubs. If you use the Bti granular form, evenly broadcast it using a lawn spreader at a rate of 5.2 ounces of the granules per 1,000 square feet of ground surface. Apply the Bti when the air is calm and there is no chance of rain for at least six hours after the application. The retreatment directions vary by brand and type of Bti used. For example, the label directions of one brand of ready-to-spray Bti suggests reapplying the pesticide after frequent or heavy rainfall; the label directions for the brand of a granular form of Bti recommends reapplication when the site becomes reinfested with mosquitoes. Obtain the maximum effectiveness of the product you use by following its label instructions.
Even though Bti is considered safe to use, it can cause moderate eye irritation and possible skin irritation. Wearing protective eye-wear, rubber gloves, a hat, socks, shoes, a long-sleeved shirt and long pants when you use a Bti product will help prevent adverse reactions.