How to live with or control mosquitoes

July 02

My wife hates to go outside because she attracts mosquitoes, when I don’t even know there are any around.  Several products are available to repel mosquitoes but how effective are they?  Whether or not they are effective is a good question.  A single test can cost millions.  Some of the tests have been made available to the CDC or EPA.  Test results sent to the EPA are to support registrations of products and may not be available for public  use.  The CDC, Center for Disease Control, has research results and does publish some data for the public.  Below is a summary of products and there relative effectiveness.

By far, DEET-containing products are the top performers and most will last from 2 to 6 hours with a single application. Picaridin is the second most effective product with performance in the 1-3 hour range. Oil of Lemon Eucalyptus are considered botanicals and are often labeled as being “green friendly” (whatever that means!). Cedar oil is employed as a scent to repel mosquitoes. The scant data available suggests that these products only last for 15 to 20 minutes after an application. This can be partially solved by finding a formulation that slowly releases the scent into the air.  There are bracelets or tags that hang on clothing that offer a slow release of one or a combination of the above scents. Citronella is listed on the EPA or CDC lists as a mosquito control product. And some of the new mint oils are also not on the list of effective actives.  A pretty good study, done two decades ago, used citronella candles surrounding test subjects.  The test people got bit as frequently as people some distance away, but with no candles nearby.  However, citronella candles seem to be so entrenched in our culture and used for ambiance with everyone thinking they control mosquitoes.  We will likely continue spending millions a year on the little lanterns and keep buying the oil. 

A unique item was found that supposedly gives off a magnetic or electrical field that keeps mosquitoes away from people.  You simply wear it around your neck and they leave you alone.  My suggestion is to make ankle bracelets incorporating the items so they don’t get my wife’s ankles and legs.  Do these items work?  I really can’t say, but I haven’t invested any money in this company.

Mosquito traps have improved and are recognized as being able to reduce mosquito bites when mosquito populations are medium to low.  The expensive ones that work use CO2, a tiny light and a suction fan to attract, pull in and then kill the mosquitoes.  A rather new method of controlling mosquito activity is modifying air movement! Mosquitoes are very weak flyers and don’t like to travel when air movement is in the 8 to 10 mph range or greater. Therefore, using outside ceiling or side fans in an area can greatly reduce mosquito flight and landing ability.  The fans must be turned to blow on the subjects.  

Our family had a wedding reception at our house last summer.  The weather had been very wet and we had a terrific mosquito problem.  My assignment was to make the yard mosquito free.  The methods I employed were four fold.  First, I used my Black Flag fogger which produces a fog that floats on the air.  Any mosquito will have a minute droplet impinge on their body and the small insecticide dose kills them. The fogger was positioned so the fog drifted across the yard and into the brush and trees around the yard.   Next I directly sprayed the vegetation for several feet around the yard and the lawn so mosquitoes that landed would pick up a lethal dose.  This works, because when resting, mosquitoes land on vegetation and get liquids from the surrounding vegetation.  Third, I made sure any mosquito breeding sites were eliminated or treated so my yard did not provide breeding sites.  Fourth, the day of the reception I treated the yard with a cedar oil product from Green Light, YardSafe Insect Repellant.  The aroma kept new mosquitoes from venturing in to attack our guests.  The cedar oil smell was faintly in the air and lasted throughout the afternoon and evening. No one would object to the pleasant smell.  The result was no mosquitoes at the party.

Do yourself a favor when you plan on going outside. Don’t eat bananas.  Eating bananas makes people attractive to mosquitoes.    They are also attracted to CO2 but we do have to breathe.

The Garden Doc