Mosquito Repellents

AgriLifeLogo June 2015 Newsletter#2

Mosquito Repellents

With all the rain we’ve been getting, mosquitoes are emerging in large numbers. We have many different mosquito species in Central Texas and their activity times can vary. Some mosquitoes are most active during dusk and dawn hours while others are active during the day. Since mosquitoes are capable of transmitting many diseases, it is important to protect yourself when you are outside.

First off, it is best to wear long pants and a long sleeved shirt in light colors. Repellent should only be applied to clothing and exposed skin. Do not apply it underneath clothing. If you want to apply repellent to your face, spray your hands with repellent and rub it onto your face. Do not spray repellent directly into your face or near eyes or mouth. Make sure to apply repellent outdoors. Do not allow children to handle repellents. Wash hands before eating, smoking or using the restroom.

The Center for Disease Control (CDC) recommends using a product registered with the EPA (Environmental Protection Agency) containing one of the following active ingredients: DEET, picaridin, IR3535 and some of the products containing oil of lemon eucalyptus.

DEET, also known N,N-diethyl-m-toluamide or N,N-diemethylbenzamide, was developed by the U.S. Army in 1946 to protect soldiers in insect-infested areas. Pesticides containing DEET have been used by the general public since 1957. Products containing DEET should not be used on children younger than 2 months of age. DEET has a slight odor and may have a greasy feel to some people. It may damage plastic, rubber, vinyl or synthetic fabrics. DEET may be irritating to the eyes and skin for some people. DEET comes in a wide variety of concentrations, so choose the one that will work best for your situation.

Picaridin was first made in the 1980’s and resembles a natural compound called piperine (which is found in plants used to produce black pepper). Picardin has been used in Europe and Australia for many years, but has only been in the U.S. since 2005. Picaridin is non-greasy and is odorless.

IR3535, or 3-[N-Butyl-N- acetyl]-aminopropionic acid, ethyl ester, was developed in the mid- 1970’s and became registered for use in the U.S. in 1999. It is registered as a biopesticide by the EPA because it is functionally identical to a naturally occurring substance (an amino-acid). It may dissolve or damage plastics and may be irritating to the eyes.

Oil of lemon eucalyptus (OLE) or PMD (para-menthane-3,8-diol) are essentially the same thing; PMD is the synthesized (lab created) version of oil of lemon eucalyptus. “Pure” or “essential” oil of lemon eucalyptus is not labeled as a repellent and has not undergone testing and should not be used as a repellent product. OLE/PMD has been on the market in the U.S. since 2002. OLE/PMD should not be used on children younger than 3 years of age. The natural product (OLE) has known allergens within it while the synthetic version (PMD) has less of a risk to allergens. This product is classified as a biopesticide. OLE/PMD has a varying range of residual, some offering about 20 minutes of protection while other products may last up to two hours.

Many factors play into how long a repellent will last for a person. Some of these are:

  • The concentration (or percent of active ingredient) of the product. You can find the percentage on the product label.
  • Person’s attractiveness. Some people are more attractive to mosquitoes than others (and no scientific research has proven that it is because of eating garlic, taking vitamin B, using tobacco products, etc.). A person’s genetic code plays a large part on what makes a person so attractive to mosquitoes.
  • Frequency and uniformity of application. In other words, how often is the repellent applied and how good of coverage did you get?
  • Activity level of the person. The more active the person is, the more sweat they produce which can cause the repellent to wash off the surface of the skin.

As a word of caution, there are products that combine sunscreen and insect repellent. The CDC recommends that if you need sunscreen and repellent, that you choose two separate products. Sunscreen should be applied more often than repellents.

For more information or help with identification, contact Wizzie Brown, Texas A&M AgriLife Extension Service Program Specialist at 512.854.9600.

The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by Texas AgriLife Extension Service or the Texas AgriLife Research is implied.
 Extension programs serve people of all ages regardless of socioeconomic level, race, color, sex, religion, disability, or national origin.