DEET AKA N, N-diethyl-m-toluamide
DEET is the most well known and commonly used repellent in the United States. I have found it to be very effective against mosquitoes,gnats,chiggers and somewhat effective against ticks and biting flies.
Some drawbacks of DEET are that it has a distinctive odor that some people dislike and heavy applications can give the skin a sticky oily feel. In addition some people who are sensitive to the chemical suffer skin rashes. DEET will also damage or dissolve some plastics and synthetic materials including eyeglass lens so care must be used in its application.
Products with higher concentrations of DEET won't provide greater protection than low concentration products when initially applied however they don't need to be reapplied as frequently.
Deet will last for days on clothes that are not washed. A more permanent treatment that will endure repeated washings can may be done with Permethrin. DEET was introduced commercially in 1955. It is considered by the FDA to be safe for use on humans 2 years of age or older. DEET is also known as N,N-diemethylbenzamide.
There are also somewhat more expensive composite or broad spectrum repellents that incorporate DEET with R-326 and MGK-264 which are said to be more effective in repelling biting flies.
Picaridin [1-Piperidinecarboxylic acid]
Picaridin has only recently been approved for sale in the United States fairly recently so it does not have the track record of DEET. Its benefits compared to DEET are that it is relatively odorless, does not feel sticky or oily and is safer for synthetic materials.
Picaridin is said to be quite effective against most biting insects however it is currently only available in the U.S. in a 7% concentration not the 20% which is standard in Europe. This means that it must be reapplied frequently, perhaps every two hours.
In use since 1998 in Europe, Picaridin was developed by Bayer. It is also known as KBR3023 and Bayrepel. Picaridin is currently sold in the U.S. as "Cutter advanced ".
Oil of Lemon Eucalyptus
Oil of Lemon Eucalyptus is a plant based repellent that is about as effective as a low concentration DEET formulation. Not for use on children under three years of age.
Applying insect repellent
- Do not apply to lips, under nose, or eye lids. If you get insect repellent in your eyes, flush them with water immediately.
- Wear hat sprayed with insect repellent to prevent tick from finding a home in your hair. A hat may affect your heat signature and confuse ticks that might other wise drop on you.
- Apply repellent to top of socks to discourage ticks and chiggers from crawling under the cuffs of your pants.
- To apply repellent to your face and ears, spraying or apply to you hand and use your hand to put it on.
- If you are using a sun screen in addition to an insect repellent - apply the sunscreen first and then the insect repellent. Be aware that the use of the repellent may reduce the (SPF)(Sun Protection Factor) of the sun screen you are using by as much as a third.
Permethrin is a contact insecticide which is used on clothing, bedding, mosquito netting and screens. It is highly effective at killing ticks, mosquitoes and other insects as well as acting as a repellent. Permethrin bonds readily to fibers and will provide long lasting protection if applied correctly.
I have used permethrin treat clothing on many occasions and have watched many a tick race up my leg to find a patch of bare skin only to slow down and fall off dead.
Permethrin is considered to be fairly non toxic to humans, however direct application of permethin to the skin is neither recommended or effective as it is quickly absorbed and metabolized on contact with the skin.
An Aerosol spray application of 0.5-percent permethrin to clothing or fabrics will remain effective for up to 6 weeks and 5 or 6 washings. A soak treatment as used by the U.S. Military with a solution of 40 percent permethrin may last up to 50 washes.
Be sure to follow all label directions on whatever product you use.
Marginal or worthless methods of dealing with insect pests
Citronella candles and torches are basically ineffectual in terms of repelling mosquitoes. Mosquitoes coils can be somewhat effective if used in an interior space but screens are generally better.