Repellents come in many forms including chemical sprays, natural lotions, and electronic devices. The most well known repellent is deet (N, N diethyl-m-toluamide). Deet has been studies profusely by the scientific community and there is little doubt that it does work, especially in higher concentrations. It is the most effective and long-lasting repellent that is commercially available. Unfortunately, health concerns have been raised by many researchers since deet is a chemical. These concerns have prompted many to recommend that deet with a concentration of more than 10% should not be applied to children, and that deet should always used sparingly on exposed skin. In a race to develop a natural alternative to deet, many manufacturers have turned to essential plant oils and other substances. Unfortunately, only limited success has been achieved. Those that do offer some mosquito repellence generally have a short effiacy period - in other words, they don't last long. Most are simply ineffective. Citronella is probably one of the best known natural "repellents." Most who have used it will agree that its effectiveness is quite limited. Electronic and ultrasonic devices have also proven largely ineffective.
Deet (N, N diethyl-m-toluamide)
Description: Deet has been scientifically proven to provide the best personal protection from mosquito bites. Deet is available in variety of concentrations ranging from as little as one or two percent to 100%, and is applied directly to your clothing or skin. There is a great deal of concern however, about the effect of Deet on human health, specifically on children. It is generally recommended that children use a concentration of no greater than 10%. It is also recommended to try to avoid the use of Deet, or products containing Deet, directly on your skin as it is a toxic chemical. Rather, it should be applied to your clothing.
Advantages: Proven to be the most effective personal use product/repellent for the prevention of mosquito bites, low cost.
Disadvanges: Human health concerns, does not reduce breeding population (temporary relief), must apply every day you use your outdoor living space (or even several times per day).
Description: These usually come in a bisque tablet or pellet form and can be added to areas of standing water on your property (a pond, for instance) to kill the mosquito lava. They usually use a bacterial agent that only attacks mosquito larva, so they are generally regarded as relatively environmentally safe. Because larvicides only target mosquito hatching on your property, mosquitoes that are hatching on adjacent properties could still enter your yard looking for their next blood meal. For this reason, larvicides are not generally considered a viable overall control solution.
Advantages: Quite effective and environmentally safe in some circumstances.
Disadvantages: Not effective at intercepting mosquitoes migrating to your property from neighboring land to feed.
Mosquito Band Blocking Devices
Description: These bands, or bracelets are worn around the wrist, and release an odor that is reported to confuse mosquitos and make it hard for them to identify you as a target. Mosquitoes will still be present, but bites may be reduced slightly.
Advantages: Inexpensive and easy to wear.
Disadvantages: Effectiveness is very limited.
Ultrasonic & Electronic Devices
Desription: Small ultrasonic electronic devices are meant to be carried on the body and purportedly emit sounds that repel mosquitoes. Some report to mimic the frequency of the wing-beat of a dragonfly (the mosquito's main predator). Many studies conducted in the field and laboratory show that these devices simply do not work or have very limited effectiveness.
Advantages: Inexpensive and unobtrusive
Disadvatages: Effectiveness questionable