Consumer Reports tests repellents that contain deet or other active chemical ingredients, like picaridin and oil of lemon eucalyptus.

To see how effective each repellent is panelists, who were willing to stick their arms into cages filled with disease-free mosquitoes, were enlisted.

Earlier years of testing have shown that if a repellent does well against mosquitoes, it generally tends to do well against ticks.

So which repellents work best? It’s not about which brands performed better, but more about the concentration of the active ingredients.

Testers found concentrations of deet at 25 to 30 per cent are really the best to keep you protected.

Off Deep Woods Sportsmen Insect Repellent IV Dry with 25 per cent Deet performed excellently against mosquitoes. Consumer Reports' Best Buy was Ben’s, with 30 per cent Deet.

Many consumers are worried that deet might not be safe, but CR says there’s a lot of evidence to show that when you follow the directions on the label and you use it properly, deet is very effective and safe.

Consumer Reports also tested repellents that use natural ingredients like citronella, peppermint and soybean oil to keep pests away. These products were not as effective.

The Right Way to Apply Repellents

Proper application and use is essential, both for maximum protection and to avoid possible side effects, including skin or eye irritation. That means:

• Apply repellent only to exposed skin or clothing (as directed on the product label). Never put it on under clothing.

• Use just enough to cover and only for as long as needed; heavier doses don’t work better and can increase risks.

• Don't apply repellents over cuts, wounds or irritated skin. When applying to your face, spray first on your hands, and then rub in, avoiding your eyes and mouth - using sparingly around ears.

• Don't let young children apply. Instead, put it on your own hands, and then rub it on. Limit use on children’s hands because they often put their hands in their eyes and mouths.

• Don't use near food, and wash hands after application and before eating or drinking.

• At the end of the day, wash treated skin with soap and water, and wash treated clothing in a separate wash before wearing again.

• If you're planning to use repellents on your clothes, note that most of the ones we tested damaged leather and vinyl, and some of them stained synthetic fabrics.

Don't Use Combination Sunscreen-Insect Repellent Products

Consumer Reports experts are not fans of combo products—sunscreen should be reapplied every 2 hours, which could overexpose the user to the chemicals in repellents.

(With files from Consumer Reports)