When I think about picnics and fireworks this weekend, something else comes to mind: big, thirsty mosquitoes. Besides being a nuisance with their buzzing and biting, mosquitoes are health concerns because of their capability to transmit diseases such as West Nile virus.

If you know you will be outdoors where mosquitoes are a possibility, it is best to protect yourself by wearing pants and a long-sleeved shirt, although the insects’ mouthparts can pierce through thin fabric.

Better protection from mosquito bites is achieved with the use of repellents. These materials do not kill insects, they only make the user less attractive to the little buggers. Products designed to keep mosquitoes out of an area (candles, ultrasonic electronic devices, etc.) are generally less effective. There are also many old wives’ tales regarding things you can eat or rub on your skin, but your best bet is to use a product that is known to work and has been well-tested.

There is plenty of research available regarding the effectiveness of mosquito repellents – so if you plan to sit outside to watch the show this weekend, here is the latest information on insect repellents.

There are four active ingredients available that have registered with the Environmental Protection Agency. Registration requires efficacy testing and human safety testing. These products are:

DEET (N,N-diethyl-m-toluamide)

Picaridin (KBR 3023)

Oil of Lemon Eucalyptus* or PMD (synthesized version of oil of lemon eucalyptus, CANNOT be used on children under 3 years of age)

IR3535

According to the Centers for Disease Control and the EPA, there are no health concerns associated with the normal use of DEET, and the material is not classified as a human carcinogen.

If you use the above-mentioned products, please remember to read and follow all label instructions – they are written for your safety. Perspiration, high humidity and swimming reduce effectiveness. You should also avoid using products that contain sunscreen and insect repellent in one – the combination typically reduces repellent effectiveness by about 30 percent. Apply sunscreen, then spray on repellent, or apply repellent only to your clothing.

Still looking for something a little more natural? Natural does not always mean safer, but there are some products that have proven effectiveness even though they are not registered with the EPA. One of the key elements of effectiveness is how long a repellent provides benefit to the wearer. Many products that are on the market are effective for only a few minutes after application, and in a couple of cases, the repellents even made the user more attractive to insects.

The best nonsynthetic products in research trials were:

¢ Bite Blocker for Kids (2 percent soybean oil, effective for 1.5 hours)

¢ Natrapel (10 percent citronella, effective for 20 minutes)

¢ Herbal Armor (combination of several oils, effective for 19 minutes)

¢ By comparison, DEET products are typically effective for 2-5 hours.

Skin reactions are possible when applying any product, especially if material contacts eyes. If you suspect a reaction when using an insect repellent, call a Poison Control Center at (800) 222-1222.

If you have more questions about insect repellents or other gardening issues, call the Douglas County Extension Master Gardener hot line at 843-7058 or e-mail dgemg@sunflower.com.

– Jennifer Smith is the Douglas County Extension AgentHorticulture for K-State Research & Extension. She can be reached at 843-7058 or smithjen@ksu.edu.