The Homeowners Column

The Homeowners Column

Keeping Mosquitoes at Bay

Photo of Sandra Mason

Sandra Mason
Extension Educator, Horticulture
slmason@illinois.edu

Mosquitoes can ruin summer activities. However if we are armed with a basic understanding of mosquitoes and a few good repellents, we can all survive the mosquito attack.

Mosquitoes are best known because of the blood-sucking habits of the females. (Okay gentlemen, go ahead and chuckle.) The females require blood in order to develop eggs. Males do not feed on blood, but live solely on nectar from flowers or moisture from other sources.

Mosquitoes are attracted to large dark objects, so wear light colored clothing. Wear long sleeves, long pants and avoid wearing perfumes. Mosquitoes are more likely to attack active individuals and tend to bite at dusk. Watch out during those late night volleyball games.

The most effective personal repellents are those containing the chemical DEET (the abbreviated name for N, N-diethyl-meta-toluamid) such as Off® and Cutters®. Read and follow label directions. Some people are allergic to DEET and it is toxic if swallowed so it requires very cautious use around children. DEET is best applied to clothing, but it can harm plastics.

Concentrations of DEET vary in products. According to Extension educator Ron Wolford, research reported by Consumer Reports magazine a few years ago found that a 40 percent DEET aerosol "warded off mosquitoes for more than six hours." Products of 20 to 40 percent DEET were nearly as good and protected for up to four hours. Most of the time the lower concentration products are adequate.

Avon's Skin So Soft® can help repel some mosquitoes, but is short lived. DEET is still 30 times more effective than Skin So Soft.® "Natural" repellents that contain citronella or a mixture of citronella, cajuput grass, sassafras, peppermint, myrrh, vanilla and other ingredients seem to work for some people, though their performance in research has been poor.

When using any repellent, don't apply near eyes, on lips or on broken skin; avoid breathing spray, don't use near food and wash repellent off with soap and water when it's no longer needed.

Citronella candles on a patio work in a limited area provided the air is calm and there are candles all around you. Mosquito repelling scented geraniums have very limited if any benefit in repelling mosquitoes, but at least they look nice. Significant amounts of repellent oils can be released when the leaves are crushed, but rubbing the crushed leaves on your skin is risky because of allergy or irritation.

A breeze from an electric fan can help blow mosquitoes off course. Forget the bug zappers. Outdoor electronic bug zappers kill many insects, but very few pests and many beneficial insects. Mosquitoes are not attracted to light. Most of the insects that are attracted to the zappers never make it close enough to be zapped, so you may be actually attracting more insects to your yard with bug zappers. Bats are actually much more helpful in controlling mosquitoes.

Mosquitoes come from larvae that live in standing water in ponds, pools and puddles or buckets, barrels and birdbaths. Make sure you are not compounding the mosquito problem in your landscape. Remove old tires, buckets and other water-holding containers. Change the water in the birdbaths and wading pools at least once a week and clean out or repair roof gutters so that water does not accumulate. Drain or fill puddles or ditches that hold water for long periods of time. In rain barrels use mosquito dunks or pellets containing the bacterial agent Bacillus thuringiensis israelensis. Fish take care of most mosquito larva in ponds.

To see some great looking water gardens minus the mosquitoes, check out the U of I Extension Master Gardener Garden Walk on June 17. Contact the Extension office at 801 North Country Fair Drive in Champaign, 333-7672 or area garden centers for tickets.

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