What to do about mosquitoes

Mosquitoes can carry West Nile virus

Mosquito activity can occur year-round in Southern California because of the warm climate. Mosquitoes can survive in sheltered areas such as storm drains, sewers and other warm, protected spots, then become active again when conditions are right.

Mosquitoes can develop from eggs to biting adults in about a week, so it is important to remove standing water around your home or yard, especially after rainfall.

Stagnant water in ditches, drains, gutters, pools, plant saucers, buckets, toys, trash cans and even small backyard containers can become a mosquito breeding source.

Mosquitoes do not fly far from their water source, which means they may be coming from your yard or a nearby property. If you are getting bites, check your property carefully for standing water.

How West Nile virus spreads

West Nile virus is most commonly spread to people through the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. There are no licensed vaccines or medicines to prevent or treat West Nile virus in people.

Symptoms of West Nile virus

Most people infected with West Nile virus do not develop symptoms. About 20% of people who are infected develop mild symptoms, which may include:

• Fever
• Headache
• Body aches
• Joint pain
• Vomiting
• Diarrhea
• Rash

Most people with mild illness recover completely, but fatigue and weakness can last for weeks or months.

Less than 1% of people infected develop severe illness affecting the central nervous system, which may require hospitalization or result in death. Seek immediate medical attention for symptoms such as high fever, neck stiffness, muscle weakness, confusion or tremors.

Two common types of mosquitoes

• Culex mosquitoes, also known as common house mosquitoes, can spread West Nile virus. They are most active from dusk to dawn and need standing water to lay their eggs.
• Aedes mosquitoes, often called “ankle biters,” are aggressive day-biting mosquitoes that prefer people. Their eggs can survive for months on the dry surface of a container and hatch when water is added.

Take these steps to protect your family

• Remove standing water from clogged rain gutters, rain barrels, buckets, discarded tires, plant saucers, toys and anything else that can hold water for more than a few days.
• Scrub containers thoroughly to remove mosquito eggs along the waterline.
• Maintain swimming pools, spas and ponds properly.
• Change water in pet dishes, birdbaths and other small containers at least once a week.
• Request mosquitofish from your local vector control district for ornamental ponds.
• Use an EPA-registered insect repellent when outdoors where mosquitoes may be present.
• Check window and door screens and repair or replace them as needed.