Protective screening helps mosquito-proof rain barrels

SAN DIEGO – If you’ve got a rain barrel, this winter’s rains have been great. Your barrel is full, you’re conserving water, and you’re watering your garden naturally. And, you’re growing mosquitoes.

Rain barrels are awesome, but if yours doesn’t have protective screening, your rain barrel could also turn into breeding ground for mosquitoes. That includes our native Culex mosquitoes that can transmit West Nile virus from infected birds to people, and invasive Aedes mosquitoes that can transmit Zika virus if they first bite an infected person.

San Diego County Vector Control inspectors say they have found poorly sealed and homemade rain barrels without proper screening infested with mosquitoes.

So check your rain barrel to make sure it has safety screening on it – similar in size to the screens on your windows that keep bugs out of your home – to keep mosquitoes from laying eggs inside the barrel where mosquito larvae can grow. Also, look to see if there are areas on the outside or the top of your rain barrel where water can pool up. Remember, mosquitoes can breed and create new mosquitoes in very tiny amounts of water.

Chris Conlan, a supervising vector ecologist with the County, said all people – even those who don’t have rain barrels – should inspect their properties and homes and dump out standing water to make sure mosquitoes can’t breed. That’s especially important in the case of the invasive Aedes mosquitoes, which are known for living and breeding very close to people – in backyards and even inside homes.

Conlan said getting bitten by a mosquito doesn’t necessarily mean a person will get sick from any disease.

“We actually have lots of species of mosquitoes here that can’t carry any disease,” Conlan said. “And even the ones that can transmit disease are not, except in extremely rare situations, born carrying them. They have to bite an infected animal or person first to be able to pass a virus or disease along. But it’s still annoying to get bitten by any mosquito.”

Following are a few steps people can take to keep their rain barrels safe:

• It’s always best to use a container that has been specifically created to be a rain barrel – as opposed to, say, a makeshift trash can – that are designed to keep bugs and debris out.
• Use mosquito-proof screen – the same kind of mesh you can find on your window screens – to seal openings that could allow mosquitoes into your rain barrel.
• Keep barrel lids and connectors sealed tight to keep out bugs (especially check openings where rain gutters flow into your barrel).
• Be sure to regularly inspect your rain barrel to get rid of any water that could pool up on the outside and create a place where mosquitoes can breed.

For more information about mosquitoes and how to protect yourself, visit

www.sandiegocounty.gov, click on "Departments," click on "Environmental Health," click on "Menu," click on "Pests" and click on "Mosquitoes."