With the rainy season behind us, L.A. County residents can expect more than blooming flowers — they’ll likely see a rise in mosquitoes too. According to local experts and biologists, all that standing water left behind by storms has created the perfect breeding conditions for mosquitoes across Southern California.

Unmaintained swimming pools and backyard containers are the top culprits. Just one algae-filled pool can produce up to 3 million mosquitoes per month. Even small items like bottle caps, flowerpots, or rain barrels can collect enough water for mosquitoes to lay eggs.

Two mosquito species are of primary concern:

• Culex tarsalis, known to transmit West Nile virus and St. Louis encephalitis, bites primarily at dawn and dusk.
• Aedes, nicknamed the "ankle biters," are invasive daytime biters that can transmit dengue and chikungunya.

Despite some counterintuitive benefits of heavy rain — like flushing out breeding areas in old storm drains — mosquito control remains critical. Vector control officials urge residents to do weekly inspections around their homes:

• Dump out standing water
• Invert containers that could collect rain
• Keep pools clean and properly chlorinated
• Seal rain barrels

If mosquito activity gets out of hand, local vector control districts, like ours, offer free inspections and treatments.