When mosquito season starts in Maryland
Maryland mosquitoes become active when temperatures consistently hit 50°F — typically late March or early April in the Columbia–Howard County area. Peak season runs May through September, but mild falls can extend activity into October. Waiting until you're already being bitten means you're treating an established population rather than preventing one.
Species that breed locally
Two species cause the most problems in Howard County:
Aedes albopictus (Asian tiger mosquito)
Aggressive daytime biter, breeds in small containers — bottle caps, clogged gutters, leaf pools. Very common in Columbia's wooded neighborhoods.
Culex pipiens (common house mosquito)
Dusk/dawn feeder, breeds in stagnant water. Main carrier of West Nile virus in Maryland.
Standing water sources homeowners miss
Mosquitoes need less than a tablespoon of water to breed. Common sources that get overlooked:
- Clogged gutters holding leaf debris and pooled water
- Tarps, furniture covers, or trash can lids collecting rainwater
- Low spots in the lawn that don't drain after rain
- Kids' toys, sandboxes, and play equipment left outside
- Birdbaths not refreshed every 48–72 hours
- French drain outlets that hold water between storms
What professional treatment covers
A barrier spray program targets resting sites — shrubs, dense ground cover, shaded areas along fence lines — where mosquitoes spend most of their time. Treatments are applied monthly during peak season and break down naturally between visits. A properly timed first treatment in April means peak-season populations are significantly smaller before they build.
Learn more about seasonal programs on our mosquito treatment service page for Columbia, MD and Howard County.