Mosquito Season in Collin County: Where They Breed and What You Can Do

When is mosquito season in Collin County?

Mosquitoes in Collin County are mainly a warm-season problem, building in spring with rain, staying active through summer and often surging again after fall rain. Exact timing depends on temperature and rainfall. A wet May and a rainy September tend to matter more than the calendar date.

North Texas has a humid subtropical climate with hot, humid summers and mild winters. Roughly 35 to 38 inches of rain falls in a typical year, and it often arrives in bursts. Each burst fills containers and low spots, and a new cohort of mosquitoes can follow within days to a couple of weeks.

Extreme heat can slow mosquito development. The Dallas-Fort Worth area averages 17 days a year at or above 100 degrees F, with the average first 100-degree day on July 1 and the last on August 27. A dry spell during that stretch can reduce the number of natural breeding sites, but irrigation keeps some alive, so the lull is rarely complete in suburban yards.

Mild winters mean mosquitoes are not absent for long, and warm spells can bring a few back early. Our month-by-month pest calendar places mosquitoes alongside the other pests that follow the same weather.

Which mosquitoes are common around Plano?

Two groups are most often discussed in North Texas: Culex mosquitoes, which breed in dirty or stagnant water such as clogged drains and retention ponds, and Asian tiger mosquitoes, which breed in small containers and bite during the day. They need different habits to control, so it helps to know which one is biting.

Culex mosquitoes are most active at dusk and after dark. They favor stagnant, organically rich water such as clogged gutters, catch basins, retention ponds, buckets and neglected pools. They are the group most often discussed in connection with West Nile virus, though there are no case counts on this page, and anyone seeking numbers should check the local health departments.

Asian tiger mosquitoes are small, striped and aggressive daytime biters. They lay eggs in tiny amounts of water, including bottle caps, plant saucers, tarps, tire sections and the cups of bromeliads, and they usually travel only short distances from where they hatched. That means the source is often within a few dozen yards of where you are bitten, which is good news for a homeowner willing to look.

The table below summarizes the difference. It is a general guide, and a technician can help identify what is biting you.

Where do mosquitoes breed around creeks, ponds and gutters?

In Plano, mosquitoes breed in any water that stands for about a week: slow creek backwaters, HOA retention ponds with weedy edges, clogged gutters and storm drains, plant saucers, tarps and low lawn spots. Greenbelts add habitat, but most biting around a house usually comes from containers within a few yards of the door.

Plano is crossed by creeks such as Rowlett Creek, Duck Creek and, in Murphy, Maxwell Creek, and greenbelts run through many subdivisions. Oak Point Park and Nature Preserve covers about 800 acres beside Rowlett Creek. After heavy rain, the backwaters and pools along these corridors hold water that can support mosquito larvae. Moving water is generally less attractive to them than slow, shallow edges.

HOA retention ponds and drainage channels are a second source. A pond with floating plants or algae at the edge gives larvae cover, and aerators or fountains can discourage them by keeping the surface moving. Ponds on common ground are usually the HOA's responsibility, so residents who see problems are better off reporting them to the board or property manager.

At the house itself, the usual culprits are simple. Gutters that are packed with leaves hold water along the roofline. Flower pot saucers, plastic toys, wheelbarrows, tarps and folds in pool covers all collect rain. Low spots near downspouts, and areas where irrigation overspray pools, can keep water for days.

Irrigated lawns do not cause mosquitoes on their own, but a sprinkler that runs into a depression or against a fence line can create standing water that lasts. Our guide to HOA rules, sprinklers and pests explains how irrigation and landscaping affect the whole pest picture.

• Clogged gutters and downspout elbows that hold leaves and water.
• Plant saucers, buckets, toys, tarps and any container left outdoors.
• Birdbaths and fountains that are not refreshed weekly.
• Low lawn spots and areas where sprinklers leave puddles.
• Retention ponds and creek margins with weeds, algae or debris at the edge.
• Neglected pools, hot tubs and covers that sag and hold water.

What can residents do about standing water?

Tip out or cover anything that holds water, clean gutters, refresh birdbaths weekly, fix leaking faucets and sprinklers, fill low spots and keep ponds circulating. Because eggs hatch within days of rain, a weekly walk around the yard is the habit that works best, and it costs nothing.

Source reduction means removing the water. It is the oldest and most reliable approach because it cuts off the life cycle at the egg and larva stages. A weekly ten-minute walk is realistic for most households and works best if it follows a rainy period.

Some container water can be treated rather than removed. Water in a pond or large basin that cannot be emptied is often treated with larvicides that target larvae, or stocked with mosquito-eating fish. Check local guidance before using any product in a water feature, particularly if there are fish or wildlife.

For adult mosquitoes, fans on a patio help because mosquitoes are weak flyers, and long sleeves and an EPA-registered repellent protect you when you go outside at dusk. Window screens that are intact keep mosquitoes out of the house, so repair torn screens before the season starts.

If an HOA pond, creek bank or neighbor's yard seems to be the source, report it. In Collin County, the Collin County Health Care Services office is a place to ask about public-health concerns, and your HOA board can address common-area ponds.

How does professional mosquito control fit in?

A technician can inspect the property for breeding sites, treat vegetation where adult mosquitoes rest and treat larval habitats that cannot be emptied. It lowers adult numbers for a period but does not replace removing standing water. The price is explained and approved before any treatment begins.

Yard treatments typically target the shrubs, fence lines and shaded areas where adults rest during the day. A technician may also place larval treatments in water that cannot be drained. Results depend on the weather, because heavy rain can wash products away and new breeding sites appear with every storm.

This is why a treatment plan usually includes the checklist above. Our mosquito control page describes how visits are typically structured. A property with a pond, a heavy greenbelt border or many shaded beds may need more frequent attention than a small lot with few containers.

Cost depends on the size of the lot, the vegetation, how many visits are needed and the number of breeding sites. We do not publish a price on this page. Any figure should be explained and approved before treatment begins.

If you want a technician to take a look, call (855) 974-4733. Phones are answered 24/7, and a local technician can be scheduled the same day when one is free.

Why does standing water matter for health, and where do I get local information?

Some mosquitoes carry viruses, including West Nile virus, which has a history in North Texas. We do not quote case numbers here. For current counts, advisories and guidance, check Collin County Health Care Services, Dallas County Health and Human Services and the Texas Department of State Health Services.

Mosquito bites are usually only an annoyance, but some mosquitoes can transmit disease, and public-health agencies track this through the warm season. Surveillance results, spraying announcements and advice change from year to year, which is why a local health department is a better source than an article that may be out of date.

The practical advice from public-health agencies is consistent: use repellent, wear long sleeves at dusk where possible, repair screens and remove standing water. If you are pregnant, immunocompromised or older, or if you are concerned about a symptom after a bite, talk to a doctor.

Pet owners should also think about heartworm, which mosquitoes transmit to dogs and cats. A veterinarian can advise on prevention. Our flea and tick control page covers other pet-related pests.