Where the water actually is on a New Orleans lot
Begin with the parts of the property that never fully dry. In a city taking 64 inches of rain a year, that list is longer than most people expect: the low corner of the yard, the alley between houses, the courtyard drain packed with leaves, the space under a raised house where the ground stays damp. Then the intentional water. Fountains that have stopped circulating are excellent Culex habitat, and so is any cistern or rain catchment left open. These deserve larvicide rather than dumping, since the point of having them is to hold water. Then the accidental containers, which produce the daytime biters: plant saucers, a sagging tarp, an upturned lid, the tray under an outdoor plant stand, a wheelbarrow parked upright. Aedes glues eggs to their inner walls above the water line, where the eggs survive up to eight months of dryness. Finally, look at the curb. Street catch basins are outside your control but very much inside the two mile range the CDC gives for Culex, which is why reporting them is part of the job.
Two mosquitoes, two completely different fixes
Use the clock to tell them apart. Bites landing at midday in a shaded courtyard mean container breeding Aedes aegypti or albopictus. Those mosquitoes never travel far, so the water producing them is within a few blocks, usually much closer, and the fix is emptying and scrubbing containers rather than spraying anything. Bites that begin as the sun goes down and continue into the night mean Culex. This group breeds in stagnant water heavy with organic matter, ranges up to two miles, and carries West Nile virus. Louisiana's 38 neuroinvasive cases in 2024 came through this route. The practical difference is who has to act. An Aedes problem is almost always solvable on your own property or with a conversation over the fence. A Culex problem frequently is not, because the source is a drain, a canal, or an abandoned building's water. Spending money on the wrong one is the most common way people end up paying for a service that never fixes the evenings.
Prevention for raised houses and courtyards
A raised house solves flooding and creates mosquito habitat at the same time. The space underneath stays shaded and humid all day, which is precisely where adults wait out the heat before coming out to feed. Keeping that area clear of stored containers, tarps, and debris removes both the resting cover and any water that would otherwise sit there unnoticed. Screening the vents and lattice helps more than people expect, and it pairs with getting the window screens right. Old sash windows in New Orleans move with humidity, so screens that fit ten years ago may not seal now. Courtyards need a different habit. They are enclosed, shaded, and full of potted plants, which means dozens of saucers and a drain that clogs with leaves. Make the weekly round of the courtyard a fixed routine, and clear the drain each time. At 77 percent humidity, none of this water evaporates on its own. Anything that collects will still be there in a week, which is exactly how long a generation takes.
Renters, landlords, and drainage in older buildings
In a New Orleans rental the split usually falls along the line of what is attached to the building. Gutters, downspouts, drainage in a shared courtyard, a defunct fountain, an unmaintained pool, and the screens on the windows are the owner's. Portable water is the tenant's: plant saucers, buckets, the recycling bin, a cooler left open on the porch. When you report a problem, describe the water and the location precisely, in writing, with a date. A note about a courtyard drain that has held water for nine days gets a faster response than a complaint about mosquitoes. For owners, repair beats recurring treatment on cost alone. Clearing a blocked drain once costs less than paying for barrier applications every three weeks through a season that stretches toward December. Screens on old wooden windows are the same calculation. Where the source is a vacant neighboring property, neither party can fix it directly, and a report to the parish is a better use of the afternoon than another quote.
How to read a Gulf Coast treatment plan
Ask for the plan in writing and check three things before the price. First, does it name larvicide, say where it goes, and give a reapplication interval. Source reduction and larviciding are what the EPA describes as the core of integrated mosquito management, with adult treatment as a supporting piece rather than the service itself. Second, what calendar does it cover. Along the Gulf, biting continues into November and December, so a plan ending in September leaves a real part of the season open. Ask what visit frequency looks like in the heaviest rainfall months compared with winter. Third, what happens between visits. New Orleans storms refill everything at once, and a plan that includes a return trip after heavy rain is worth more than one a little cheaper that does not. Then weigh the walkthrough itself. A provider who spent half an hour finding your courtyard drain and the damp ground under the house has understood the property. One quoting from the street is selling a schedule.