West Nile Fogging Cycle Just Wrapped in Northwestern Harvest — Here's What Comes Next

The county's mosquito trucks finished their last pass through northwestern Harvest on June 26. If you live near Cleveland-Gibbs Road and Old Justin Road — or anywhere in that stretch west of Argyle — the fogging is done. That's good. But it doesn't mean the threat is.

Denton County Public Health confirmed that a mosquito trap at the intersection of Cleveland-Gibbs Road and Old Justin Road tested positive for West Nile Virus, triggering three rounds of truck-based, ultra-low volume fogging between 9 PM and 5 AM. The Harvest trap is one of two near Argyle to test positive for WNV this summer — the other was along Hwy 377 at the end of May — and it's part of a broader pattern: five Denton County traps have now come back positive in the 2026 mosquito season, with no confirmed human cases yet.

Five traps. No human cases yet. That's the window.

Fogging kills the adult mosquitoes that are out right now. It does nothing to the eggs sitting in your gutters, the larvae in your birdbath, or the water pooling in a flower pot saucer on your back porch. Mosquitoes can grow from egg to biting adult in about seven days. One week after the trucks leave, the yard that wasn't dealt with is a new breeding ground.

And August — historically the most active month for West Nile in Texas — is still ahead.

About 1 in 5 people infected with West Nile will develop symptoms at all, according to the CDC. Most of the other 80 percent never know they had it. The roughly 1 percent who develop the neuroinvasive form — encephalitis, meningitis, paralysis — face a much harder road. No vaccines. No treatments. Prevention is the whole game.

What you can do this week is concrete. Drain anything that holds water: birdbaths, clogged gutters, flower pot saucers, old tires, pet water bowls. Mosquitoes only need a bottle-cap's worth of stagnant water to reproduce. For standing water you can't drain — a decorative pond, a low spot in the yard — drop in a BTI briquette (often sold as a "mosquito dunk"). They kill larvae before they hatch and won't harm pets, birds, or fish.

Flower Mound residents have a head start here: the Town has been handing out free mosquito dunks this season, two per household, at Town Hall on FM 1171. Bring proof of residency. If you haven't grabbed yours yet, now's the time. You can also call Flower Mound Environmental Health Services at 972.874.6340 if you need help identifying or treating standing water on your property.

Stay inside at dawn and dusk when mosquitoes are most active. If you're out, wear long sleeves and use an EPA-registered repellent — look for DEET, picaridin, or oil of lemon eucalyptus on the label.

Watch the county's trap map at DentonCounty.gov/WNV. It updates weekly. If another positive trap shows up near Harvest or in Flower Mound proper, another spray cycle follows. The county's response is fast — but only as fast as the surveillance data allows. Residents reporting dead birds and standing water complaints help fill in what the traps miss.