25 Positive Mosquito Traps in Denton County — and Crews Already Fogged South of Argyle Last Week

Before you plan anything outside this week, here's what's changed in your backyard.

As of July 16, 25 mosquito traps across Denton County had tested positive for West Nile virus. That's the season's running total. It came with action: the county ran overnight ground fogging from 9 p.m. to 5 a.m. in unincorporated areas south of Argyle, July 16 through July 22. That operation has wrapped. It was the fifth scheduled ground fogging of the year as of July 16.

The geography is worth a second look if you're in Flower Mound or southern Denton County. One positive trap this season came from an unincorporated pocket sitting between Argyle to the west and Copper Canyon to the east. Another was in the unincorporated area west of Argyle, in the northwestern portions of Harvest. Not distant corners of the county.

Denton County has also confirmed its first human West Nile case of 2026 — a Denton resident diagnosed with the non-neuroinvasive form of the disease. Juan Rodriguez, the county's assistant director of public health and chief epidemiologist, said it plainly: "We're seeing more positive mosquito traps in the last few weeks, indicating an increasing risk for contracting West Nile virus."

The county fogs with ultra-low volume insecticide overnight in unincorporated areas each time a trap tests positive. Incorporated towns — Flower Mound included — run their own fogging protocols. The county's schedule does not automatically cover streets inside town limits. Check with the Town directly if you want to know where Flower Mound stands.

No vaccine exists. No treatment either. Preventing mosquito bites is the whole game. The steps that work are unglamorous and they work.

What to do right now:

• Drain standing water in your yard — birdbaths, flowerpots, and clogged gutters are prime breeding spots.
• For standing water you can't drain, mosquito dunks (BTI briquettes) will treat it without harming other plants or animals.
• Mosquitoes are most active at dusk and dawn. Health officials recommend skipping outdoor activity at those times and, when you are out, wearing long sleeves and pants and using a repellent containing DEET, picaridin, or oil of lemon eucalyptus.
• About 1 in 5 infected people develop symptoms, which typically appear two to six days after the bite: fever, headache, body aches, joint pain, vomiting, or rash. People over 60 face greater risk of severe illness, as do people with cancer, diabetes, hypertension, kidney disease, or a history of organ transplant. If symptoms develop, call your doctor.
• Trap maps, fogging schedules, and area-specific spray maps are at DentonCounty.gov/WNV. The county updates the map weekly.