ROSENBERG, Texas (Covering Katy News) — Fort Bend County Health and Human Services will conduct aerial mosquito spraying across designated areas of the county from Monday through Wednesday, June 22-24, following County Judge Daniel Wong's declaration of a local public health emergency over extraordinary mosquito populations fueled by weeks of persistent rainfall and widespread standing water.
Fort Bend County Health and Human Services said its Environmental Health Division will conduct the aerial spraying "to control the mosquito population and protect public health." The application of Dibrom Concentrate, an Environmental Protection Agency-approved mosquito control pesticide, will begin around sunset each evening, weather permitting.
Spraying Effort Comes in Response to Judge Wong's Emergency Declaration
Judge Wong declared a local public health emergency on June 16 due to extraordinary mosquito populations affecting large portions of Fort Bend County after weeks of heavy rain left standing water across the area.
Fort Bend County Health and Human Services said the emergency abatement measure follows Wong's declaration "to protect public health by reducing the risk of mosquito-borne disease transmission and other adverse impacts."
The department also noted that treatment areas identified for aerial spraying are subject to change.
Fort Bend County
This map shows the areas scheduled for mosquito spraying by Fort Bend County based on surveillance data, mosquito trap counts, and public health concerns.
Why Some Neighborhoods Are Sprayed and Others Are Not
The aerial spraying operation comes amid questions from residents about why some areas receive treatment while others do not.
Fort Bend County Health and Human Services said spraying decisions are based primarily on surveillance data and public health considerations, not on complaints from individual neighborhoods.
The county's Integrated Mosquito Management program maintains more than 90 mosquito trap locations throughout Fort Bend County. Mosquitoes collected from the traps are counted, identified and tested for diseases such as West Nile virus. Areas showing unusually high mosquito populations or positive virus samples receive priority attention.
The department said adulticide spraying is performed when surveillance detects positive mosquito pools or other disease-related concerns. A mosquito pool is a group of mosquitoes that tests positive for a mosquito-borne virus.
Health officials also monitor environmental conditions, particularly standing water left behind by heavy rains and flooding, which can dramatically increase mosquito breeding. This year's public health emergency declaration followed more than 1,500 mosquito-related complaints and trap collections that reached as many as 5,000 mosquitoes during a single collection period.
Filing a Complaint Does Not Automatically Trigger Spraying
Fort Bend County Health and Human Services said residents' complaints are important and can prompt inspectors to investigate conditions or deploy additional surveillance measures. However, the department said it does not conduct spraying on request or on a fixed schedule.
There are several reasons why a neighborhood may not be included in a spraying operation. Mosquito traps in the area may not show elevated populations, mosquitoes may not be carrying disease, or officials may determine that larvicide treatments and source reduction efforts are sufficient. In some communities, municipalities operate their own mosquito control programs, limiting county involvement within city limits.
Health officials said targeted spraying allows the county to focus resources where the public health risk is greatest, reduce unnecessary pesticide use and protect pollinators and other beneficial insects.
For residents, the absence of spraying in a neighborhood does not necessarily mean the county is ignoring the area. Rather, it generally means county surveillance data has not shown mosquito levels or disease activity that warrant adulticide spraying there.
Health Officials Urge Residents to Follow the '4 Ds' of Mosquito Safety
Fort Bend County Health and Human Services is encouraging residents to take precautions against mosquito bites by following the "4 Ds" of mosquito safety:
- Avoid Dusk and Dawn, when mosquitoes are most active.
- Drain standing water around homes and properties.
- Dress in long sleeves and long pants when feasible.
- Defend against bites by using repellents containing DEET or other CDC-approved mosquito repellents.
The video below provides more information about how the county determines the areas that needed to be sprayed. To see the video in its proper format, click to start and then use the arrows to enlarge it.
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