Ground Spraying Vehicle

Public Health has deployed more than 1,000 mosquito traps in various locations throughout Tarrant County

Mosquitoes caught in the traps are brought to Public Health on a regular basis, where they are sorted, and tested for specific chemical markers that can tell us if they are carrying specific pathogens, like West Nile Virus.

When West Nile Virus-positive mosquito samples are found, leaders of the municipality where the positive sample was found are notified. If the positive pool is found in an unincorporated portion of Tarrant County, Tarrant County Public Health will arrange for that area to be ground sprayed, after all appropriate resident notifications have been completed.

We will post ground Public Health spraying notices on this webpage.

This Public Health's interactive map provides locations and details as to when and where ground spraying for mosquitoes will occur or took place in all of Tarrant County.

For detailed information about West Nile Virus, including weekly reports, as well as tips and videos explaining how to deal with mosquitos, visit our Be Mosquito Free page.

About ground spraying

Before any ground spraying takes place, Tarrant County Public Health (TCPH) always recommends residents and individuals take personal measures to protect themselves and eliminate mosquito breeding on their property.

Ground spray notices

Prior to any ground spraying done in unincorporated areas, Tarrant County Public Health will notify residents of those areas about the spraying to take place via signs placed at all entrances to the area. Announcements are also posted on TCPH's website and social media. The West Nile Virus vector interactive map also provides notice.

The responsibilities

Each municipality in Tarrant County is responsible for mosquito abatement (control toward reduction) within their city limits.

TCPH is responsible for mosquito abatement within the unincorporated areas of Tarrant County. 

TCPH works with the municipalities to monitor mosquito activity and offers mosquito control recommendations; although the decision to start/stop any mosquito control activity is given by the governing body of the each municipality.

The process

Most Tarrant County municipalities monitor and trap for mosquitoes with traps TCPH provides free of charge. The trapped mosquitoes are brought to TCPH where the mosquitoes in each trap are sorted, or "pooled" (separated out by species), and tested for the presence of West Nile Virus (WNV) and other mosquito-borne diseases. When a WNV-positive pool is found, TCPH will notify the respective municipality.

TCPH will adulticide (treat for adult mosquitoes) in the unincorporated area where disease in the trapped mosquito pools are found.  

TCPH does not adulticide for nuisance mosquitoes, however TCPH will treat ANY source containing mosquito larvae with various types of larvicide (treatment for larval mosquitoes).

TCPH may adulticide for multiple consecutive nights if it is determined that there is an elevated risk to humans (for instance: multiple positives pools in the same area and confirmed human cases of WNV).

Gravid mosquito trap device

The details

TCPH will larvicide if mosquito larvae is present and no natural predators are found within the body of water.

TCPH has an integrated pest management (IPM) policy for treating mosquitoes.  The IPM was developed using best practice recommendations from the Texas Department of Agriculture, the Texas Department of State Health Services and the U.S. Centers for Disease Control and Prevention (CDC).  The IPM outlines how each TCPH control measure activity is initiated, tracked and recorded, assuring TCPH uses the least amount of chemical to effectively reduce the mosquito population.

TCPH currently employs six Texas Department of Agriculture-licensed personnel in the mosquito abatement program.  

TCPH may contract with local businesses to assist with the task of ground spraying. These contractors are awarded based on criteria established by TCPH during the bidding process that follows TCPH IPM.  The criteria do include but are not limited to,  proof that all personnel are properly licensed to apply insecticides used for mosquito control, and the company is required to provide location, time, date and rate of each application to TCPH.

Public Health hires contractors as needed for ground spraying. They generally use a pesticide that includes permethrin as the active ingredient. We are currently treating unincorporated Tarrant County with either permethrin (Aqua Perm 30 30) or sumithrin (Anvil 2 + 2).

Be aware that each municipality that has its own spraying equipment may use different pesticides.

Tarrant County Public Health's phased response guidelines for mosquito-borne diseases are modeled after the CDC's phased response guidelines for mosquito-borne diseases and may include other applicable community procedures. All actions are subject to change without notice due to organizational priorities, weather or other unforeseen circumstances.


About Aerial Spraying

Should West Nile Virus-positive mosquito pools become excessive --and more people become sick, Tarrant County Public Health will notify the affected region prior to any aerial spraying taking place.

In situations where large scale aerial spraying is necessary, the FDA and EPA-approved chemical Dibrom (also known as Naled) is used.

Aerial Spraying for Mosquitoes in Tarrant County - Frequently Asked Questions


Further information

Tarrant County Public Health Phased Response to Mosquito Surveillance Guidelines

Arboviral Surveillance and Mosquito Control Program policies

A “vector” is an animal that can carry and transmit disease to another animal.  A mosquito is considered a vector of concern because a mosquito can carry and transmit diseases to humans. More on vector control.