Mosquito Control

City of Ennis Department of Health Services


October 3, 2023

The Ennis Health Department received a report of laboratory confirmed presence of West Nile Virus (WNV) in mosquitoes collected in the 100 block of Ave D. Our department will immediately initiate adulticide spraying throughout the surrounding area on October 4th, weather permitting, to minimize the risk of human infections. Spraying will be conducted after dusk per the CDC recommendation. 

Thus far in 2023, no WNV human cases have been confirmed in the City of Ennis but the presence of the disease in mosquitoes means that transmission to humans is possible, so residents are urged to take preventative measures. 


Our department utilizes an Integrated Mosquito Management (IMM) approach to reduce the mosquito population. IMM uses a combination of methods to prevent and control both nuisance mosquitoes and mosquitoes that spread viruses like West Nile, The basic components of IMM include source reduction, surveillance, control of all mosquito life stages, as well as community outreach and public education.

Source Reduction

Source reduction is by far the most effective and least expensive way to reduce the mosquito population in your area. This can be achieved by eliminating standing water on your property. 

  • Dispose of any containers that can hold water.
  • Clean your birdbath at least twice a week.
  • Remove old tires from property.
  • Clean your pet's water dishes daily. 
  • Maintain your backyard pool by keeping it chlorinated and free of debris.
  • Avoid overwatering your yard. 


Our staff actively traps for mosquitoes from May through October every year. Each week, eight traps are placed throughout the city and sent to the Texas Department of State Health Services laboratory where they are quantified and tested for vector-borne diseases like West Nile. The data we receive helps us determine if, where, or when enhanced control measures are needed to manage the mosquito population. 

Control of Mosquito Life Stages

Larviciding is extremely effective in reducing the mosquito population when source reduction is not an option. Our list of current larvicides include: 

Adulticiding, or spraying, only occurs once our department receives notification from the state lab of a positive mosquito trap or human case of West Nile Virus. More information about spraying can be found here.

The current adulticide used is  Aqualuer 20-20.pdf

Protect Yourselves By:


            1) Drain standing water around your property.

            2) Wear long sleeves and pants.

            3) Wear repellent when outdoors - DEET.

            4) Reduce outdoor exposure when possible.

To report stagnant water, please contact the City of Ennis Department of Health Services at 972.875.6444.