Plus, How to Request Mosquitofish Service and Do Bug Zappers Work on Mosquitoes?
As California businesses begin the process of reopening and expanding capacity, the Contra Costa Mosquito & Vector Control District (District) is happy to announce the District is once again open to the public.

  • The District is located at 155 Mason Circle, Concord, CA 94520. 
  • Office hours are 8:00 a.m. - 4:30 p.m. Monday - Friday.
The District is open to the public
Contra Costa County Residents may visit the District during regular business hours to drop off biting or stinging pest samples for identification by our Laboratory staff; however, residents can no longer pick up mosquitofish at the District. The District now provides a Mosquitofish Service.

How to Request Mosquitofish Service

During the COVID-19 pandemic, the District has enacted many changes—some temporary and some permanent. Being closed to the public was a temporary change. The District's new Mosquitofish Service is permanent.

Now, Contra Costa County residents no longer have to travel to the District office, sometimes from long distances, for mosquitofish. Instead, county residents can sit in the comfort of your own home and call the District at 925-685-9301 or visit the District's website to request our Mosquitofish Service. Once a county resident requests the Mosquitofish Service, a District employee will follow up to confirm the details, and then visit the residence within five business days.
While on the property, the District employee will inspect the water feature and determine if mosquitofish are the appropriate response to the mosquito issue at hand.
  • For example, if adult mosquitoes are flying out of the water feature, mosquitofish alone will not solve the problem, and the District employee may treat the water feature.
  • If young mosquitoes of an appropriate age are in the water, the District employee may place mosquitofish in the water feature and provide the resident with information on how to care for the fish.
A District employee first inspects the water feature,
then prepares to place mosquitofish in the pool.
In 2020, the District received 131 requests for Mosquitofish Service. Halfway through this year, the District has already received 133 requests. According to District Operations Supervisor David Wexler, the service has not only proven to be popular with residents, but it is also beneficial when it comes to the District's efforts to reduce the risk of mosquito-borne disease.

 "While the District employee is on the property to inspect the water feature, the employee will also provide a thorough inspection of the surrounding area to make sure the water feature is not the only source of mosquito production on the property. That provides us with an opportunity to reduce the risk of mosquito-borne disease for the resident and nearby neighbors," said Wexler.

So, if you are a Contra Costa County resident who needs mosquitofish for your backyard pond, fountain, retired swimming pool, or other residential water feature, request the District's Mosquitofish Service today.

It's a Good Idea to Think Twice Before Using One
District technician Heidi Budge says she's noticed an increase in the number of bug zappers she's seen in Contra Costa County since last year. Subsequently, she's been spending a lot of time explaining to county residents that bug zappers really aren't the best way to prevent mosquitoes and could actually attract more insects to the property because of the bright light.

Night-flying insects of all sorts, including mosquitoes, are drawn to the light. And with mosquitoes that can fly up to 20 miles in Contra Costa County, one bug zapper can attract mosquitoes from miles around. According to the District's Scientific Program Manager Steve Schutz, Ph.D., once mosquitoes are in your yard, they may be more attracted to you, than the zapper.
A bug zapper in a backyard
"If you really want to use a bug zapper, be sure to keep it in the far corner of your yard and away from doors and windows. That way any mosquitoes or other insects attracted to the light (which are more often beetles and moths than mosquitoes) are farther away from you and your house. When it comes to preventing mosquitoes, it's more effective to dump out any standing water on your property to deny mosquitoes a place to lay their eggs." said Schutz, Ph.D.

If, after dumping out any amount of water in outdoor buckets, plant saucers, discarded tires, and any other container you can identify, you still experience mosquitoes on your Contra Costa County property, contact the District to request Mosquito Service. That's a much better way to reduce the risk of the mosquitoes you already have instead of inviting more mosquitoes and other insects to your yard to visit that bright light.
Contra Costa Mosquito & Vector Control District, an independent special district and public health agency, is located at 155 Mason Circle in Concord. Contact the District to report mosquito and vector problems online or at (925) 685-9301.