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Mosquito Control

Mosquitoes can develop in any standing water that is present for more than five days. To reduce the mosquito population around your home and property, eliminate all standing water and debris. 

Standing Water

  • Pool cover that collects water, neglected swimming pool, hot tub or child's wading pool.
  • Birdbath (clean weekly) and pool stocked with fish.
  • Any toy, garden equipment or container that can hold water.
  • Flat roof without adequate drainage.
  • Clogged rain gutter (home and street).
  • Leaky faucet or pet bowl (change water daily).
  • Uncovered boat or boat cover that collects water.
  • Missing, damaged or improperly installed screens.
  • Tree rot hole or hollow stump.
  • Junk and discarded tires (drill drain holes in bottom of tire swings).

Other Solutions

  • Get rid of tin cans, bottles, jars, buckets, drums and other containers, or keep them empty.
  • Empty your plastic wading pool weekly and store it indoors. Make certain your swimming pool is properly maintained and the cover stored so it won't collect water.
  • Don't let runoff water from your air conditioner accumulate in shady areas. 
  • Repair faulty septic fields.
  • Change water in vases holding flowers or cuttings weekly - or grow cuttings in sand.
  • Don't dump grass clippings, branches or other items in storm creeks.
  • Mosquitoes rest in vegetation and other protected places; keep the grass cut and bushes trimmed.
  • Wear light colored clothing and a white hat as mosquitoes are attracted to dark colors. Wear long sleeves and long pants to minimize exposed skin.

Mosquito Control Products

Homeowners can purchase biological mosquito control products at garden centers, home supply and other retailers. Bacillus thuringiensis israelensis (Bti) is the active ingredient; it destroys the intestinal lining of the mosquito larvae. Another product contains methoprene which prevents the larvae from developing into adults. Barrier sprays are also available that can be sprayed on vegetation where mosquitoes rest.  Check out various mosquito repellent products and follow label instructions.

Mosquito Breeding

  • All mosquitoes need water in which to pass their early life states. Adult flying mosquitoes frequently rest in grass, shrubbery or other foliage, but they never develop there.
  • Some mosquitoes lay their eggs in standing water where they hatch in a day or two. Other mosquitoes lay their eggs in old tires, tin cans, or other water-holding containers in which they may remain unhatched for weeks or months until they are covered with water. 
  • With both types of mosquitoes, the "wigglers" or larvae grow quickly and turn into "tumblers" or pupae. Soon the skin of the tumbler splits open and out climbs another hungry adult mosquito.
  • Mosquitoes can pose a health threat by transmitting mosquito-born diseases as encephalitis, dengue, malaria and dog heartworm.

Surveillance Program

We operate a disease surveillance program and a mosquito control service to residents of unincorporated areas of the County. These control services are also available to residents of incorporated areas on a contract basis.

If you wish to spray your yard to control adult mosquitoes, your Public Health Department, the University of Missouri Extension Center or your local hardware store or garden center can recommend insecticides that are effective and approved by the EPA (Environmental Protection Agency). Be sure to follow all label instructions carefully.

Remember, treating adult mosquitoes is only a temporary solution. Elimination of breeding sites and stopping mosquitoes while they are still in the water is much more effective and economical.


To report mosquito problems
contact us during regular business hours 
Phone: 314-615-0680



If you are interested in seeing what general section of the county is sprayed for mosquitoes on a particular night of the week, click here. If you would like to hear specific information listing where spraying will occur tonight, call 314-615-4284 (615-4BUG). A recorded message is updated daily between 4:00 p.m. and 6:00 p.m. Spraying begins at sunset.