Fast Facts about Mosquito Prevention and Control around Schools

Here are a few facts that you can use and share with those in your district about mosquitoes, mosquito control, and West Nile virus.

The most important single thing a school district can do is make sure school grounds are not contributing to your local mosquito populations.  Check water catchment basins, storm drains, low areas, and equipment storage yards, athletic and playground equipment, especially, for places where water might be caught and held.  Drain or treat with Bt dunks, or Altosid granules–both Green category insecticides.

Mosquitoes typically rest in vegetation or other shaded sites during the day.  If you have areas of vegetation or doorways where mosquitoes are a noticeable problem, consider treating such sites with a residual pyrethroid spray.  This would be a Yellow category treatment and should be limited to known problem areas.  Insecticides like deltamethrin, cyfluthrin, bifenthrin, and lambda-cyhalothrin can provide up to six weeks control on vegetation or building surfaces.  They can be applied via hand-held pump sprayer, backpack mist blower, or power sprayer to doorways and trees, shrubs and ornamental grass around buildings and entryways.  Do not allow students or staff into treated areas until sprays have thoroughly dried. Remember students cannot enter an area that has been treated with a Yellow Category product for 4 hours.

If the city or your district wants to apply ULV insecticides for pretreating sporting venues, posting and notification requirements must be followed and Yellow category justifications filed, as with any use of Yellow category product.  ULV treatments usually use synergized pyrethrins (Green for products with less than 5% piperonyl butoxide), resmethrin or permethrin (Yellow).  Mosquito control with such sprays is short-lived (few hours to a day) and should be conducted only when wind is less than 5-10 mph.

When it comes to IPM for mosquitoes, don’t forget educating students, parents and staff.  The district should consider notifying parents and students advising them to wear repellent to school or evening sporting events.  Use of repellents on school grounds is something each school district must decide on.  Personal use of repellents is not prohibited or really addressed by state school IPM regulations; however, they are addressed through the Department of State Health Services who considers repellents as part of an over the counter medication.  If you have done so, visit with your district’s head nurse make sure she/he is aware of your IPM program and the efforts you, your staff and your pest control contractor are doing everything they can do to help prevent mosquitoes.  The Texas Department of State Health Services and many local mosquito control authorities have useful educational fliers and websites (see below) that parents should be aware of.  School districts have a useful role to play in getting mosquito awareness information out to our communities.  Consider linking this information in your school district’s website.  Check out McKinney ISD for theirs

Some quick facts about mosquito life cycle, breeding, and water sources:

  • Once mosquitoes find a suitably polluted puddle of water, they lay eggs.  Eggs take about a day to hatch and the larvae 5-8 days at 30 degrees C (86 deg F).  Once they pupate it’s another 36 hours before the adult emerges.  So its 10-14 days typically for development.  Standing water must remain for about that length of time before it is likely to breed mosquitoes.
  • Clean water is not so much an issue, but if rain water is mixed with leaves and/or soil and sits in the sun for a week or so, it gets pretty attractive for mosquitoes. In addition, water where fish are present, such as a pond or permanent stream is not usually a big source of mosquitoes.

Remember the 4 D’s

  • DUSK/DAWN- Stay indoors at Dusk/Dawn.  This is the time of day that mosquitoes are most active.
  • DEET-Use insect repellents that contain Deet when going outside, especially at times closer to dawn or dusk when mosquitoes are most active.
  • DRAIN – Remove all areas of standing water.  Examples are pet dishes, birdbaths, and water dishes under potted plants.  Repair faulty French drains.  Remove debris from rain gutters.  Mosquitoes will breed in this debris since it is normally damp under the debris.  Remove all piles of dead leaf material from under trees and shrubs.  This also is a breeding site.
  • DRESS– Avoid being bitten by mosquitoes by wearing light colored long sleeved shirts and long pants when going outside.


The Dept. of State Health services has been sending out emails to school nurses and administrators.  However, at AgriLife Extension we are also providing you this information to ensure everyone knows what you can do.

Need a mosquito management plan – check out this link

Need a poster, flyer, or other information to hand out to teachers, parents or students, including a sample letter you can send home to parents  – check out our link

Need additional information about West Nile Virus or other infectious diseases – check out the Dept. of State Health Services website at

Dr. Mike Merchant has a couple of very good YouTube videos on mosquito prevention and control – talk to your IT department about allowing you to view these very short informative videos.

For Frequently Asked Questions about aerial spraying for mosquitoes, see

Mosquito Safari is an Extension website with general information about mosquito identification, biology and control, including an interactive tour of common mosquito breeding sites, great site to share with teachers, parents and students.

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