Now with a new school year starting up, many school districts are asking themselves, "What should we be doing?" Parents will be concerned about their children waiting at bus stops and participating in band and athletics practice. And let's not forget about Friday Night Lights, and weekly football games. What responsibility do schools have to take part in community wide mosquito control? And if you work for a school district, what will you tell parents when they ask what the district is doing to keep their kids safe from West Nile virus?
Perhaps the most important single thing a school district can do is make sure that school grounds are not contributing to local mosquito problems. It's especially important to check water catchment basins, storm drains, low areas, and equipment storage yards, athletic and playground equipment for places where water might be caught and held. If you do pest control in a school district, expand your vision at this time of year to look for and report potential mosquito breeding sites.
If a suspected breeding site is found, report it to your local health department, or if possible, drain the water or treat with it. Effective mosquito treatments include Bacillus thuringiensis (Bt) dunks or methoprene (Altosid®) granules or briquets. Both of these are Green category insecticides.
Treating Mosquito Resting Sites
Mosquitoes are primarily active in the evening and morning. During the day, adult mosquitoes typically rest in vegetation or other shaded sites. We can use this information to reduce mosquito numbers. Treatment of mosquito resting sites can dramatically reduce bites and biting rates in the immediate area of treatment.
If you know of areas of vegetation, or shaded doorways where mosquitoes are a problem, consider treating such sites with a residual pyrethroid spray. Pyrethroid insecticides like deltamethrin, cyfluthrin, bifenthrin, and lambda-cyhalothrin (Yellow category) can provide up to six weeks control on vegetation or building surfaces. These products 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.
Such sprays are probably not necessary on most campuses, but in sites with heavy shade and vegetation, and populations of biting mosquitoes, such treatments may be warranted. If you choose to treat sites like this, remember to post the school 48 hours in advance, and keep students and staff out of treated areas until sprays have thoroughly dried.
Low Volume Treatments
|One of the five planes used to apply mosquito |
sprays over Dallas County this month. (Photo
courtesy of Dallas Morning News and Tom
Most school districts will not engage in ULV sprays, though some cities or mosquito districts may offer the district an option to be included in community-wide spray actions. If ULV insecticides are to be used for campuses or sporting venues, remember to follow posting and notification requirements. Yellow category justifications must generally be filed, because most ULV treatments use Yellow category products like resmethrin or permethrin. Synergized pyrethrin applications may be considered Green, unless the synergizing additive in the spray concentrate (generally piperonil butoxide) is greater than 5% .
The effect on mosquitoes from ULV-applied sprays is generally short-lived (few hours to a day), so they should be used only on special occasions, such as an hour or more before a sporting event. Wind and weather also have an important influence on the effectiveness of ULV sprays, so be sure to measure and record wind speed prior to application and follow label restrictions carefully.
If your campus has been sprayed as part of a community-wide aerial spray campaign, no special precautions should be necessary. However some districts have been making a point to let parents know that school play equipment has been washed after spraying.
Education and Awareness
Ironically for schools, one of the most overlooked components of an IPM program is education. Mosquito season provides an excellent opportunity to get mosquito control information out to the community, as well as raise awareness of your district's IPM program.
One of the most important messages that a school can send is the importance of wearing insect repellent when working or playing outdoors. Consider notifying parents and students advising them to wear a good repellent to school, or at evening sporting events.
Many districts have had questions about whether they can allow students to use repellents on school grounds. Personal use of repellents is not prohibited or addressed by state school IPM regulations. Therefore it is up to each district to decide whether students and staff can bring and use repellents at school. Options include allowing students to bring repellents to a school nurse, and having the nurse apply if needed. Another option might be to allow only cream or non-spray repellent formulations, especially for band and athletic departments in middle and high schools. The time to decide on the appropriate policy, however, is now, before students return to campus. For more information on insect repellents, see the excellent repellent guide put out by the National Pesticide Information Center.
As a public service, consider assisting the Texas Department of State Health Services and other local health authorities get the message out about mosquito control. There are many useful educational materials and websites (see below) that parents should be aware of. School districts can play a useful role in getting mosquito awareness information out to our communities. Consider linking this information in your school district’s website.
Some quick facts about mosquitoes and West Nile virus:
- The southern house mosquito, Culex quinquefasciatus, is the primary carrier of WNV in most of Texas (different species carry the virus in other parts of the country). This mosquito is a container breeder. It prefers to breed in small containers or puddles of standing water.
- Water must stand for 10-14 days to be a problem for mosquito breeding. It doesn't have to be a lot of water, but this is approximately how long it takes for mosquitoes to complete their life cycle at 85-90 degrees F.
- Remember stagnant, polluted (stinky) water is the water that Southern house mosquitoes love. Water where fish are present, such as a pond or permanent stream is not usually a big source of mosquitoes.
- Not all people are equally attractive to mosquitoes. Body chemistry differs from person to person and some of us smell more attractive to mosquitoes than others. Don't assume that because you aren't noticing bites that mosquitoes are not active.
- 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.
- Check out the eXtension school IPM action plan for mosquitoes. If you don't have a plan for mosquito control in your IPM notebook, this may be just for you.
- 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 this link.
- The Department of State Health Services website on school resources
- Frequently Asked Questions about aerial spraying for mosquitoes can answer many concerns parents (and customers) have about community-wide mosquito spraying
- Mosquito Safari is an Extension website with general information about mosquito identification, biology and control, including an interactive tour of common mosquito breeding sites.
- Four new videos on how to mosquito-proof your home
Thanks to Janet Hurley and the Texas School IPM program in assembling much of the information for this post.