|BG Sentinel traps are among the most popular|
traps for sampling nuisance biting mosquitoes
like Asian tiger and yellow fever mosquitoes.
Yet, monitoring remains important to any PMP wanting to implement an IPM/IMM program. Without monitoring you don't know what mosquitoes are biting, what diseases are circulating, and when human risk is highest. So what's a mosquito technician to do?
Good news. Many counties, mosquito abatement districts and cities have area-wide mosquito surveillance programs. While not necessarily focused on your customer's property, these area-wide programs are often quite good. Some even provide neighbor-hood level detail in their public reports. They may chart Aedes mosquito numbers collected from traps like the carbon dioxide-baited BG Sentinel trap. And they may provide both Culex mosquito numbers and disease prevalence from gravid traps.
The gravid trap is an especially powerful monitoring tool. West Nile carrying Culex mosquitoes are drawn to these traps like cats to catnip. They are typically baited with polluted water known as "stink water." While every health department has their own formula for stink water, it's usually made by steeping grass clippings in water for 2 weeks or so. The foul smell of the water draws gravid female mosquitoes as they seek stagnant water for egg laying. Gravid traps help health departments measure the number of potential WNV-carrying mosquitoes present. Mosquitoes collected in these traps are also collected into groups, or "pools," and sent to laboratories for virus testing. Some health departments publish this data in up-to-the-week reports that can tell you and your customer about their local, seasonal risk for West Nile and related viruses.
|Gravid traps consist of a tray with "stink water," with a suction|
trap positioned a few inches above the water. Female mosquitoes
drawn to the water for egg-laying are sucked into the trap, where
they are collected, counted and prepared for testing.
There's a lot of data in these reports, but some of the key things I look for include the following. Where in my community has WNV been detected in mosquitoes? How abundant are Aedes mosquitoes (these are the daytime biting mosquitoes most noticed by your customers)? How abundant are Culex mosquitoes (responsible for transmitting WNV to people)? And how is the Vector Index changing?
Most of your customers will likely not be familiar with health department data, nor will they understand its interpretation. But by taking the time to get access to the data, and understanding its significance, your company can serve as an educational bridge to your community. By letting customers know when disease incidence and mosquito abundance is highest, everyone is reminded of when to take special steps to avoid mosquito contact, and the importance of their own mosquito control.
It's often said that information is power. Whether you include residential mosquito control as a special service, or simply an add-on benefit to your regular customers, you owe it to them to be informed about what mosquitoes are doing in your community. A call to your local health department can provide you with a wealth of public health data, that can make you more a powerful advocate for your clients.
Some Texas and national WNV and mosquito information can be accessed online at:
- Dallas County: http://www.dallascounty.org/department/hhs/epistats.html
- Tarrant County: http://access.tarrantcounty.com/en/public-health/epidemiology-and-health-information/health-data-and-information/west-nile-virus/2017-arbovirus-season.html
- Harris County: http://publichealth.harriscountytx.gov/Resources/Mosquito-Borne-Illness
- Travis County: http://www.austintexas.gov/department/vector-control
- National (Centers for Disease Control--will not be as timely as local reports, but offers national insights) https://www.cdc.gov/westnile/statsmaps/preliminarymapsdata2018/index.html