For mosquito abatement, Tangipahoa Mosquito Abatement District #1 (TMAD) uses an IPM approach. IPM stands for Integrated Pest Management, which simply means that multiple control measures are used instead of a single method. TMAD utilizes Education, Source Reduction, Biological Controls, Larviciding and Adulticiding.
Though some of these methods are limited to Mosquito Control Districts, all of us can take steps to reduce the amount of mosquito breeding sites where we live. Keep in mind that one female can lay 250 eggs in one batch and within one week those can turn into 250 adult mosquitoes in your backyard. Proper source reduction benefits us all.
Education is an obvious first step in any endeavor and is especially important in an IPM program. Citizens can make an impact upon their immediate surroundings, which may not only benefit them but also their neighbors. Proper watering practices, wearing repellent and other steps can all reduce the impact mosquitoes have in our District. (See the "Around the Home" link)
Source Reduction is simply removing or making breeding sites inhospitable for mosquitoes. This can be as simple as changing out water in a birdbath every few days, or can entail extensive drainage practices to reduce the amount of stagnant water available to mosquitoes. The key to source reduction is eliminating standing water.
Biological Controls consist of natural predators of mosquitoes assisting in keeping the population numbers lower. Dragonflies appear to help in reducing numbers, but the extent to which dragonflies are present is limited. Animals such as bats and small birds, like purple Martins, are believed to eat large amounts of mosquitoes, but studies indicate that mosquitoes make up a very small portion of their diets. Mosquitofish, or Gambusia affinis, are small, darkish, guppy-looking fish native to areas from New Jersey to Florida. They have voracious appetites for the larvae of mosquitoes. In certain areas they seem to be quite effective.
Larviciding is the process of controlling mosquitoes when they are in the larval or pupal form. Controlling mosquitoes when they are in the water is an effective approach; because the mosquito is somewhat isolated and known breeding sites can be recorded and routinely monitored. For many districts, this is the bulk of their operations. The following are examples of habitats that are routinely monitored and treated when necessary:
Adulticiding is the process of controlling mosquitoes when they are adults. Adult female mosquitoes are the ones that bite, so ultimately they provide the largest threat to the public welfare. Adulticiding is necessary because larviciding is not 100% effective and sites may be unknown. Also, there are areas that we cannot treat, therefore, mosquitoes have the opportunity to develop without interference.
Adulticiding can provide temporary control of mosquitoes in a given area, but is not practical as the only method of control. Adulticides are used to control adult mosquitoes, prevent the spread of disease and improve the quality of life for people. Only EPA approved adulticides are used and will degrade rapidly under normal conditions.
Ultra Low Volume (ULV) sprayers are mounted on trucks and will be seen spraying throughout the district. This begins at sunset (generally the peak time for mosquito activity) and continues into the evening as weather permits. Sprayers are carefully calibrated to apply the correct material according to the directions on the label.
Aerial ULV applications are reserved for mosquito populations which cannot be effectively controlled by ground ULV treatments. These treatments are performed using a twin-engine Piper Aztec. Applications typically begin after sunset and continue for 1-2 hours.
The spray altitude for aerial applications is 300 feet above ground level at a speed of 140-150 mph, and all spray missions are done in strict adherence to Federal Aviation Administration (FAA) and Louisiana Department of Agriculture and Forestry (LDAF) regulations. The crew consists of an FAA licensed pilot and co-pilot, with the co-pilot being equipped with night vision goggles as an additional precaution.
The plane is equipped with a GPS guidance system that the pilots use to follow a predetermined flight path and spray grid. An onboard computer system interacts with an weather probe to adjust the flight lines through the use of state of the art modeling software to ensure that the application is on target.
The operational swath width is 1000 feet. Spray blocks for a single flight can be up to 15,000 acres. Spray missions are recorded using a flight recorder and can be overlaid on a map.