Re: Africa Aedes Territory shown through RVF virus distribution
Mosquito Control Programs
In response to these potential disease carrying pests,
communities organized the earliest mosquito control programs in the eastern U.S. in the early 1900s.
Eventually, other communities created similar programs throughout the country in areas
where mosquito problems occurred and where citizens demanded action by local officials.
Modern mosquito control programs in the U.S. are multifaceted and include surveillance, source reduction, and a variety of larval and adult mosquito control strategies.
Surveillance methods include studying habitats by air, aerial photographs, and topographic maps, and evaluating larval populations.
Mosquito control officials also monitor mosquito traps, biting counts, and complaints and reports from the public.
Mosquito control activities are initiated once established mosquito threshold populations are exceeded.
Seasonal records are kept in concurrence with weather data to predict mosquito larval occurrence and adult flights.
Some mosquito control programs conduct surveillance for diseases harbored by birds, including crows, other wild birds, sentinel chicken flocks, and for these diseases in mosquitoes.
Source reduction involves eliminating the habitat or modifying the aquatic habitat to prevent mosquitoes from breeding.
This measure includes sanitation measures where artificial containers, including discarded automobile tires, which can become mosquito habitats, are collected and properly disposed.
Habitat modification may also involve management of impounded water or open marshes to reduce production and survival of the flood water mosquitoes.
If habitat modification is not feasible,
biological control using fish may be possible.
Mosquito control officials often apply biological or chemical larvicides, with selective action and moderate residual activity, to
the aquatic habitats.
To have the maximum impact on the mosquito population,
larvicides are applied during those periods when immature stages are concentrated in the breeding sites and before the adult forms emerge and disperse.
Some mosquitoes can fly from flood plains, coastal marsh areas, or protected habitats to impact urban residential areas. In these cases, it is often necessary to apply pesticides to kill adult mosquitoes.
Surveillance data may prompt insecticide applications when mosquitoes are abundant. Applications usually coincide with the maximum adult mosquito activity in urban residential areas.
To be successful,
mosquito control officials must apply insecticides under proper environmental conditions (e.g., temperature and wind) and at the time of day when the target species is most active.
They must also apply these pesticides with
carefully calibrated equipment that generates the proper-sized insecticide droplets that will impinge on adult mosquitoes while they are at rest or flying. If the droplets are too large, they will fall to the ground. If they are too small, the prevailing winds will carry them away from the target area.
Once the insecticide spray mist dissipates, they break down in the environment (generally within 24 hours) producing little residual effect.
Depending on the situation, mosquito control officials may safely apply these insecticides from spray equipment mounted on trucks, airplanes or helicopters.
All insecticides used in the U.S. for public health use have been approved and registered by the EPA following the review of many scientific studies.
The EPA has assessed these chemicals and found that, when used according to label directions, they do not pose unreasonable risk to public health and the environment.
Mosquito control officials
have also developed water management strategies that take advantage of opportunities to maximize the impact of indigenous natural enemies to eliminate immature mosquitoes.
The EPA and CDC encourage the use of these practices wherever they are environmentally sound, effective, and reduce pesticide use.
Integrated Pest Management
Mosquito control activities are important to the public health, and responsibility for carrying out these programs rests with state and local governments.
The federal government assists states in emergencies and provides training and consultation in vector and vector-borne disease problems when requested by the states.
The current interests in ecology and environmental impact of mosquito control measures, and the increasing problems that have resulted from insecticide resistance
emphasize the need for "integrated" control programs.
EPA and CDC encourage maximum adherence to integrated pest management (IPM).
IPM is an ecologically based strategy that relies heavily on natural mortality factors and seeks out control tactics that are compatible with or disrupt these factors as little as possible.
IPM uses pesticides, but only after systematic monitoring of pest populations indicates a need. Ideally, an IPM program considers all available control actions, including no action, and evaluates the interaction among various control practices, cultural practices, weather, and habitat structure.
This approach thus uses a combination of resource management techniques to control mosquito populations with decisions based on surveillance.
Fish and game specialists and natural resources biologists should be involved in planning control measures whenever delicate ecosystems could be impacted by mosquito control practices.
The underlying philosophy of mosquito control is based on the fact that the greatest control impact on mosquito populations will occur when they are concentrated, immobile and accessible.
This emphasis focuses on habitat management and controlling the immature stages before the mosquitoes emerge as adults.
This policy reduces the need for widespread pesticide application in urban areas.
EPA and CDC recommend that professional mosquito control organizations throughout the U.S. continue to use IPM strategies.
Both agencies recognize a legitimate and compelling need for the prudent use of space sprays, under certain circumstances, to control adult mosquitoes. This is especially true during periods of mosquito-borne disease transmission or when source reduction and larval control have failed or are not feasible.
Education
To be of maximum effectiveness, the people, for whom protection is provided, must understand and support mosquito control.
An integral part of most organized mosquito control programs is public education.
It is important that residents have a good understanding of mosquitoes, the benefits realized from their control and the role people have in preventing certain mosquito-borne diseases.
Being aware of pesticide application times is also important for individuals so they may decide on precautions they may need to take.
While this usually involves education of the public through announcements in the media, some control programs have staffs that develop and present educational programs in public schools.
People who are informed about mosquito biology and controls are more likely to mosquito-proof their homes, and eliminate mosquito breeding places on their own property.
