Introduction
Since the discovery by Sir Ronald Ross in 1897 that mosquitoes transmit malaria, the control of mosquitoes has assumed significance far beyond the federally accepted goal of protecting the quality of life by reducing the hordes of biting insects. No longer would devastating outbreaks of Malaria, Yellow Fever and Dengue Fever in the United States and elsewhere go unchallenged due to ignorance of their means of transmission. Realizing there now existed a means to obtain a measure of public health protection that previously was not available, citizen groups began conducting referenda to establish special taxing districts to fund organized mosquito control activities. In the ensuing years, mosquito control personnel refined their methods through applied research and assisted federal and state agencies in developing certification criteria to ensure conformance to stringent safety standards. The result – the most technically proficient, professional vector control agencies in the world.
This success did not come about in a regulatory vacuum. Since its inception, the Environmental Protection Agency (EPA) has regulated mosquito control through enforcement of standards instituted by the Federal Insecticide Fungicide and Rodenticide Act. This legislation mandated documentation of extensive testing for public health insecticides according to EPA guidelines prior to their registration and use. These data requirements are among the most stringent in the federal government and are met through research by established scientists in federal, state and private institutions. This process costs registrants several million dollars per product, but ensures that the public health insecticides available for mosquito control do not represent health or environmental risks when used as directed. Indeed, the five or six adulticides currently available are the selected survivors of literally hundreds of products developed for these uses over the years. The dosages at which these products are legally dispensed are at least 100-fold less than the point at which public health and environmental safety merit consideration. To be sure, literature posted on the websites of the EPA Offices of Pesticide Programs, Centers for Disease Control and Prevention (CDC), American Association of Pesticide Safety Educators and National Pesticide Telecommunications Network emphasizes that proper use of insecticides by established mosquito control agencies does not put the general public or the environment at unreasonable risk from runoff, leaching or drift when used according to label specifications.
Even with these safeguards, organized mosquito control agencies go to extraordinary lengths to accommodate individuals who, for varying reasons, prefer their property not be sprayed with approved public health insecticides. When surveys indicate the need for adult sprays, they are approved, planned and conducted with special regard to the concerns of chemically sensitive persons. Personal notification of chemically-sensitive individuals of spray times in addition to using Global Positioning Systems (GPS)/ Global Information Systems (GIS) technology to reduce the likelihood of drift over unauthorized areas are but a few of the means utilized to ensure mosquito control serves the entire public spectrum.
The complexities involved in effectively and safely controlling the few dozen harmful species among the 167 different mosquitoes found in the United States are often profoundly misunderstood. As early as 1905, mosquito control pioneers recognized the value of a diversified approach to control, integrating surveillance, source reduction, personal protection, and chemical and biological control. Since 1950’s, control programs have progressively adopted the use of nationally registered public health larvicides and adulticides to further exploit mosquito vulnerabilities within an increasingly environmentally friendly context.
That tradition continues today. In fact, the American Mosquito Control Association has established a formal partnership with the EPA investigating means of improving effective mosquito control while reducing reliance upon public health insecticides.
This Pesticide Environmental Stewardship Program (PESP) has the full and active support of the entire mosquito control profession. The integrated mosquito management methods currently employed by organized control districts and endorsed by the CDC and EPA are comprehensive and specifically tailored to safely counter each stage of the mosquito life cycle. Larval control through water management and source reduction, where compatible with other land management uses, is a prudent pest management alternative – as is use of the environmentally friendly EPA-approved larvicides currently available.
When source elimination or larval control measures are clearly inadequate, or in the case of imminent disease, the EPA and CDC have emphasized in a published joint statement the need for considered application of adulticides by certified applicators trained in the special handling characteristics of these products. The extremely small droplet aerosols utilized in adult mosquito control are designed to impact primarily on adult mosquitoes that are on the wing at the time of the application. Degradation of these small droplets is rapid, leaving little or no residue in the target area at ground level. These special considerations are major factors that favor the use of very low application rates for these products, generally less that 4 grams active ingredient per acre, and are instrumental in minimizing adverse impacts.
The safety profiles of public health insecticides are under increasing scrutiny because of concerns with how specialized application technology and product selection protect the exposed public and environment. In fact, well over 2,000 peer-reviewed scientific studies in various national and international refereed journals since 1980 have documented the safety and efficacy of these public health insecticides at label rates in addition to their application techniques. Despite intense pressures to eliminate the use of public health insecticides, the Center of Disease Control and Prevention, World Health Organization and other public health organizations agree that it is essential that these products remain available for disease prevention and that editorial or irresponsible misrepresentation of the risks involved not lead to the greater risk of not having them available when truly needed. They simply must remain available for the control of vectors in the times of even greater public health emergency that are sure to come. The recent emergence of West Nile Virus has underscored this need for safe, effective mosquito control to meet unforeseen threats.
The continued increase in worldwide tourism and trade virtually guarantees further challenges from exotic diseased requiring ready control expertise to prevent their spread and establishment. We must remain prepared to meet these challenges – our citizens deserve no less.
The mosquito control profession enjoys a long and proud legacy of community service in its pursuit of improved quality of life and a society free from the ravages of mosquito-borne disease that have afflicted our country in times past and present. This goal remains the primary focus and is fully consistent with the very finest traditions of public health.