Mosquito Control Programs: Public or Private?

Stephanie Richards, PhD, Medical Entomologist

PUBLIC MOSQUITO CONTROL

Government-funded (municipal or county) “public” mosquito control programs may be organized stand-alone entities or components of other programs (e.g., Environmental Health, Public Health or Public Works). Funding status, availability and the number of employees working in these programs varies widely by geographic region. Some regions may have a property tax–based system set up to pay for mosquito control, while other areas depend on state legislatures to earmark funding for these programs. During non-crisis times, government funding for mosquito control may be reduced or eliminated, thereby reducing the trained workforce and leaving some areas unprepared when a mosquito-related crisis occurs.

In general, well-funded, long-term public programs use surveillance tools such as Centers for Disease Control and Prevention carbon dioxide–baited light traps (mosquitoes active at dusk/dawn) or BG Sentinel traps (day-active mosquitoes) to collect host-seeking mosquitoes (all mosquito ages detected) and/or gravid traps to detect older mosquitoes that have already blood fed and are ready to lay eggs. Programs also may regularly collect mosquito larvae and identify mosquitoes to species. Some programs may utilize serology data obtained from sentinel chicken flocks stationed throughout their areas to monitor arboviruses that are a threat to public health, such as Eastern equine encephalitis virus or West Nile virus. Based on data collected from these methods, programs may decide to use larvicides, biological control methods (e.g., mosquito fish) and/or adulticides (truck-mounted ultra-low volume machine [mosquitoes active at dusk/dawn] and/or backpack mist blower [mosquitoes active at dusk/dawn and day-active mosquitoes]) to target potentially dangerous mosquito populations. In order to utilize these tools, well-trained personnel must exist in a well-funded and sustained mosquito control program. Underfunded programs may rely primarily on public education campaigns for prevention of mosquito-borne disease and/or respond to community-based mosquito complaints through site visits and/or adulticide treatments.

PRIVATE MOSQUITO CONTROL

There are a variety of fee-based “private” mosquito control programs available for people to utilize, especially in areas where public mosquito control program services are minimal/underfunded or absent. Mosquito-related services provided by private companies and associated fees vary between companies, i.e., small-scale local scope to national/international companies. Individual homeowners or homeowner associations in communities may choose to contract with private companies for mosquito site assessments and treatments.

In general, private control programs apply barrier sprays (via backpack mist blower) of adulticides to vegetation around customers’ properties approximately every three weeks. Some private programs offer misting systems that are affixed to homes and apply adulticides on a regular basis. Larvicides may also be used by some private companies to treat potential egg-laying sites, and these fee-based services may include customer education on how to reduce mosquito egg-laying sites on properties. While some private mosquito control companies may favor moving toward mosquito surveillance as a component of their programs, their customer base is not necessarily neighborhood and/or community-wide (different format than public programs), hence making comprehensive surveillance-based targeted control more difficult. In areas where homeowner associations fund private mosquito control, surveillance-based targeted control may be more feasible so that only some problematic areas in a community would be periodically targeted for control based on surveillance findings. In regions where public mosquito control programs are underfunded or do not exist, private programs may assist in mosquito control efforts, although not every community can afford this private service.

SUCCESSFUL MOSQUITO CONTROL PROGRAMS

Regardless of the source of funding for mosquito control programs, an integrated mosquito management approach is recommended. Control of mosquitoes at the immature stage by source reduction (reducing/removing mosquito egg-laying sites), biological control or larvicides is the first line of defense. If necessary, adulticides can be used to suppress adult mosquito populations. Proactive surveillance-based (e.g., trapping, mosquito identification/enumeration) targeted control methods should be practiced by certified pest control professionals.

Public education about mosquito biology, source reduction and biological control should be included in mosquito surveillance and control programs. Evaluation of the effectiveness of control measures, including periodic assessment of insecticide resistance (e.g., bottle bioassays) is an essential component of any mosquito control program.

MOSQUITO CONTROL ENTITIES (PUBLIC AND PRIVATE) SHOULD SEEK TO DEVELOP AND SUSTAIN PARTNERSHIPS WITH THE LOCAL COMMUNITY, UNIVERSITIES AND BUSINESSES TO PROMOTE LONG-STANDING PROGRAMS THAT BENEFIT PUBLIC HEALTH. PUBLIC AND PRIVATE MOSQUITO CONTROL ENTITIES MAY CONSIDER PARTNERING WITH EACH OTHER, ESPECIALLY IN ANTICIPATION OF POTENTIAL DISEASE OUTBREAKS AND/OR NATURAL DISASTERS SUCH AS HURRICANES/FLOODING THAT MAY CALL FOR INCREASED CONTROL MEASURES TO PROTECT HEALTH. PUBLIC HEALTH OFFICIALS SHOULD HAVE UP-TO-DATE KNOWLEDGE OF THE EXISTING REGIONAL DISTRIBUTION AND CAPACITY OF LICENSED MOSQUITO CONTROL OPERATORS TO RESPOND TO A MOSQUITO-BORNE DISEASE OUTBREAK OR OTHER MOSQUITO-RELATED ISSUE IN ADVANCE OF A PUBLIC HEALTH THREAT.

Responding to an epidemic (reactive control) is much more costly than sustained funding for a proactive surveillance-based mosquito control program. Even in years of fiscal challenges, communities should petition for continued mosquito surveillance, public education/participation and targeted control.

Dr. Stephanie L. Richards is an Associate Professor of Health Education and Promotion in the Environmental Health Sciences program at East Carolina University. She received a B.S. in Biology and M.S. in Environmental Health from East Carolina University. She completed her Ph.D. in Entomology with a minor in geographic information science at North Carolina State University. She completed her post-doctoral work in Arbovirology at University of Florida, Florida Medical Entomology Laboratory.