Cape May County
Freeholder Kristine Gabor
Peter J. Bosak, Ph.D., Superintendent
The Cape May County Department of Mosquito Control's objective is to manage mosquito populations using an integrated control approach according to the New Jersey Health Statutes, Chapter 26:9; stressing environmental safety, economics, efficacy, research and surveillance in order to protect the health and welfare of the citizens and visitors of Cape May County.
The Cape May County Department of Mosquito Control, formerly the Cape May County Mosquito Commission, has been in existence since 1915. The buildings and grounds are now used solely for mosquito surveillance and control operations but for a time housed German prisoners of war during World War II, and Civilian Conservation Corps workers during the FDR years. Cape May County is a peninsula covering 277 square miles, two-thirds of which is comprised of marsh and woodlands. Much of these lands serve as habitat for the forty-five species of mosquitoes found in the county.
Everyone is aware of the "nuisance factor" mosquitoes create. This is especially important in Cape May County due to the influx of tourists during the summer season. In addition, mosquitoes are capable of transmitting disease. The Cape May County Department of Mosquito Control is acutely aware of this potential. Consequently, a great deal of effort is spent on the surveillance and control of those mosquitoes directly involved in the transmission of eastern equine encephalitis and West Nile virus among others. Eastern equine encephalitis which once reached epidemic proportions as recently as 1959 now only rarely affects humans. This is due in great part to the work of the mosquito control department. West Nile Virus was first isolated in North America in 1999 and has since spread rapidly in all directions covering nearly all of the continent. While most recover from the disease, those that are elderly or have compromised immune systems may experience long term adverse effects or even death. Animals may also be adversely affected by mosquito borne diseases. Both West Nile virus and eastern equine encephalitis are also threats to horses not inoculated against these diseases. In addition, dog heartworm is transmitted by mosquitoes and in canines not under treatment with a preventative medicine, death may occur as the worms enlarge and collect in the heart. Dog heartworm appears to be almost exclusively a disease of dogs; other domestic animals and humans are for the most part immune to infection. If a disease is present in the mosquito, it exits and infects the "host" through injected saliva when the mosquito first bites. The majority of the time, this saliva simply creates the itch most of us associate with a mosquito bite. The resulting itch and welt is simply your body's reaction and defense to this small amount of foreign substance.
Cape May County Department of Mosquito Control's Integrated Pest Management Program
Our Department consists of 15 full time employees who work year round performing a variety of tasks, all with the goal of suppressing mosquito activity in the county to a tolerable level. Additionally, 8 to 10 seasonal employees are hired between April and October. These dedicated people help carry out our Integrated Pest Management Program consisting of surveillance, water management and biological and chemical control. To explain further:
With sixty-three different mosquito species in the State, over forty of which occur in Cape May County, surveillance of nuisance and disease carrying mosquito populations is crucial. The Department employs a network of "dipping" stations, so named because of the tool used to collect larvae and pupae from the water, around the county to direct our larval control efforts.
An array of collection devices are used to evaluate adult mosquito populations, including N.J. Light Traps, CDC traps, gravid traps and resting boxes. These collections are important from several standpoints: they indicate how many mosquitoes are present, what species of mosquitoes are present (not all mosquitoes bite humans - some are strictly cold blooded feeders, i.e. frogs, turtles!), where the mosquitoes are at present and where they appear to be headed.
The Department's inspectors are state licensed commercial pesticide applicators who regularly answer complaints of mosquito activity phoned in by the public. Where legitimate activity is found, proper control measures are taken.
Both on the salt marsh and in the upland, water management, when done properly, eliminates standing water while enhancing the natural food web. Open Marsh Water Management (OMWM) is a technique used in the control of the salt marsh mosquito Aedes sollicitans, and is the result of the cooperative efforts of wildlife conservation agencies and mosquito control agencies. Through a series of ditches, mosquito larval depressions are connected to more permanent bodies of water, for instance, a tidal creek or salt marsh pond. This serves both to eliminate standing water, and allow predaceous fish access to any mosquito larvae that might remain.
The Department uses Bacillus thuringiensis israelensis (Bti) and Bacillus sphaericus (Bs), bacterial larvicides toxic to mosquito larvae, in a variety of formulations. Backpack sprayers and helicopter-mounted equipment apply granular formulations of Bti & Bs. Truck mounted tank sprayers dispense a liquid formulation of Bti.
The Department stocks appropriate sites with mosquito eating fish (Gambusia affinis). These fish in return help suppress the aquatic populations of mosquitoes. These fish are available to the public upon request for use in ornamental ponds where no fish are present, or in other potential mosquito larval habitats.
When source reduction, water management and biological methods do not sufficiently reduce mosquito populations, chemical control is the last option. Larvicides are pesticides designed for application directly to water to control mosquito larvae. Adulticides are pesticides used in ultra low volume (ULV) spraying to control adult mosquitoes. ULV spraying is the modern day equivalent to the fogging operations conducted in the 1960s and 1970s. The Department’s commercial pesticide applicators follow the label instructions for all larvicides and adulticides and consult Rutgers University’s Insecticides Recommended for Mosquito Control in NJ in 2011. (http://www-rci.rutgers.edu/~insects/bmpmcnj.pdf)
Two larvicides in this category include methoprene and temephos. Methoprene is an insect growth regulator that disrupts the normal growth pattern of immature mosquitoes in water and prevents them from becoming breeding, biting adults. Temephos is an organophosphate pesticide registered by EPA in 1965 to control mosquito larvae and is the only organophosphate labeled for larvicidal use. It is an important resistance management tool for mosquito control programs. When used in rotation, the use of temephos helps prevent mosquitoes from developing resistance to the bacterial larvicides. Backpack sprayers and helicopter-mounted equipment apply granular formulations of methoprene and temephos. Truck mounted tank sprayers dispense liquid formulation of methoprene and temephos.
The Mosquito Department will utilize pyrethroid and organophosphate adulticides in 2011. Pyrethroids are synthetic (human-made) forms of pyrethrins. Pyrethrins, in turn, are insecticides derived from the extract of chrysanthemum flowers. The Mosquito Department will use five different pyrethroids in 2011, including etofenprox, permethrin, prallethrin, resmethrin and sumithrin. The Department configures and calibrates truck mounted ULV sprayers to apply all five pyrethroids. Also in use is malathion, an organophosphate, which is exclusively applied by our helicopter mounted ULV system. Malathion’s use is part of our resistance management program. Its application from our helicopter will be rotated with etofenprox when conditions necessitate.
For the latest information on pesticides used in mosquito control, visit the National Pesticide Information Center.
Cape May County Department of Mosquito Control
P.O. Box 66
Cape May Court House, NJ 08210