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The Mission
of Leon County Mosquito Control is to train and empower its
employees to provide Leon County residents and visitors with
effective and environmentally sound mosquito control services.
Services and educational programs are provided to protect public
health and reduce human discomfort associated with large mosquito
populations.
LC Mosquito Control accomplishes its mission through source
reduction, public education, larva and adult mosquito control
services.
No animal on earth has touched more human lives than mosquitoes.
More people have died from mosquito-borne diseases than all who have
been killed in all the wars every fought. All three thousand species
are self-serving survivors. Mosquitoes predated humans by
millions of years and are adept at surviving in almost all climates.
Before mosquito netting was widely used, mosquitoes were the scourge
of rich and poor alike. At first, only the wealthy could
afford them, but as mosquito-borne diseases decimated farmers and
peasants, mosquito nets were distributed throughout villages and
towns.
Native tribes
created and passed down tales of how mosquitoes came to be, usually
involving blood-thirsty giants that walked the land. Native
peoples discovered plants and other methods, like smoky fires to
ward off the biting insects.
When Europeans
arrived, so did some of the more deadly mosquito-borne diseases like
malaria and yellow fever. Indians, who had no natural immunity
to such diseases soon suffered epidemics that wiped out entire
tribes. Early settlers struggled with growing crops and
livestock while battling the insistent pest. Mosquitoes are
drawn to carbon dioxide and particularly that of cattle.
Swarms of them would fly up the nostrils of cows and suffocate them.
Until the
realization that mosquito breeding occurred in standing water and
draining and ditching began, those who could, would move entire
families, tribes or villages to higher ground in the Carolinas or
North Georgia until cooler weather made coastal and flat lands more
habitable.
When one of Andrew
Jackson's scouts came through Tallahassee in 1818, he reported a
completely abandoned town, "except for an old Indian woman, recently
dead, lying near ashes and a dirt pot." Florida almost
didn't become a state because of mosquitoes. Northern states
were reluctant to include the "land of flowers," in the union.
Truck spraying as
a method of controlling mosquitoes has been around – though vastly
revised for public safety – since the 1940s. As far back as the
1920’s larviciding, usually by floating diesel fuel on standing
water was a common control practice. Environmentally safe and more
effective products are currently in use.
Leon County Mosquito Control was organized as a separate division of
Public Works in 1996. Until then, it was under Leon County Health
Department and its primary responsibility was in maintaining
drainage ditches where mosquitoes bred.
LCMC conducted the
first project to control malaria in a war zone. During WWII, many
international soldiers arrived for pilot training at the airfield
where Tallahassee Community College now stands. County officials
worried about strains of malaria entering the country.
Doak Campbell
Stadium sits in what was a wetland. Dr. Andrew Rogers, a staunch
“Gator” had it drained for mosquito control purposes and then had
the irony of seeing a “Seminole” football field built on the
grounds.
Leon County
Mosquito Control is a “dependent” division, meaning it is funded by
taxes through the Board of County Commissioners.
In Florida there
are 73 species of mosquitoes, of those, only a dozen or so are
considered of public health concern as disease vectors. Scientists
estimate there are forty thousand mosquitoes for every man, woman
and child alive on earth.
Mosquito-borne
diseases:
Malaria occurred in all 67 counties in Florida and was once a
major scourge. Imported by European colonists, malaria-infecting
mosquitoes made it into the New World in cargo and baggage and by
people with the disease.
Malaria was definitely a problem in Leon County in the 1800's and
early 1900's, with a death rate of 125-175 per 100,000 people. In
the 24 counties having the highest death rates (Leon County
included), these rates meant 20 – 60 percent of the population had
malaria.
When
Andrew Jackson arrived in Tallahassee in 1818, he described a
“vacant town.” Native Americans and European settlers had fled,
possibly to avoid the mosquito-borne malaria, or to escape the
conquering military.
Malaria prevention and reduction methods: Those who could afford it
often went north for the summer, to avoid exposure. Window
screening was the single most effective and inexpensive tool
introduced to fight malaria, as the disease-carrying mosquito would
sleep in dwellings during the day and attack at night when residents
were asleep. Mosquito sprays, agricultural and development drainage
practices and the use of anti-malarial drugs effectively curtailed
outbreaks of the disease in Florida. Until its use was banned, DDT
was used in the ten counties with the highest malaria death rates.
Tallahassee suffered from three epidemics of yellow fever in
1841, 1853 and 1867. But problems with mosquito-born diseases
appear to have been much greater in large coastal cities like Tampa
and Jacksonville. There was no case of yellow fever reported in the
U.S. in 2006.
West Nile Virus
is spread through the bite of some Culex mosquitoes, and is
closely related to St. Louis Encephalitis virus. West Nile Virus
was discovered in New York City in 1999 and has since become
established in the West Hemisphere. West Nile virus was commonly
found in humans, birds and other vertebrates in Africa, Eastern
Europe, West Asia and the Middle East.
Less
than one percent of humans bitten with a West Nile virus infected
mosquito will become ill. It is estimated the majority of the
population have been infected and remained symptom-free, or had mild
flu-like symptoms. West Nile Virus severe illness occurs mainly in
the very young or the elderly.
There
were no human West Nile Virus cases reported in 2006 in Leon
County.
St. Louis
Encephalitis: First recognized in St. Louis, Missouri in 1933,
epidemics of SLE have occurred in Florida, Central and South
America. Even during epidemics, only a small proportion of people
infected with SLE become ill. Substantial numbers of people are
infected with SLE virus, but do not develop the disease. The virus
is a permanent resident of Florida. Transmission is via wild birds
bitten by a Culex nigripalpus, a SLE-carrying mosquito. The
bird develops sufficient quantities of the virus to pass it one to
another biting mosquito, then to humans. Frequency and severity of
SLE symptoms are greater in those under ten years old or older than
60.
Sentinel chicken flock monitoring indicates when SLE antibodies are
present and alerts Mosquito Control to the possibility of a SLE
outbreak. Surveillance and mosquito breeding sites are key to
controlling SLE incidences.
Mosquito
habitats: Mosquitoes breed in permanent fresh and salt waters,
floodwaters and containers. Not all species react to the same
control chemicals.
In Leon County,
there are 43 different species of mosquitoes. The Asian Tiger Mosquito,
Aedes albopictus is the most common in urban areas. It was imported in used
tires that were recycled and shipped to the U.S. from Asia.
Methods of
control: include larviciding, the use of
non-toxic Bacillus thuringiensis israelensis
in briquette or pellet
form. A second larval control material is a corncob
granule formulation of Bacillus sphaericus. Bs is highly
specific to Culicine and Anopheline mosquitoes. It is also very
safe for non-targets and provides longer protection than Bti,
but is relatively ineffective against Aedine mosquitoes.
Other means include the insect growth regulator, methoprene,
applied to specific, difficult to treat locations and the
monomolecular surface film, Agnique, that is effective against
pupae. Finally, predatory mosquitofish can be introduced to
stand-alone ponds and pools.
Controlling adult populations:
Source Reduction
is the low-tech method of mosquito control and involved the
cooperation of residents who are vigilant about emptying standing
water found in ordinary objects like birdbaths, pet dishes, old
tires and the like. LCMC conducts free inspections of properties to
locate the source of mosquito breeding. Through community
education, residents learn how to make their outdoor spaces less
mosquito-friendly.
Adulticiding
refers to a technique used to kill
adult mosquitoes. |