History of the Leavenworth Mosquito Control District
Prior to the
formation of the Leavenworth Mosquito Control District the Lions Club of Leavenworth had undertaken over a number of years
to raise funds for the aerial spraying of mosquitoes in the Leavenworth area. This spraying typically occurred shortly
before the Fourth of July. However in the late 90's this practice began to be challenged and spraying was suspended
in 2000 and 2001. Mosquito numbers in 2002 were high enough that the City of Leavenworth combined with the Chamber of
Commerce took responsiblity for a final aerial spray prior to the formation of the Leavenworth Mosquito Control District.
Funding was provided by the Lions Club. In the meantime Lions Club members had begun the process of preparing the question
of a Mosquito Control District to be put to the voters along with funding for it through taxes.
In the Fall of
2002 voters overwhelmingly approved the formation of a Mosquito Control District and its funding. Since a board
and an approved budget had to be in place prior to the approval of tax collection, no taxes were available for 2003.
The Lions Club generously donated about $20,000 in funds which they had collected for mosquito control. This along with
a small loan obtained in late 2003 financed the initial season of operation. In 2004 through 2006 taxes were assessed
based on property value. In 2006 the state informed the district that to continue such an assessment a levy
must be approved each year. The board therefore decided to collect taxes on a per parcel basis.
After the District was approved by the voters the Chelan County Board of Commissioners
accepted applications for the initial Mosquito Control Board and appointed 4 board members: these were Tom Guthrie,
Dayle Massey, Karl Pflugrath and Bill Luebke. A fifth Veronica Harrison was appointed by the city. President Tom
Guthrie and Secretary Treasurer Dayle Massey were the original board officers. Dayle Massey is the only remaining member
from the original board. He now serves as the Board President. Other obligations or poor health have resulted in the transition
of the other 4 members. Bill Luebke was the first to resign followed by Veronica Harrison and Karl Pflugrath. Becki
Subido was the first new member. Later she resigned. The newest member of our board is now Bob Kelly, who
replaced Ken Coffin, the city representative. Chester Marler now serves as Secretary Treasurer while Larry Meyer and Nick
Stemm have each served at least 5 years as board members.
The
board began meeting in early 2003 and soon became persuaded that the District activities should include larvaciding. A number
of Mosquito Control Districts were consulted. Manager Lorna Johnson of the Curlew Mosquito Control District was especially
helpful and agreed to provide some instruction and materials (forms and applicatiors) for the new District.
The
position of Manager was advertised and Manager Jenny Mullins was hired to begin May 1st . She took the information which
the Board had gathered and quickly obtained a permit and materials (including the larvicides Bacillus thuringiensis and monomolecular
film). She began the treatment of larval habitat as she searched for such sites by soliciting information from the public
as well as by scouting areas by truck and on foot. Later in the summer Central Washington Helicopters provided a tour
of the District and this resulted in the discovery of two ponds and an untreated swimming pool. In later years, complaints have
been used to eliminate backyard breeding areas as well as to pinpoint new treatment sites. By 2007 adults of the
nuisance mosquito Aedes vexans were virtually eliminated from the area. Only one was positively identified in 2007.
Large concentrations of Aedes vexans in 2003 and 2006 resulted in aerial spraying of the adulticide malathion.
In 2006 a concentration against the hillside east of East Leavenworth Road resulted in the spraying of 275 acres. In
2003 most of the district (except for the northern most end) was sprayed in late June. Complaints continued and the
area between Shore Street and the southern end of East Leavenworth Road was aerially sprayed again in late July following
a ground spray behind Alpine Heights in early July.
In 2004 Assistant David Wood was hired. He has
worked for us each year since then but was less available in 2007. In 2007 Assistant Bruce Hill was hired and provided
the majority of larvaciding assistance. These assistants have been an integral part of our success over the years, since
water levels in May and June result in a much greater area of larval habitat. They each have their own pesticide applicators
license and work independently in their assigned areas using their own vehicle.
In 2004 the treatment of storm
drain catch basins began. The introduction to the district of an economical long lasting material Bacillus sphaericus helped
to spread out the larvaciding work schedule. Bacillus thuringiensis continued to be the treatment of choice but in 2006
the use of methoprene was also adopted. It became clear in 2006 that Bacillus sphaericus was not effective against Aedes
vexans. Fortunately this discovery was made while there was still enough time to retreat the areas with Bacillus thuringiensis.
Lower water levels in 2004 and 2005 (record lows in 2005) combined with the knowledge of sites gathered in 2003 to
produce successful larvaciding years where no adulticiding was necessary. These years also had early high temperatures
so that larvaciding began April 1st. In 2006 and 2007 larvaciding was not needed until late April. Although water
levels were much higher in 2006 with flooding in the parks, control of mosquitoes along the rivers was quite successful.
The missed larva were due to high rains and runoff against the East Leavenworth hillside.
In 2007 water levels
were comparable to that of 2003. Successful control was achieved. Almost all sites had trap counts below ten.
However trap numbers at Waterfront Park and the Wheeler Woodland climbed in August to over 20 and 30 Culex per night.
The approach of West Nile virus means that we cannot afford to become complacent. We seek to improve our control efforts
as long as mosquito-borne disease remains a serious threat to our community.