Fact Sheet on Mosquito Control
 updated July 2009
 

Background

Authority

 ·        County of Gloucester Code Chapter 9.5 “Health and Sanitation” Article II “Mosquito Control Districts” provides County with the authority to create a mosquito control district.

·        The referenced code also provides the County with the authority to levy a special tax on all real and personal property subject to local taxation within the defined limits of a mosquito control district of not more than $0.25 per one hundred dollars of assessed value.  The current tax rate levied on the mosquito control districts is $0.01 per one hundred dollars of assessed value.

·        Mosquito Control Commission: Dr. Thomas K. Irungu (Director of the Three Rivers Health District), Dr. Charles McComb, and Mr. Charles Sterling.

·        The County gains this authority from Title 32.1 (32.1-187 – 32.1-197) of the Code of Virginia.

 Mosquito Control Districts

 ·        Five districts have been created to date:

-         York - established in 1986

-         Abingdon - established in 1988

-         Powhatan Chimney - established in 1995 (expanded to include Fosque Lane this year)

-         Dunlop Woods - established in 1997

-         Chiskiake Village, York River Pines, and York Shores - established in 2000

·        To develop new districts the BOS would need to:

-         Adopt an Ordinance to include the new areas

-         Hold a Public Hearing to levy the special tax on the defined area

The Target

·        The lifecycle of a mosquito:

-         egg - hatches when exposed to water

-         larva - lives in the water

-         pupa - lives in the water (does not feed)

-         adult - lives in the air

·        Attack any stage of development for control

·        Over 200 different species known to live in Virginia.  Some are out during the day but most are out after dark.  Few are known carriers of EEE and WNV.

What We Do

Surveillance

 ·        The County maintains several mosquito traps within the five districts.  The traps are used to:

-         Obtain mosquito counts (number of mosquitoes captured per time)

-         Identify prevalent species (screen for species associated with disease)

·        The traps are operated by volunteers and staff.

·        Results of mosquito count will be used as input to determine when control measures begin and end for the mosquito control season

Larviciding

 ·        Just as it sounds … larviciding takes the approach of attacking the mosquitoes during the larva stage when they are living in standing water.

·        We use two chemicals / delivery methods:

-         Altosid briquettes (methoprene)

§         Placed in standing water (ditches, etc.) within districts

§         150 day release period

§         Staff plans to distribute over 6,000 briquettes this spring and a similar amount later in the season (more than last year)

§         Less toxic to humans than table sugar

-         Vetrolex packets (Bacillus Sphaericus a biological pathogen of mosquito larvae)

§         Placed in standing water (ditches, etc.) within districts

§         30 day release period

§         Dissolvable packets provide a targeted placement by drivers during adulticiding activities over the summer

Adulticiding

·        Just as it sounds … adulticiding takes the approach of attacking the mosquitoes during the adult stage when they are flying.

·        Adulticiding usually starts in May dependent on results from surveillance.

·        We use either of two chemicals for adulticiding: Biomist or Duet

·        Application of Biomist or Duet via truck mounted ULV foggers (Ultra Low Volume)

-         Two trucks can typically cover all of the mosquito control districts within a period of one week.  Normal shift is from approximately 6 pm – 11 pm

-         Trucks/ULV equipment are calibrated to deliver 170ml/min @ a speed of 10 mph.  The equipment is capable of varying the application rate as needed to account for the vehicles’ actual traveling speed.

-         Persons with houses set-back further than 150-feet from the nearest road can fill out a permission form allowing the County to operate the trucks on their property.

-         County Staff

§         Licensed Commercial Pesticide Applicator as required by the state (James A. Diggs, Director of Buildings & Grounds, who is a full time employee)

§         Four part time drivers (all four returning) each hold Registered Technician licenses.

§         Two of the four drivers will work on any given weekday evening

What We Don’t Do

·        Anything outside of the five mosquito control districts

·        Routine daytime adulticiding (limited adulticiding has been conducted after hurricanes)

·       Aerial spraying via aircraft

Budget Facts

·        Revenue completely from special 1-cent tax

·        Mosquito control fund has “reserve” for use

-         As a rainy day fund (Isabel)

-         Purchase capital needs that are not annual requirements (new trucks or equipment)

Site Designed by Sandra Hogge