West Nile Update, From Press Conference

[Dallas, TX] – [Dallas County will continue our Aerial Spraying against West Nile Virus (WNV) in Phase II of the plan which includes the new cities which have opted in this week.  In response to citizens who may see aircraft spraying their non-targeted areas; there are several reasons why when an aircraft is seen spraying insecticide over a non-targeted area they are NOT actually spraying that area. The technology onboard this aircraft is very sophisticated and the target areas are sprayed with great precision.  County Judge Clay Jenkins received communication from the Centers for Disease Control (CDC) today confirming that they were extremely pleased with Dallas County’s decision in the implementation of our Integrated Mosquito Response Plan which includes Aerial Spraying and they lauded our approach and leadership throughout.  The effort is being funded with a combination of federal and state dollars.]

Phase II of Aerial Spraying begins this evening. Three (3) planes will cover an additional 82,400 acres, with a 2nd round in the same areas tomorrow.  Wheels go up around 8:30pm; spraying to begin 9pm through approximately 2am (Wednesday) and again in the same areas tomorrow (Thursday).

Duncanville, Sunnyvale, Seagoville, Rowlett, Wilmer, Mesquite (South of I-30), Ferris, and a small portion of Garland

Lancaster, Sachse, Glenn Heights, Hutchins, Cedar Hill, Balch Springs, Irving, Combine, DeSoto, Cockrell Hill

Zachary Thompson, the Director of Health and Human Services (DCHHS) will be providing a complete list of cities which have been Ground Sprayed by his crews and which are being designated to still be Ground Sprayed. For WNV information from DCHHS, go to: http://www.dallascounty.org/department/hhs/home.html.


  • spray patterns are programmed into onboard technology in advance of flight
  • the technology accounts for wind speed, direction, aircraft momentum and altitude to automatically adjust the flow rate of the product to the targeted areas
  • The offset (how far outside the target area the spray originates) is determined by many factors and can be as far as 1-1/2 to 2 miles away from target area when dropped.
  • The droplets of insecticide being sprayed average about 30 microns (about ¼ of the diameter of a human hair), are virtually invisible to the human eye, and are odorless and tasteless.
  • aircraft make turns in non-targeted areas to reach their intended (target) areas
  • Biologists are on the ground to document impact of the spray and to ensure that it is consistently reaching the targeted area.

For specific information regarding the aircraft technology, the Aerial Spray process and the chemical DUET, please go to: www.clarke.com or contact Clarke’s spokesperson Laura McGowan.

We continue to emphasize that although we, Dallas County along with our federal and state partners and local municipalities, are doing everything possible to combat the spread of WNV – the ultimate war will be won by citizens following the 4D-s of prevention:

DEET – use insect repellents that contain DEET, or any other EPA approved insect repellent
DRESS – Wear long, loose and light-colored clothing outside during dusk and dawn hours.
DRAIN – Remove all areas of standing water.  Change water in wading pools, pet dishes and birdbaths several times a week.
DUSK/DAWN – Protect yourself during dusk and dawn hours

Please remember that the fight against WNV is predicated upon citizens taking personal responsibility for their own environments as well as their community.  Please be sure to take preventative measures to eliminate stagnant water and water pools wherever possible.  If we are NOT vigilant with standing water, larvae can hatch and we could be looking at possibly more mosquito spraying or additional protocol having to be considered again.

  • Empty or get rid of cans, buckets, bottles, old tires, empty pots, plant saucers and other containers that hold water.
  • Keep gutters clear of debris and standing water. Remove standing water around structures and from flat roofs.
  • Change water in pet dishes at least once a day. Change water in wading pools and bird baths several times a week.
  • Fill in low areas in the yard and holes in trees that catch water.
  • Maintain your backyard pool or hot tub and be sure someone takes care of it if you are out of town.
  • Stock ornamental ponds with fish that eat mosquitoes.
  • Cover trash containers so they will not collect water.
  • Water lawns and gardens carefully so water does not stand for several days.
  • Repair any leaking plumbing and outside faucets.
  • Screen rain barrels and openings to water tanks or cisterns.
  • Keep drains and ditches clear of weeks and trash so water will not collect.

For regular WNV updates and maps, go to: http://www.dallascounty.org/department/public_info/westnile.php

Contact Information: Judge Clay Jenkins

Maria Arita, PIO

Regarding FUNDING (DSHS) contact
Carrie Williams, Director Media Relations

Regarding Clarke/Dynamic Aviation, Staging/Media Ops for Aerial Process, contact
Laura McGowan, Communications Director

For Map Specifics and GROUND SPRAYING Process
Zachary Thompson, HHS
Or, DSHHS PIO Patricia Huston