After 175 West Nile infections and nine deaths in Dallas County, the county has declared a public health emergency and the city of McAllen is responding.
McAllen's Environmental Health and Code Compliance Department is answering the call after Dallas County requested their assistance in spraying to prevent more West Nile cases.
"We're going to be doing a ground assault; there is no approval for an aerial assault so we are going to do ground in the suburban area, supervisor Earl Lane said.
The six machines the crew of seven is taking with them will be filled with a pesticide that kills mosquitoes.
It sprays out certain droplets that hit the mosquitoes that drop them dead on contact, Lane said.
In preparation for the weeklong mission, the city of McAllen was sprayed last week.
"We feel safe here as of right now but we have one left here in case anything should happen, Lane said.
So far there are no reported cases of West Nile in the valley.
The state of Texas has 15 reported deaths due to West Nile this year compared to just two in 2011.
To prevent mosquitoes from breeding Lane says to make sure your lawn is not overwatered and your pools are kept clean.