spraying

Don't be alarmed if you see a crop duster buzzing over Richland and West Richland Thursday evening, it's be design.
Starting around dusk, 8:30pm, extensive aerial spraying will be done in the area to help curb mosquito issues this spring and summer...

Imagine you're trying to control noxious weeds on acres of shoreline.  Now, imagine having to treat them by hand with a spray bottle!