Why can’t the spray be seen coming like before?
The spray that you used to see during mosquito spraying was produced by the use of diesel oil or fog oil. This oil acted as a carrier to help disperse the pesticide in the proper concentrations. Newer methods of spraying called ultra-low volume or ULV have eliminated the need for the oil and therefore, no fog is seen during the spraying. This newer method still provides effective control of mosquitoes and eliminates the adverse health and environmental effects of the oil.
