Qualified Applicator License (QAL) Category K – Health Related Practice Exam

The most effective droplet diameter for cold fogging to control mosquitoes is typically in the range of 15-30 microns. This droplet size is ideal because it allows for a balance between effective coverage of the area being treated and the ability of the droplets to remain airborne long enough to contact and control mosquitoes, which are small flying insects.

Droplets in the 15-30 micron range can drift with air currents, increasing their reach and improving the likelihood of coming into contact with mosquitoes, which might be resting in foliage or other surfaces. Additionally, droplets in this size range are small enough to evaporate slowly, providing a longer residual effect that enhances the efficacy of the pesticide used.

Choosing droplet sizes that are too small, such as 5-10 microns, may result in rapid dispersion and evaporation, reducing contact time with the target pests. Alternatively, droplets that are too large, like 30-50 microns, may settle quickly to the ground or other surfaces without effectively reaching the mosquitoes in the air. Thus, the 15-30 micron range is critical for maximizing impact while minimizing waste and ensuring efficient control of mosquito populations in treated areas.