Technical Abstract: Droplet size spectra from different sprayers used to generate sprays for controlling insects that may vector diseases were measured by a laser diffraction instrument. The objective of this work was to measure the droplet size generated by different sprayers with water- and oil-based spray solutions. Data from 215 replicated spray tests, comprised of 24 sprayers and 2 spray solutions showed a wide range in the droplet size spectra produced. The volume median diameter (DV0.5) measurements ranged from 4-223 µm. The droplet spectra produced by 18 different ULV sprayers with oil- and water-based spray solutions were further evaluated to examine the droplet size sprays that resulted across the full operating specifications of the sprayers, namely spray rate and pressure. As the spray rate increased, droplet size also increased. For sprayers whose pressure could be adjusted, as the pressure increased at the same spray rate, droplet size decreased. Six foggers, also evaluated, showed increases in droplet size with increases in spray rate. The information presented aids users in sprayer selection and operation to produce the specific droplet size spectra required for a particular application.