Ultra-low volume (ULV) application of pesticides has been defined as spraying at a Volume Application Rate (VAR) of less than 5 L/ha for field crops or less than 50 L/ha for tree/bush crops. VARs of 0.25 – 2 L/ha are typical for aerial ULV application to forest or migratory pests. In order to maintain efficacy at such low rates, droplet size must be rigorously controlled in order to minimise waste: this is Controlled Droplet Application (CDA).[1] Although often designed for non-evaporative (e.g. oil-based) formulations, ULV equipment may sometimes be adapted for use with water, often at Very Low volume (VLV: 5-20 L/ha) VAR.