Dosage of chemicals

In order to avoid any misjudgement about their real effect, semiochemicals should be tested at doses that are close to their biological range. For example, most chemicals, when tested at too high a dose, become repellent. Unfortunately, this aspect has often been overlooked in the study of varroa chemical ecology (for some examples see Milani, 2002). Dose-response studies, where the biological activity of a given compound is tested at different doses in a logarithmic scale, are mandatory in current research.