The mode-of-action of the insecticidal crop protection product Flonicamid has not been elucidated at this time. An important feature of a piercing/sucking insecticide is its ability to rapidly inhibit feeding. Myzus persicae were acclimated to feeding chambers for 48 hours before replacing diet containing flonicamid and a non-metabolizable sugar (14C-inulin). Feeding rates were determined by measuring the amount of 14C-inuln recovered in the honeydew over a time course. These studies monitored both the cumulative increase of 14C-inuln in honeydew as well as by measuring the 14C-inulin in honeydew during timed intervals. Both methods gave qualitatively and quantitatively identical results. Myzus persicae stop feeding immediately after flonicamid exposure. On the other hand, mortality is delayed occurring about 40 hours following flonicamid exposure.