As its name indicates Foxglove Pug is associated with foxglove flowers as the sole food plant of the larvae is the foxglove where it feeds inside the flowers, especially on the stamens. The adult flies May to late July having over wintered as a pupa in loose earth. The broad grey cross bar with its edge kinked near the leading edge of the wing is a diagnostic identification feature. Being dependant on one plant it is only locally distributed in Caithness