Cucullia verbasci. Mullien Shark. The caterpillars of this moth are very destructive to Verbascums in June and July. Mr. Curtis describes them as being "about two and a half inches long, bluish white and thickly sprinkled with black and bright yellow spots; when touched, they emit a considerable quantity of dark green fluid from their mouths. When they have attained their growth, they burrow into the ground at the roots of the plant on which they have been feeding, and in a few days form a cocoon made principally of half rotted leaves and fine mould, and bound firmly together with silk, so as to resemble a stone, or a small lump of earth. They remain in this state till the following May, and sometimes for two years, when they emerge as pretty blackish brown moths. The wings, when extended, measure between one and two inches across; the upper pair are brownish, clouded with black, and have on the inner edge a pale white patch, resembling the figure 3, or the Greek letter s; the lower wings are pale brownish, and sometimes nearly white, and have a broad dark border. We have seen those caterpillars in such abundance in some gardens, as to completely destroy all the different kinds of Mullein, and the nearly allied plants.

The only way to lessen their ravages, is to collect and kill the caterpillars." - Gard. Chron.