This plant is an introduced invasive pest in North America and Australia.

They start with egg laying in the fall laying their eggs on the undersides of leaves of new fall basal growth on its host plant, St. John's Wort (Hypericum perforatum).

[2] The larvae feed on the plants at night for around one month before burying themselves in the soil to pupate.

In late spring the adults emerge to feed heavily on the plants just before or after they begin flowering, approximately April or May in California.

Usually they find small crevices, hide under stones, or in soil cracks.