Timarcha lugens is nowadays one of the most conspicuous endemic beetles of the high mountains of the Sierra Nevada. The conservation strategies to preserve the biodiversity of this high-mountain habitat are effective only if they are based on broad and accurate scientific knowledge. T. lugens is a singular organism in being monophagous on a common mountain cruciferous, and functioning as a keystone species in this community. Furthermore, T. lugens is an endemic species of a unique ecosystem within one of the world's biodiversity hot spots. However, due to several characteristics of its ecology and the management practices currently conducted in the Sierra Nevada, the short- and long-term conservation of this chrysomelid is threatened.