Cardiac glycosides in the Lygaeinae (Hemiptera: Lygaeidae)

Cardiac glycosides are shown to occur in brightly colored species belonging in most genera of the Lygaeid subfamily Lygaeinae. These insects appear to sequester these chemicals from their host plants. Several genera possess a special series of glands which appear to have as a principal function the concentration of these potent chemicals. Cardiac glycosides can also be detected in the other better known defensive secretions of these Hemiptera. It is concluded that most genera of Lygaeinae contain species that have the chemical basis for being protected. Their participation, as models, in mimicry complexes is thus suggested.