PRODUCTION OF CARDENOLIDES IN DIFFERENT LIFE STAGES OF THE CHRYSOMELID BEETLE OREINA-GLORIOSA

Cardenolide production in larval, pupal, and adult leaf beetles Oreina gloriosa (Coleoptera: Chrysomelidae) is compared. Significantly different levels of cardenolides were found in the various developmental stages of this species: early and late fourth-instar larvae (14 and 19 nmol, respectively), pupae (10 nmol), 1-day-old imagos (8 nmol). The developmental effects on individual cardenolides were considerable. Whereas fourth-instar larvae and pupae mainly produce diglycosides (periplogenin-3-O-[beta-D-xylopyranosyl-(1-->4)-beta-D-allopyranoside] and digitoxigenin-3-O-[beta-D-xylopyranosyl-(1-->4)-beta-D-allopyranoside]) and their corresponding monoglycosides, the mixture of cardenolides in adult beetles is clearly more complex, containing increased amounts of acetylated mono- and diglycosides. There were at least 13 different cardenolides in extracts of 1-day-old imagos, spanning a broader range of polarity than the highly polar cardenolides found in extracts of the immature beetles. The biological significance of these chemical differences is discussed.