PRODUCTION OF CARDENOLIDES VERSUS SEQUESTRATION OF PYRROLIZIDINE ALKALOIDS IN LARVAE OF OREINA SPECIES (COLEOPTERA, CHRYSOMELIDAE)

Adult leaf beetles of the genus Oreina are known to be defended either by autogenously produced cardenolides or by pyrrolizidine alkaloids ( PAs) sequestered from the food plant, or both. In this paper we analyz e larvae of different Oreina species and show that the larvae contain the same defensive toxins as the adults in quantities similar to those released in the adults' secretion. Both classes of toxins are found i n the body and hemolymph of the larvae, despite their different origin s and later distribution in the adults. Larvae of sequestering species differed in their PA patterns, even though they fed on the same food plants. The concentration in first-instar larvae of a PA-sequestering species was similar to that in fourth-instar larvae. In all stages exa mined, the amount of PAs per larva did not greatly exceed the estimate d uptake of one day. Eggs of two oviparous species contained large con centrations of the adult's toxins, while neonates of a sequestering la rviparous species had no PAs.