Fate of plant-derived secondary metabolites in three moth species (Syntomis mogadorensis,Syntomeida epilais,andCreatonotos transiens)

Summary Larvae of three moth species were compared with respect to strategies used to cope with secondary metabolites (allelochemicals) present in their diet.Syntomeida epilais is monophagous and accepted only oleander (which contains cardenolides, CG). CG were detected as stored products in the larvae and also in the faeces and exuviae. Pure CG (digoxin and gitoxin) which do not occur in oleander fed on oleander leaves were sequestered as the oleander CG.Syntomis mogadorensis is polyphagous: given a choice larvae avoided plants with a high load of allelochemicals. Upon shortage of preferred plants they ate a wide variety of plants which contain alkaloids, terpenes, or phenolics. Of these allelochemicals, alkaloids and CG were mainly recovered in the faeces and only minute fractions in the larvae.Creatonotos transiens larvae behaved similarly toSyntomis in terms of polyphagy and non-resorption. However, the larvae took up and stored pyrrolizidine alkaloids (PA) such as heliotrine selectively.Creatonotos is thus polyphagous (a generalist) but also a PA-specialist which exploits PA as defensive agents, as a morphogen for the male pheromone gland, and as a precursor for the male pheromone.Abbreviations CG cardiac glycosides - IG iridoid glycosides - PA pyrrolizidine alkaloids - GLC gas liquid chromatography - MS mass spectrometry