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|Type:||Artigo de periódico|
|Title:||Sequestration of pyrrolizidine alkaloids by larvae of Tellervo zoilus (Lepidoptera: Ithomiinae) and their role in the chemical protection of adults against the spider Nephila maculata (Araneidae)|
|Abstract:||Life stages of the primitive Australian ithomiine butterfly Tellervo zoilus and its larval host-plant, the apocynaceous vine Parsonsia straminea, were quantitatively assayed for pyrrolizidine alkaloids (PAs). PAs were found in all stages, mainly as N-oxides, being most concentrated in larvae and freshly-emerged adults. Although adults feed at various confirmed PA sources this probably does not compensate for losses, as wild-caught adults had considerably lower concentrations of PAs. The main alkaloid present in both freshly-emerged adults and in leaves of the host-plant was lycopsamine (1b), stored by butterflies in the N-oxide form. Its presence in higher proportion, in relation to intermedine (la), in larvae, pupae and adults of Tellervo in relation to the host-plants suggests the inversion of intermedine to lycopsamine by the insects. No 14-member ring macrocyclic PAs were detected in either food-plant or butterflies. Several other PAs were found in wild-caught adults reflecting visits to other PA sources. PAs were also found in high concentrations in freshly-emerged individuals of the danaine Euploea core bred on Parsonsia straminea. Wild-caught Danaus affinis had high PA levels acquired from adult feeding. Freshly emerged Euploea raised on Ischnocarpus frutescens and Danaus raised on Ischnostemma carnosum (both PA-free) were preyed on by the orb weaving spider Nephila maculata, and showed no PAs. In all cases where PAs were present, most butterflies were liberated, usually cut out of the web unharmed, by Nephila. The spider's response was not closely linked to PA concentration, however, and may also depend on hunger levels and previous experience with PA-containing butterflies. All control and other non-PA containing butterflies were consumed although rejection of some body parts of freshly-emerged Danaus affinis suggests that compounds other than PAs may be involved.|
|Subject:||sequestration of secondary compounds|
|Editor:||Springer Basel Ag|
|Appears in Collections:||Artigos e Materiais de Revistas Científicas - Unicamp|
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