Université de Neuchâtel

Selective sequestration and metabolism of plant derived pyrrolizidine alkaloids by chrysomelid leaf beetles

Hartmann, Thomas ; Witte, Ludger ; Ehmke, Adelheid ; Theuring, Claudine ; Rowell-Rahier, Martine ; Pasteels, Jacques M.

In: Phytochemistry, 1997, vol. 45, no. 3, p. 489-497

Pyrrolizidine alkaloids (PAs) are assumed to function as plant defence compounds against herbivory. A number of adapted insects are known to sequester plant derived PAs for their own benefit. Here we summarize the chemical interactions between leaf beetles of the genus Oreina (Coleoptera, Chrysomelidae) and their host plants Adenostyles spp., Senecio nemorensis, and S....

Université de Neuchâtel

Toxins in chrysomelid beetles : Possible evolutionary sequence from de novo synthesis to derivation from food-plant chemicals

Pasteels, Jacques M. ; Duffey, S. ; Rowell-Rahier, Martine

In: Journal of Chemical Ecology, 1990, vol. 16, no. 1, p. 211-222

In the Chrysomelinae, it appears that de novo synthesis of chemicals for defense is the primitive state, and the sequestration of plant chemicals for defense the derived state. The derived state evolved through both the morphological and biochemical preadaptiveness of the homologous defensive glands. In the adults, we discuss one unique case of sequestration in exocrine defensive glands of...

Université de Neuchâtel

Distribution of autogenous and host-derived chemical defenses in Oreina leaf beetles (Coleoptera: Chrysomelidae)

Pasteels, Jacques M. ; Dobler, Susanne ; Rowell-Rahier, Martine ; Ehmke, Adelheid ; Hartmann, Thomas ; Pasteels, Jacques M. ; Dobler, Susanne ; Rowell-Rahier, Martine ; Ehmke, Adelheid ; Hartmann, Thomas

In: Journal of Chemical Ecology, 1995, vol. 21, no. 8, p. 1163-1179

The pronotal and elytral defensive secretions of 10 Oreina species were analyzed. Species feeding on Apiaceae, i.e., O. frigida and O. viridis, or on Cardueae (Asteraceae), i.e., O. bidentata, O. coerulea, and O. virgulata, produce species-specific complex mixtures of autogenous cardenolides. O. melanocephala, which feeds on Doronicum clusii...

Université de Neuchâtel

Sequestration of plant pyrrolizidine alkaloids by chrysomelid beetles and selective transfer into the defensive secretions

Rowell-Rahier, Martine ; Witte, Ludger ; Ehmke, Adelheid ; Hartmann, Thomas ; Pasteels, Jacques M.

In: Chemoecology, 1991, vol. 2, no. 1, p. 41-48

Oreina cacaliae and O. speciosissima (Coleoptera, Chrysomelidae) sequester in their elytral and pronotal defensive secretions pyrrolizidine alkaloids (PAs) as Noxides (PA N-oxides). The PA N-oxide patterns found in the beetles and their host plants were evaluated qualitatively and quantitatively by capillary gas chromatography/mass spectrometry (GC-MS). Of the three host plants...

Université de Neuchâtel

Sequestration, Maintenance, and Tissue Distribution of Pyrrolizidine Alkaloid N-Oxides in Larvae of Two Oreina Species

Ehmke, Adelheid ; Rahier, Martine ; Pasteels, Jacques M. ; Theuring, Claudine ; Hartmann, Thomas

In: Journal of Chemical Ecology, 1999, vol. 25, no. 10, p. 2385-2395

Oreina cacaliae and O. speciosissima are leaf beetles that, as larvae and adults, sequester pyrrolizidine alkaloid N-oxides (PAs) as defensive compounds from their host plants Adenostyles alliariae and Senecio nemorensis. As in most Oreina species, O. speciosissima is also defended by autogenously produced cardenolides (mixed defensive strategy),...

Université de Neuchâtel

Genetic and Environmental Sources of Variation in the Autogenous Chemical Defense of a Leaf Beetle

Triponez, Yann ; Naisbit, Russell. E. ; Jean-Denis, J. B. ; Rahier, Martine ; Alvarez, Nadir

In: Journal of Chemical Ecology, 2007, vol. 33, no. 11, p. 2011-2024

Chemical defense plays a central role for many herbivorous insects in their interactions with predators and host plants. The leaf beetle genus Oreina (Coleoptera, Chrysomelidae) includes species able to both sequester pyrrolizidine alkaloids and autogenously produce cardenolides. Sequestered compounds are clearly related to patterns of host-plant use, but variation in de novo...